INTRODUCTION

Pyroxenites are defined as ultramafic rocks containing > 60% modal pyroxene [START_REF] Streckeinsen | To each plutonic rock its proper name[END_REF]. Spinel, garnet and olivine are the most common varietal minerals. Relative portions of the major minerals in pyroxenites are extremely variable so the lithologies range from orthopyroxenites, through websterites, to clinopyroxenites. In particular, in the shallow sub-continental lithospheric mantle these various types of pyroxenites form the second most common ultramafic rock-type after the spinel lherzolite-harzburgite series. Based on their abundances in ultramafic massif and shallow mantle xenolith suites, pyroxenites form < 10% of the directly sampled upper-mantle. Pyroxenites in the upper mantle have been implicated in the petrogenesis of MORB (Hirchmann and Stolper, 1996), OIB [START_REF] Hirschmann | Alkalic magmas generated by partial melting of garnet pyroxenite[END_REF][START_REF] Sobolev | An olivine-free mantle sources of Hawaiian shields basalts[END_REF], ferropicrites [START_REF] Tuff | Experimental constraints on the role of garnet pyroxenite in the genesis of high-Fe mantle plume derived melts[END_REF] and in source of some island arc magmas [START_REF] Schiano | Primitive CaO-rich, silica-undersaturated melts in island arcs; evidence for the involvement of clinopyroxene-rich lithologies in the petrogenesis of arc magmas[END_REF]. For these reasons, in the last thirty years several research studies focused on pyroxenite rocks and their origins. In spite of the large number of studies and the results so far obtained, the origin of pyroxenites is still controversial. Early work by Dick & Santos (1979) suggested that they are metamorphic segregations of the host peridotite, formed by dissolution and precipitation of pyroxene during plastic flow. [START_REF] O'reilly | Thermal and petrological structure of the lithosphere beneath Hannuoba, Sino-Korea craton, China: evidences from xenoliths[END_REF] suggested an origin by insitu melting to explain the features of pyroxenite xenoliths from China. Several Authors (for example [START_REF] Obata | The Ronda peridotite: garnet-spinel and plagioclase lherzolite facies and the P-T-trajectories of a high temperature mantle intrusion[END_REF][START_REF] Frey | The origin of pyroxenites and garnet pyroxenites from Salt Lake Crater, Oahu, Hawaii: trace element evidence[END_REF][START_REF] Irving | Petrology and geochemistry of composite ultramafic xenoliths in alkali basalts and implications for magmatic processes within the mantle[END_REF] considered the pyroxenites as the result of crystal precipitation from asthenosphere-derived silicate magmas passing through the lithosphere. The mechanism of liquid-crystal separation was considered to be dynamic flow crystallization ruled by filter-pressing. [START_REF] Allegre | Inplications of two-component marble-cake mantle[END_REF] suggested that pyroxenites are remnants of subducted oceanic crust, streaked out into lithosphere. An alternative hypothesis has been proposed by [START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF], who suggested that some pyroxenites represent highpressure crystal segregates from magma derived from melting of subducted ocean crust. [START_REF] Blicher-Toft | Lu-Hf isotopes systematics of garnet pyroxenites from Beni Bousera, Morocco: implications for basalt origin[END_REF] highlighted the importance of melt-rock replacement reactions between older pyroxenites, peridotite and percolating melts. Several studies [START_REF] Loubet | Trace elements in orogenic lherzolites reveal the complex history of the upper mantle[END_REF][START_REF] Lenoir | The recrystallization front of the Ronda peridotite: evidence of melting and thermal erosion of subcontinental lithospheric mantle baneath the Alboran Basin[END_REF] have suggested that mantle pyroxenites have been affected by partial melting after emplacement. Finally, Santos et al. (2002) and [START_REF] Brooker | Trace elements and Li isotope systematics in Zabargad peridotites: evidence of ancient subduction processes in the Red Sea mantle[END_REF] have suggested an arc setting for some pyroxenites.

In the Mediterranean area, mantle pyroxenites have been described for several occurrences. In northern Morocco, pyroxenites from the Beni Bousera massif have been described by [START_REF] Kornprobst | Le massif ultrabasiques de Beni-Buchera (Rif Interne, Maroc): etude des péridotites de haute temperature et des pression et des pyroxénolites à grenat et sans grenat qui leur sont associées[END_REF][START_REF] Kornprobst | Les péridotites et les pyroxénolites du massif ultrabasiques des Beni Bouchera: une etude expérimentale entre 1100°C et 1550°C sous 15 á 30 kb de pression séche[END_REF], [START_REF] Kornprobst | Corundum-bearing garnet clinopyroxenites at Beni Bousera (Morocco): original plagioclase-rich gabbros recrystallised at depth within the mantle)[END_REF], [START_REF] Pearson | Oxygen isotopes evidences of pyroxenites in the Beni Bousera Peridotite massif, North Morocco: derivation from subducted oceanic lithosphere[END_REF][START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF], [START_REF] Kumar | A major and trace element and strontium, neodymium, and osmium isotopic study of a thick pyroxenite layer from the beni Bousera Ultamafic Complex of northern Morocco[END_REF], Blichert-Toft et al. (1999), [START_REF] Pearson | Re-Os and Lu-Hf isotope constraints on the origin and age of pyroxenites from the Beni Bousera peridotite massif: implications for the mixed peridotite-pyroxenite mantle sources[END_REF] and [START_REF] Gysi | Petrogenesis of pyroxenites and melt infiltrations in the ultramafic complex of beni Bousera, Northern Morocco[END_REF].

In SE Spain, pyroxenites within the Ronda massifs were investigated by [START_REF] Zindler | Nd and Sr isotopic study of a mafic layer from Ronda Ultramafic complex[END_REF], [START_REF] Suen | Origins of the mafic and ultramafic rocks in the Ronda peridotite[END_REF], [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF], [START_REF] Garrido | Incompatible trace element partitioning and residence in anhydrous spinel peridotites and websterites from the Ronda orogenic peridotite[END_REF], Sanchez-Rodriguez & Gebauer (2000), [START_REF] Morishita | High-pressure aluminous mafic rocks from the Ronda peridotite massif, southern Spain: significance of sapphirine-and corundum-bearing mineral assemblages[END_REF], Santos et al. (2002) and [START_REF] Bodinier | Origin of pyroxenite-peridotite veined mantle by refertilization reactions: evidence from the Ronda peridotite (Southern Spain)[END_REF]. The Pyrenees massifs in SW France contain numerous examples of layered pyroxenites that have been studied by [START_REF] Polvé | Orogenic lherzolite complexes studied by 87Rb-87Sr: a clue to understand the mantle convection processes[END_REF], Loubet & Allègre (1982), [START_REF] Bodinier | Petrogenesis of layered pyroxenites from Lherz, Freychinède and Prades ultramafic bodies (Ariège, French Pyrénées)[END_REF], Downes et al. (1991).

Among the Alpine massifs, pyroxenites from Lanzo were studied by [START_REF] Bodinier | Geochemistry and petrogenesis of the Lanzo peridotite body, western Alps[END_REF], while Balmuccia pyroxenites were analysed by [START_REF] Sinigoi | Differentiation of partial melts in the mantle: evidence from the Balmuccia peridotite, Italy[END_REF] and [START_REF] Rivalenti | The relationship between websterite and peridotite in the Balmuccia peridotite massif (NW Italy) as revealed by trace elements variations in clinopyroxene[END_REF].

Pyroxenites also occur in the Malenco ultramafic complex [START_REF] Müntener | Titanian andradite in a metapyroxenite layer from the Malenco ultramafics (Italy): implications for Ti-mobility and low oxygen fugagity[END_REF][START_REF] Becker | Crustal trace element and isotopic signatures in garnet pyroxenites from garnet peridotite massifs from lower Austria[END_REF] and in numerous localities in the Eastern Alps [START_REF] Melcher | Petrogenesis and geotectonic setting of ultramafic rocks in the eastern Alps: constraints from geochemistry[END_REF][START_REF] Konzett | Metamorphic evolution of iron-rich mafic cumulates from the Otztal-Stubai crystalline complex, eastern Alps, Austria[END_REF].

Garnet-bearing pyroxenites have been described as enclosed in the mantle sequences from the External Jurassic ophiolites (northern Apennine, Italy) by [START_REF] Montanini | Exhumation history of a garnet pyroxenite-bearing mantle section from a Continent-Ocean transition (Northern Apennine ophiolites, Italy)[END_REF][START_REF] Montanini | Garnet clinopyroxenite layers from the mantle sequences of the Northern Apennine ophiolites (Italy): evidence for recycling of crustal material[END_REF].

Further pyroxenite occurrences include ultramafic Bohemian massifs, lower Austria, which were emplaced during the Hercynian orogeny and contain garnet pyroxenite layers [START_REF] Becker | Crustal trace element and isotopic signatures in garnet pyroxenites from garnet peridotite massifs from lower Austria[END_REF][START_REF] Becker | Effects of melt percolation on the Re-Os systematics of peridotites from a Paleozoic convergent plate margin[END_REF] and Cabo Ortegal massif (NW Spain; Gil [START_REF] Ibarguchi | Petrology of eclogites and clinopyroxene-garnet metabasites from the Cabo Ortegal Complex (northwestern Spain)[END_REF][START_REF] Girardeau | Pyroxene-rich peridotites of the Cabo-Ortegal complex (northwestern Spain): evidence for large-scale upper mantle heterogeneity[END_REF]Santos et al., 2002). Pyroxenite-bearing lherzolite bodies have been described at Zabargad island in the Red Sea (Egypt; [START_REF] Vannucci | Rare earth and trace element geochemistry of clinopyroxenes from Zabargad peridotite-pyroxenite association[END_REF]Piccardo et al., 1998;[START_REF] Brooker | Trace elements and Li isotope systematics in Zabargad peridotites: evidence of ancient subduction processes in the Red Sea mantle[END_REF].

Anhydrous spinel and garnet pyroxenites also occur as xenoliths in host alkali basalts from various European localities. Pyroxenite xenolith suites in France, Hungary and Romania have been studied by [START_REF] Downes | Textural, isotopic and REE variations in the spinel peridotite xenoliths, Massif Central, France[END_REF], [START_REF] Embey-Isztin | Mafic granulites and clinopyroxenite xenoliths from the Transdanubian Volcanic Region (Hungary): implications for the deep structure of the Pannonian Basin[END_REF], [START_REF] Wilson | Multiple enrichment of Pannonian-Carpathian Mantle: Pb-Sr-Nd isotope and REE constraints[END_REF], [START_REF] Dobosi | Oxygen isotopes ratios of phenocrysts from alkali basalts of the Pannonian Basin: evidences for an O-isotopically homogeneous upper mantle beneath a subductioninfluenced area[END_REF], [START_REF] Kovacs | Type II xenoliths and related metasomatism from the Nograd-Gomor Volcanic Field, Carpathian-PAnnonian region (northern Hungary-southern Slovakia)[END_REF]. Pyroxenites have been recently found [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF][START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] also in Middle Atlas (Morocco), where they are brought to the surface by lavas and pyroclastic products of the late Pliocene to Quaternary volcanism. From the lithological point of view, most xenoliths are lherzolites in composition, with subordinate harzburgites and pyroxenites. Whereas the lherzolite and harzburgite samples were studied in detail by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF], a comprehensive study of pyroxenitic rocks is still lacking. The present Ph.D. study is aimed at characterising the composition of pyroxenite xenoliths poured out by Cenozoic intraplate volcanism in various districts of Middle Atlas to unravel their origin and significance in the frame of the geodynamic evolution of the North-Africa lithospheric mantle. The interpretation is based on a combined petrological-geochemical approach and, particularly, on reliable geochemical information (i.e. trace element and isotopic signatures) at both bulk-rock and mineral scale. The data are used to address a largely debated and crucial issue, namely whether pyroxenites do represent ancient magmatic events or sectors of subducted crust recycled into the lithospheric mantle. A further goal is to understand at which extend Middle Atlas pyroxenites can be regarded as close analogues of pyroxenites from Beni Bousera ultramafic massif (Northern Morocco; [START_REF] Kornprobst | Le massif ultrabasiques de Beni-Buchera (Rif Interne, Maroc): etude des péridotites de haute temperature et des pression et des pyroxénolites à grenat et sans grenat qui leur sont associées[END_REF][START_REF] Kornprobst | Corundum-bearing garnet clinopyroxenites at Beni Bousera (Morocco): original plagioclase-rich gabbros recrystallised at depth within the mantle)[END_REF][START_REF] Pearson | Oxygen isotopes evidences of pyroxenites in the Beni Bousera Peridotite massif, North Morocco: derivation from subducted oceanic lithosphere[END_REF][START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF][START_REF] Kumar | A major and trace element and strontium, neodymium, and osmium isotopic study of a thick pyroxenite layer from the beni Bousera Ultamafic Complex of northern Morocco[END_REF]Blichert-Toft et al., 1999;[START_REF] Pearson | Re-Os and Lu-Hf isotope constraints on the origin and age of pyroxenites from the Beni Bousera peridotite massif: implications for the mixed peridotite-pyroxenite mantle sources[END_REF][START_REF] Gysi | Petrogenesis of pyroxenites and melt infiltrations in the ultramafic complex of beni Bousera, Northern Morocco[END_REF] and from the Ronda ultramafic complex (Southern Spain; Suen [START_REF] Suen | Origins of the mafic and ultramafic rocks in the Ronda peridotite[END_REF][START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF][START_REF] Garrido | Incompatible trace element partitioning and residence in anhydrous spinel peridotites and websterites from the Ronda orogenic peridotite[END_REF][START_REF] Sànchez-Rodrìguez | Mesozoic formation of pyroxenites and gabbros in the Ronda area (southern Spain), followed by Early Miocene subduction metamorphism and emplacement into the middle crust: U-Pb sensitive high-resolution ion microprobe dating of zircon[END_REF][START_REF] Morishita | High-pressure aluminous mafic rocks from the Ronda peridotite massif, southern Spain: significance of sapphirine-and corundum-bearing mineral assemblages[END_REF]Santos et al., 2002;[START_REF] Bodinier | Origin of pyroxenite-peridotite veined mantle by refertilization reactions: evidence from the Ronda peridotite (Southern Spain)[END_REF]. The close analogy among the Middle Atlas and Ronda, Beni Bousera pyroxenites is based on geodynamic considerations that predicts their provenance from a common, although largely heterogeneous, lithospheric upper mantle.

CHAPTER 1 -GEOLOGICAL SETTING 1.1 -THE MEDITERRANEAN REGION

The Mediterranean domain provides a present-day geodynamic analogue for the final stages of a continent-continent (i.e. Europe and Africa) collision orogeny. In this area, oceanic lithospheric domains originally present between Eurasian and African plates have been subducted and partially obducted, except for the Ionian basins and the southeastern Mediterranean [START_REF] Cavazza | The Mediterranean region -a geological primer[END_REF]Cavazza et al., Eds, 2004).

The present-day setting of the Mediterranean region is characterized by a system of connected fold-and-thrust belts and associated foreland and Neogene extensional basins [START_REF] Carminati | The role of slab detachment process in the opening of the western-central Mediterranean basins: some geological and geophysical evidence[END_REF]Jolivet & Faccenna, 2000, and references therein;Cavazza & Wezel, 2003, and references therein;Cavazza et al., Eds, 2004;Beccaluva et al., 2011, and references therein;Fig.1.1). These basins formed during the Cenozoic in five main regions: from east to west, the Alboran Sea, the Liguro-Provençal basin, the Tyrrhenian Sea, the Aegean Sea and the Pannonnian basin.

According to [START_REF] Jolivet | Mediterranean extension and the Africa-Eurasia collision[END_REF], paleotectonic reconstructions illustrate that the Neogene to Recent extension in the major basins is the result of backarc extension and/or collapse of the inner part of the thickened Alpine crust. Available tectonic scenarii show similarities from the Alboran, Tyrrhenian to the Aegean Sea: after a period of crustal thickening achieved in a cold thermal environment attested by high-pressure, low-temperature metamorphic complexes, internal thrusts were reactivated by extensional structures such as large-scale detachments, below which high-temperature metamorphic core complex were exhumed. This process led to attenuation and, locally, to the breakup of the previously thickened crust accompanied by an outward migrations of thrust front. Instead, the extension in the Liguro-Provençal basin was different, because this process was settled in a region only slightly deformed by the Alpine orogeny. According to [START_REF] Jolivet | Mediterranean extension and the Africa-Eurasia collision[END_REF], in the Mediterranean region the extension began in all basins almost contemporaneously. In contrast, [START_REF] Cavazza | The Mediterranean region -a geological primer[END_REF] and Cavazza et al. (Eds., 2004) suggested that the extensional basins are different in terms of both age and geological structures.

According to [START_REF] Cavazza | The Mediterranean region -a geological primer[END_REF] and to Cavazza et al. (Eds., 2004), the basins are floored by: 1 -remnants of the Permo-Triassic Neotethyan oceanic domains (Ionian-Libyan Sea and eastern Mediterranean); 2 -Neogene oceanic crust (Liguro-Provençal basin and Thyrrenian Sea); 3 -continental lithosphere thinned to a variable extent (Alboran and Aegean Sea) up to denuded mantle (Central Tyrrhenian Sea) and 4 -thick continental lithosphere (Adriatic sea).

Geophysical data and palinspatic reconstructions of the Ionian-Libyan Sea and the eastern Mediterranean (point 1) show the presence of old (probably Permian age) oceanic crust below a thick pile of Mesozoic and Cenozoic sediments. The Ionian Sea and the eastern Mediterranean are currently being subducted beneath the Calabria-Peloritani terrane of southernmost Italy and the Crete-Cyprus arcs, respectively. As regard the point 2, the Liguro-Provençal basin opened in the Burdigalian and rifting in this area (early Oligocene) caused the development of a series of graben in southern France and Sardinia, both on-land and offshore. The deepest portion of the Tyrrhenian Sea (the youngest Mediterranean basin) is floored by Plio-Quaternary oceanic crust.

Along its western and eastern margins, rift related grabens contain sedimentary deposits as old as Serravallian-Tortonian, thus marking the age of the onset of extension in this region [START_REF] Cavazza | The Mediterranean region -a geological primer[END_REF]Cavazza et al., Eds., 2004, and references therein). The basement of the Alboran and the Aegean Sea (point 3) consists of metamorphic rocks [START_REF] Cavazza | The Mediterranean region -a geological primer[END_REF]Cavazza et al., Eds., 2004;[START_REF] Duggen | Magmatic evolution of the Alboran region: The role of subduction in forming the western Mediterranean and causing the Messinian Salinity Crisis[END_REF]; according to [START_REF] Cavazza | The Mediterranean region -a geological primer[END_REF], the extension in these basins stared during Early Miocene. Finally, the Adriatic Sea floor consist of 30-35 km thick continental crust, whose upper portion is mostly made of a thick succession of Permian-Paleogene platform and basinal carbonates. In particular, the Adriatic Sea is surrounded by the flexural foredeep basins of the Appenines (to the west) and Dinarides-Albanides (to the east), where several kilometers of synorogenic sediments were deposited during the Oligocene-Quaternary. The Mesozoic Adriatic domains has been considered a continental promontory of the African Plate (i.e. Adria), includes not only what is now the Adriatic Sea but also portions of the Southern Alps, Istria, Gargano and Apulia [START_REF] Lustrino | The Central-Western Mediterranean: anomalous igneous activity in an anomalous collisional tectonic setting[END_REF].

The system of connected fold-and-thrust belts that characterized the Mediterranean region varies in terms of timing, tectonic setting and internal architecture. From west to east the major orogenic belts are (Fig. 1.1): the Atlas system (for details see paragraph 1.2.1), the Rif, the Tell, the Betic Cordillera, the Pyrenees, the Alps, the Appeninne and the Carpathians. These Mediterranean orogeny have been traditionally considered collectively as the result of an "Alpine" orogeny, when instead they are the results of diverse tectonic events spanning from the Late Triassic to the Quaternary (Cavazza & Wezel, 2003 and references therein;Cavazza et al., Eds., 2004). According to Cavazza et al. (Eds., 2004), a large wealth of data constrains the lithospheric structure of the various elements of the Mediterranean Alpine orogenic system and indicates that the late Mesozoic and Paleogene convergence between Africa-Arabia and Europe has totaled hundreds of kilometers. Such convergence was accommodated by the subduction zones. The Mediterranean orogenic system features several belts of tectonized and obducted ophiolitic rocks, which are located along often narrow sature zones within the allochthon and represent remnants of former extensional basins. Some elements of the Mediterranean orogenic system, such as the Pyrenees and the Greater Caucasus, may comprise local ultramafic rock bodies but are devoid of true ophiolitic sutures.

According to [START_REF] Cavazza | The Mediterranean region -a geological primer[END_REF], the Tell and the Rif are parts of the Maghrebides, a mountain belt running along the coast of north-west Africa and the northern coast of Sicily. In particular, the Tell is composed of rootless south-verging thrust sheets emplaced in Miocene time, whereas the internal portion of this belts is characterized by small blocks of European lithosphere composed of Paleozoic basement complex nonconformably overlain by Triassic-Eocene carbonate rocks. The rocks units of the Rif of northern Morocco have been subdivided into External Zones, Internal Zones and Flysch nappes. In particular, the Internal Zone is characterized by metamorphic rocks, the Flysch nappes consist of Early Cretaceous to early Miocene deep-marine clastic and the External Zone consist of Mesozoic-Tertiary sedimentary rocks deposited on the African margin. Finally, starting from the Early Miocene, the Internal Zone was thrust onto the Flysch nappes, followed by the development of a thin-skinned foldand-trusth belt in the External Zone. The main geological features of the Betic Cordillera (Spain) are similar to the Rif belt (i.e. the subdivision into External Zones, Internal Zones and Flysch nappes), where the Internal Zones is made of Mesozoic-Tertiary sedimentary rocks deposited on the Iberian margin of the Alpine Tethys and deformed by north-west directed, thin-skinned thrusting during the early-middle Miocene. Instead, the Internal Zones consists of Paleozoic-Mesozoic rocks affected by Paleogene-early Miocene regional metamorphism. The Pyrenees are characterized by a limited crustal root, in agreement with a small lithospheric contraction during the late Pyrenean orogeny, and by a Moho which shallows progressively toward their internal zones. Such geometry is typical of other Alpine-age Mediterranean chains (for example, western and eastern Carpathians and parts of the Apennines) and probably results from the extensional collapse of the internal parts of these orogens, involving structural inversion of trusth faults and lower-crust exhumation on the footwalls of metamorphic core complexes. Moving eastward, the Alpine arc is the product of continental collision along the former south-dipping subduction zone between the Adriatic continental domain of the African plate to the south and the southern continental margin of the European-Iberian plate to the north. The thickness of the lithosphere is about 200 km in the western Alps, while it is in order of 140 km along the central and eastern Alps. This is in agreement with the idea that the collisional coupling was stronger to the west. In fact, the eastern Alps are made up of tectonic units derived from Apulia, the Austroalpine nappes, while the western are exclusively made up by more external and tectonically lower units of the European margin, the Briançonnais terrane and the intervening oceanic units. Moreover, the western Alps include outcrops of metamorphic rocks (like blueschists and eclogite-facies rocks) formed at pressure up to 30 kbars at depths about 100 km. Such rocks have provided radiometric ages as old as 130 Ma, although widespread Eocene metamorphic ages constrain the timing of the collision. The Apennines were generated by limited subduction of the Adriatic subplate toward the west. This mountain belt is characterized by a series of detached sedimentary nappes involving Triassic -Paleogene shallow water and pelagic, mostly carbonate series and Oligocene-Miocene turbidites, deposited in an eastward migrating foreland basin. In particular, an ophiolitic nappe (Liguride unit) is preserved along the Tyrrhenian coast. The Apennines has low structural and morphological relief, involve crustally shallow rocks, and have been characterized by widespread extension in their backside. The Carpathians are a broad arcuate orogen, about 1.500 km long, which extend from Slovakia to Romania through Poland and Ukraine. It is possible to recognize three major tectonic assemblages [START_REF] Cavazza | The Mediterranean region -a geological primer[END_REF] and references therein): the Inner Carpathians (constituted by Hercynian basement and Permianlower Cretaceous rocks), the tectonic "mélanges" and the Outer Carpathains (formed by stack od rootless nappes made of early cretaceous to early Miocene turbidites). All these units are thrust towards the foreland and partly cover the shallow-marine/continental deposits of the foredeep.

According to Ellouza & Roca (1994), two distinct major compressive events are recognized: 1thrusting of the Inner Carpathians (early Cretaceous) and 2 -Outer Carpathians underwent thrusting (Oligocene-Miocene). The present-day arcuate shape of this orogenic belt and the recent seismic activity in the Romanian sector are mostly the products of Neogene eastward slab retreat and displacements along shear zones.

-Geodynamics of western Mediterranean

It is a common view that the western Mediterranean results from the interactions between European and African plates, with a set of small plates (Iberian and Apulian), trapped between the two major (Robertson & Dixon, 1984 and references therein;[START_REF] Carminati | The role of slab detachment process in the opening of the western-central Mediterranean basins: some geological and geophysical evidence[END_REF]Gelabert et al., 2000[START_REF] Jolivet | Mediterranean extension and the Africa-Eurasia collision[END_REF][START_REF] Cavazza | The Mediterranean region -a geological primer[END_REF]Cavazza et al., Eds., 2004;[START_REF] Beccaluva | Geodynamic control on orogenic and anorogenic magmatic phases in Sardinia and Southern Spain: Inferences for the Cenozoic evolution of the western Mediterranean[END_REF][START_REF] Lustrino | The Central-Western Mediterranean: anomalous igneous activity in an anomalous collisional tectonic setting[END_REF]. According to [START_REF] Cavazza | The Mediterranean region -a geological primer[END_REF] references therein) the relative motion path of the African plate with respect to the European plate from the Oligocene to the Recent can be divided into three phases: 1 -NNE-directed during Oligocene to Burdigalian time; 2 -NNW-directed from Langhian to early Tortonian time; 3 -NW-ward from the late Tortonian to present. An alternative hypothesis to the current configuration of the western Mediterranean has been proposed by Gueguen et al. (1998), where the geodynamics of Mediterranean is connected to the progressive west-to-east migrating Appeninic arc system and the Europe-Africa collision is the main result of this translation.

Furthermore, according to the Authors, recent geodetic data show that the "absolute" plates motion directed of Europe and Africa are north-east oriented and not north-west directed as usually assumed.

According to Gelabert et al. (2000, and references therein), three main stages characterise the evolution of western Mediterranean starting from the late Cretaceous (Fig. 1.2): 1 -Tethyan subduction; 2 -Iberian collision; 3 -post-collisional events. [START_REF] Jolivet | Mediterranean extension and the Africa-Eurasia collision[END_REF].

The first stage (from the late Cretaceous to the Eocene -Oligocene transition, i.e. from 84 to 35 Ma; Fig. 1.2) was characterized by roughly east-west-striking subduction. Tethyan oceanic lithosphere subducted both northward, under the Iberian plate, and southeastward, below the Austroalpine-Apulian plate. The result of this first stage are the nappe stacking and the high pressure metamorphism observed in the present Internal Zones of the orogenic belts and part of high-velocity mantle anomalies detected by tomographic studies.

The second stage (early Oligocene,Fig. 1.2) includes the collision between Iberia and the continental blocks of the Balearics, Corsica, Sardinia and Internal Zones of the orogenic belts. The SW-NE boundary was located between two domains: 1 -the remnants of oceanic Tethys eastward, including the "Maghrebian Tethys" North of Africa and 2 -continental Iberia and blocks connected (Balearics, Corsica, Sardinia an Internal Zones of orogenic belts) in the West. Additional NE convergences of Africa against Iberia built up stress in the trapped Iberian plate. During this stage, the absolute movement of the African plate to the north was reduced by half compared to its speed in the previous stage [START_REF] Jolivet | Mediterranean extension and the Africa-Eurasia collision[END_REF]. According to the Authors, the oceanic slab subducted below European plate began to retreat to the south. This retreat relaxed compressional stresses all over the mediterranean region and its effects were felt in the Carpathian region, forming the Pannonnian basin, and also in the Alps. Moreover, the Authors do not exclude slab breakoff and suggest that the decrease in the absolute speed of African plate caused: 1 -a reduction in the compression stress and 2 -an increase of the velocity in the slab retreat, which produced extensive stress in the main plate. For example, the nonlooked subduction below the Zagros at east of the collision zone and the thermal weakening of the African lithosphere above the Afar plume caused extensional stress which led to the fragmentation of the African plate, simultaneously to the formation of Arabian plate.

Finally, the third stage (from Oligocene to present, i.e. 30 to 0 Ma; Fig. 1.2) was characterized by the formation of extensional basins surrounded by arcuate orogenic belts. A fundamental feature of this third stage is the coeval extension and shortening. The extension results in thinning of continental areas, leading to uplift and fast cooling of Internal Zones of the orogenic belts; moreover, it generates oceanic areas (i.e. Algerian, Provençal and Tyrrhenian basins). As reported by [START_REF] Cavazza | The Mediterranean region -a geological primer[END_REF], a number of small continental microterranes (i.e. Balearic Island, Sardinia-Corsica, Calabria) rifted off to the European-Iberian continental margin and drifted toward S-SE, leading to the formation of thinned continental crust or small oceanic basins. According to Carminati et al. (1998, and references therein), in the western and central Mediterranean this extensional tectonics is interpreted as the accommodation of the extensional collapse of the over-thickened internal region of the Betic-Alboran-Rif during the Late Oligocene. The extensional tectonic results in very fast exhumation (up to 500°C/Ma) of deep crustal rocks and contributes to the final part of the exhumation history of the peridotitic bodies outcropping around the Alboran sea (southerner Spain and northern Morocco). The extensional collapse phase was accompanied by bimodal volcanism and plutonism with calcalkaline to Kalkaline affinity (see paragraph 1.1.2). Gelabert et al. (2002, and references therein) proposed three different mechanisms to explain interactions between extensional basins and folded belts in the western Mediterranean: 1collapse of an over-thickened crust; 2 -slab rollback and 3 -convective removal of lithospheric roots. The first mechanism has been suggested as an explanation of the origin of both the Alboran basin and Northern Tyrrhenian Sea. The slab rollback model has been proposed as a mechanism to explain both Betic-Rif Internal Zone west-translation, resulting in the formation of the Gibraltar arc and extension and frontal compression around the Tyrrhenian Sea, connected to the formation of the Calabrian arc. According to the Authors, slab rollback is the main mechanism in configuring the western Mediterranean. It has been also suggested that convective removal of lithospheric roots plays a major role in the formation of Alboran Sea. In the westernmost Mediterranean, Miocene subduction rollback of old Tethys oceanic lithosphere and the associated lithospheric upwelling are also the plausible mechanisms to explain the necessary uplift (1 Km approximately) along the African and Iberian continental margins to close the Miocene marine gateways, thereby causing the Messinian salinity crisis (i.e. the desiccation of the Mediterranean Sea; [START_REF] Duggen | Deep roots of the Messinian salinity crisis[END_REF], the shift in magma chemistry [START_REF] Wilson | Tertiary-Quaternary magmatism within the Mediterranean and surronding regions[END_REF]Cavazza et al., Eds., 2004;[START_REF] Duggen | Deep roots of the Messinian salinity crisis[END_REF][START_REF] Duggen | Post-collisional transition from subduction-to intraplate-type magmatism in the westernmost Mediterranean: evidence for the continental-edge delamination of subcontinental lithosphere[END_REF][START_REF] Duggen | Flow of Canary mantle plume material through a subcontinental lithospheric corridor beneath Africa to the Mediterranean[END_REF]Beccaluva et al., 2011 and references therein) observed in magmatic products (see paragraph 1.1.2) and the progressive delamination of subcontinental lithospheric mantle (continental-edge delamination) that affected both the lithospheric thickness and mantle flow beneath northern Morocco [START_REF] Duggen | Deep roots of the Messinian salinity crisis[END_REF][START_REF] Duggen | Post-collisional transition from subduction-to intraplate-type magmatism in the westernmost Mediterranean: evidence for the continental-edge delamination of subcontinental lithosphere[END_REF][START_REF] Duggen | Flow of Canary mantle plume material through a subcontinental lithospheric corridor beneath Africa to the Mediterranean[END_REF], and references therein). Legend -Rocks type: 1-tholeiites; 2 -Medium-K and high-K calcalkaline plutons (red circles: Eocene plutons from the Alps and adjacent Sava zone); 3 -medium-K and high-K calcalkaline volcaics; 4 -shoshonities; 5 -ultrapotassic volcanics; 6lamproites; 7 -carbonatites; 8 -intraplate volcanics; 9 -rocks from intraplate, large central volcanoes; 10 -volcanics from deep drillings (DSDP and ODP sites and Neapolitan area); 11 -pyroclastic and/or ignimbritic rocks. VV -Veneto volcanic district. From Cavazza et al. (Eds., 2004).

-Cenozoic magmatism in the western Mediterranean

As mentioned in the previous paragraph, during the Cenozoic a change in magma chemistry occurred in the Mediterranean and surrounding areas. In particular, several Authors [START_REF] Wilson | Tertiary-Quaternary magmatism within the Mediterranean and surronding regions[END_REF][START_REF] Duggen | Deep roots of the Messinian salinity crisis[END_REF]2005;Cavazza et al., Eds., 2004 and references therein;Beccaluva et al., 2011 and references therein) describe the systematic evolution from orogenic to anorogenic magmatism in the Carpathian-Pannonian region, in the Anatolian-Aegean area, in the Maghrebian belt, in Sardinia and in Southern Spain. The two magma types are often overlapped in space but generally are distinct in time and magmatic affinity [START_REF] Wilson | Tertiary-Quaternary magmatism within the Mediterranean and surronding regions[END_REF][START_REF] Duggen | Deep roots of the Messinian salinity crisis[END_REF][START_REF] Duggen | Post-collisional transition from subduction-to intraplate-type magmatism in the westernmost Mediterranean: evidence for the continental-edge delamination of subcontinental lithosphere[END_REF][START_REF] Lustrino | The Central-Western Mediterranean: anomalous igneous activity in an anomalous collisional tectonic setting[END_REF]Beccaluva et al., 2011 and references therein;Fig. 1.3) as it follows: 1 -the orogenic magmatic activity developed mostly during Late Eocene-Miocene times and was characterized by tholeiitic, calcalkaline, shoshonitic and ultrapotassic products; 2 -the anorogenic magmatism occurred during Late Miocene-Quaternary times and poured out tholeiitic to Na-alkaline products.

According to [START_REF] Wilson | Tertiary-Quaternary magmatism within the Mediterranean and surronding regions[END_REF] and Beccaluva et al. (2011, and references therein), the distinctive geochemical features for orogenic magmas are represented by subduction-releted components, which variously add Low Field Strength Elements (LFSE, such as K, Rb, Cs, Ba, Sr, U and Th) to the supra-subduction mantle wedge also in relation to the nature and mode of the subducted slab. The geochemical signatures of the orogenic magmas described by [START_REF] Beccaluva | Geodynamic control on orogenic and anorogenic magmatic phases in Sardinia and Southern Spain: Inferences for the Cenozoic evolution of the western Mediterranean[END_REF] suggest an evolution of the mantle sources, involving subduction of oceanic lithosphere followed by collision and recycling of continental crustal components back into the mantle. The gradual enrichment of LFSE elements, coupled with 87 Sr/ 86 Sr increase and 143 Nd/ 144 Nd decrease, which are generally observed moving from tholeiitic/calcalkaline to more potassic magmas, indicates that fluids/melts released by the slab into the overlying mantle wedge could be derived from subducted oceanic lithosphere with variable involvement of continental crust materials.

Geochemical fingerprinting of anorogenic magmas is based on the conventional OIB (Ocean Island Basalt) mantle end-member, such as HIMU (and FOZO) and Enriched Mantle EMI and EMII, which are considered to originate in the sublithospheric upper mantle as the result of longterm recycling of ancient slabs [START_REF] Wilson | Tertiary-Quaternary magmatism within the Mediterranean and surronding regions[END_REF][START_REF] Beccaluva | Geodynamic control on orogenic and anorogenic magmatic phases in Sardinia and Southern Spain: Inferences for the Cenozoic evolution of the western Mediterranean[END_REF]. As reported by Beccaluva and co-workers, systematic investigations of mantle peridotite xenoliths brought to the surface by alkaline lavas from Sardinia, Calatrava and Tallante indicate that metasomatising agents had a prevailing HIMU imprint for Calatrava, whereas a predominant EMI component is observed for Sardinia and Tallante. The addition of HIMU-like components seems to have been present in both European and North-African lithosphere since the Late Cretaceous [START_REF] Wilson | Tertiary-Quaternary magmatism within the Mediterranean and surronding regions[END_REF][START_REF] Downes | Formation and modification of the shallow sub-lithospheric mantle: a review of geochemical evidences from ultramafic xenolith suites and tectonically emplaced massif of western and Central Europe[END_REF], as indicated by the ubiquitous presence of this component in the sources of Cenozoic anorogenic provinces. Seismic tomography suggests that this component could be related to common sheet-like or diapir-like sublithospheric mantle domains (Beccaluva et al., 2011, and references therein), which extend from Eastern Atlantic to Europe, Mediterranean and North Africa. Consequently, the HIMU-like metasomatising agents rising from the convective mantle appear to have accumulated in the lower lithospheric portion and would result from recycling of altered crust, whereas EMI (the older metasomatic component) may have been better preserved in the upper, more rigid lithospheric mantle and requires, in addition, lower continental/pelagic components (Stracke et al., 2005).

Beccaluva and co-workers, in particular, have focused on the orogenic and anorogenic magmatic phase of Sardinia and Southern Spain in order to present a geodynamic evolutionary model, which can represent the systematic variation from these two types of magmatism. According to the Authors, the early orogenic magmatism took place along the Paleo-European-Iberian continental margin and developed with arc tholeiitic/calcalkaline magma in Provence and Sardinia (∼38-26 Ma) and in the Betic Cordillera (∼34-27 Ma). Petrological and isotopic characteristics of these rocks reflect initial stage of arc magmatism related to the subduction of oceanic lithosphere. Inter-arc rifting in the Paleo-European-Iberian continental margin developed from the Early Miocene, leading to the opening of the Ligurian-Balearic ocean basin and resulting in the southeastward drifting and rotation of the Sardinia-Corsica block (Fig. 1.4). The orogenic volcanic activity gradually ended in Sardinia (about 12 Ma) and in Spain (about 6 Ma) with high-K 2 O calcalkaline, shoshonite and ultrapotassic products, and was accompanied by a marked stepping of the subduction during the late stages of convergence. From Late Miocene, southeastward slab retreat and rollback induced rifting along the Internal Apennines and the Calabarian Alps leading to the opening of the Tyrrhenian basin and the southeastward migration of the Calabrian arc up to its present position. Relics of the subducted slabs, ponding over large areas of the mantle transition zone, appear to play a significant role also in genesis of anorogenic magmas, which occurred shortly after the end of an orogenic magmatic activity in Sardinia and in Southern Spain. In these regions, major anorogenic volcanic fields lie above the frontal part of the subducted slab, where convective instabilities could have triggered the melting process in the shallower mantle. The generation of anorogenic magmas is considered the result of mantle upwelling/decompression, heat transfer and reactivation of older (Pre-Paleozoic) metasomatic components, which take place at the periphery of the subducted slab. Relative to the orogenic magmatic phase, these processes occurred after a gap of 6 Ma in Sardinia and 0.4 Ma in the Southern Spain. Due to the slab roll back and inter-arc extension, the magma sources of the preceding orogenic cycle are completely replaced by "fresh" mantle material from which anorogenic magmas were then generated. The Authors conclude that the Cenozoic anorogenic volcanism may be interpreted as a far-field consequence of the Mediterranean orogenic process. This interpretation also means that the on-going subduction along the Apennine-Magherbian belt doesn't provide chemical sources of the anorogenic magmas, but represent a dynamic factor that activates magma-genesis remobilizing old metsomatised mantle domains.

-THE GEOLOGY OF MOROCCO

Morocco is located at a triple junction between a continent (Africa), an ocean (the Atlantic) and an active plate collisional zone (the Alpine belt system). This results in a rugged topography with a wide range of outcropping terranes spanning from Archaean to Cenozoic in age, as well as distinct tectonic systems including sedimentary basins and metamorphic fold belts. Two major geological events that took place in the Mesozoic and Cenozoic ruled the geological history and the present-day tectonics of Morocco: 1 -the opening of the North Atlantic and the western Tethys in the Early Mesozoic; 2 -the Africa-Europe continent-continent collision in Early Cenozoic time (Seber et a., 1996, and references therein).

Regarding the topography and the major geological domains, to the north the Rif range extends along the Mediterranean coast (Alboran Sea), maintaining the continuity of the Kabylian-Tellin belts (Maghrebides) up to the Strait of Gibraltar (Fig. 1.5). In particular, the Rif massifs are interplate mountains, characterized by numerous asymmetric, Alpine-type, complex nappe structures (Seber et al., 1996, and references therein). South of these coastal ranges, a domain of elevated plateaus or mesetas occur (Algerian High Plateaus and Oran Meseta, Moroccan Meseta), including intramontane basins (Missour and High Moulouya basins). Then the Atlas system rises up, providing a northern boundary to the dominantly low-elevation of the Saharan domain. In particular, Moroccan Meseta and Algerian High Plateaus are two rigid cores characterized by a thin or even lacking Meso-Cenozoic cover overlying more or less metamorphosed Palaeozoic strata (Frizon de [START_REF] Frizon De Lamotte | The two main steps of the Atlas building and geodynamics of the western Mediterranean[END_REF]Missenard et al., 2000).

Figure1.5 -Physiography of northwestern Africa with limits of the main natural regions and young mountain belts from [START_REF] Michard | An outline of the geology of Morocco[END_REF].

With the exception of the Rif and Atlantic areas, the elevation of most of the Morocco country is high. The High Atlas displays several massifs close to 4000 m high, including the highest peak of northern Africa (Jebel Toubkal; [START_REF] Seber | Three-dimensional upper mantle structure beneath the intraplate Atlas and interplate Rif mountains of Morocco[END_REF][START_REF] Frizon De Lamotte | The two main steps of the Atlas building and geodynamics of the western Mediterranean[END_REF][START_REF] Missenard | Crustal versus asthenospheric origin of relief of the Atlas Mountains of Morocco[END_REF][START_REF] Michard | An outline of the geology of Morocco[END_REF]. A branch of the Atlas system extends obliquely across the mesetan domain, namely the Middle Atlas, which exceeds 3000 m in elevation. The northern, sub-Saharan border of the main Saharan domain also rises forming a massive mountain belt, the Anti-Atlas. The latter achieves up to 2700 m in Jebel Saghro and even more in the Jebel Siroua, a dissymmetric volcanic complex ca.30 km large, which ranges from late Miocene to Pliocene in age (10.8 to 2.7 Ma; Frizon de Lamotte et al., 2008, and

-The Atlas System

The Atlas system (i.e. Anti-Atlas, Middle and High Atlas) is an intracontinental, autochthonous orogenic domain running from Morocco to Tunisia over 2000 km and developed over a continental crust, which was only slightly thinned during its pre-orogenic evolution [START_REF] Missenard | Crustal versus asthenospheric origin of relief of the Atlas Mountains of Morocco[END_REF][START_REF] Frizon De Lamotte | The Atlas System[END_REF]Fig. 1.7). The continental basement widely crops out in the chain interior and it is made up of Paleozoic rocks deformed during the Varisican orogeny (Frizon de [START_REF] Frizon De Lamotte | The two main steps of the Atlas building and geodynamics of the western Mediterranean[END_REF]. The Middle and High Atlas correspond to inverted Mesozoic intracontinental basins (Missenard et al., 2006 and references therein). According to [START_REF] Seber | Three-dimensional upper mantle structure beneath the intraplate Atlas and interplate Rif mountains of Morocco[END_REF], the Atlas Mountains are fundamentally different from the typical orogens located along convergent/collision plate boundaries, like the Himalayas, Andes or the Alps. Both Middle and High Atlas, indeed, lack many of the observed diagnostic geological features of intraplate mountains. Flyschs, nappes, regional metamorphism, ophiolites, granitoid inclusion and large-scale asymmetric deformation are missing in the Atlas Mountains. However, intrusions of gabbroic bodies of Upper Jurassic age are described by Frizon de Lamotte et al. (2000, and references therein) in the eastern part of the Central High Atlas. These mafic intrusions are interpreted as resulting from left-lateral transcurrent movements, but their origin, and their mode of emplacement as well, are still poorly addressed.

There is a general agreement that the Atlas Mountains developed along zones of crustal weakness inherited from rifting episodes associated with the opening of both the Atlantic and Tethyan oceans during to Early Liassic times (Frizon de Lamotte et al., 2000, and references therein; [START_REF] Missenard | Crustal versus asthenospheric origin of relief of the Atlas Mountains of Morocco[END_REF]. According to Frizon de Lamotte et al. (2000, and references therein), the fault pattern at the base of these basins is dominated by NNE-SSW trending normal faults along the Atlantic shoreline and within the Middle Atlas and by ENE-WSW trending faults along the Atlas main alignment. From the end of the Liassic up to the late Mesozoic regional subsidence affected the Atlantic margin, the Central and eastern Maghreb in Algeria and Tunisia.

According to Frizon de Lamotte et al. (2008), the geodynamic evolution of the Atlas system comprises two major periods: the pre-orogenic and the orogenic period. The first one lasts from the Triassic to the Late Cretaceous and is characterised by extensional episodes in an overall rifting context, which affected the Varisican crust. This initial rifting controls the subsequent evolution of the basins until their inversion during the Cenozoic. Frizon de Lamotte and coworkers emphasize the Liassic paleogeography of the Atlas Mountains (Fig. 1.8). They distinguish two provinces in the future Atlas system: an eastern province connected to the Tethys (Central and Eastern High Atlas and Middle Atlas) and a western province opened toward the Central Atlantic (Western High Atlas). The latter correspond to the Agadir and Essaouira coastal basins, which are parts of the Atlantic passive margin, deformed during the Atlas Orogeny. Both the Tethyan and Atlantic Liassic provinces are basically inherited from the Late Permian-Triassic rifting. In between the two provinces extended a poorly subsident high, referred to as the West Moroccan Arch (WMA), whose Triassic-Liassic cover was subsequently eroded. Only some parts of the WMA were possibly emergent during the Liassic, in particular the Marrakech High Atlas. Seismic and field data suggest two distinct extensional end-members during the preorogenic period. In the west (Argana Corridor, Essaouira Basin), Late Permian to Late Triassic rifting was followed by the formation of a sag basin with widespread evaporites and basaltic flows (Late Triassic-Early Jurassic boundary). In the northeast (Guercif Basin), Liassic to Late Jurassic extension dominates, whereas Triassic extension was more limited. However, the extensional structures are not restricted to these two end-members. An intermediate situation is found in the central and Eastern High Atlas and the Prerif Ridges, which combine Triassic and Early to Middle Jurassic syn-rift evolution. According to Frizon de Lamotte et al. (2008), during the orogenic period, the relative motions of the peri-Atlantic plates changed since Late Cretaceous, being then characterized by convergence between Africa and Europe. The geometry of lands and seas progressively evolved and, by the Santonian, the Middle Atlas depocenters were connected to the Atlantic through the "Phosphate Plateau". Locally, tectonic shortening of Senonian age leads to folding due to syn-sedimentary inversion of inherited faults from pre-orogenic period, with development of breccias along the faults and a clear unconformity of the overlying Eocene strata. However, the deformation remained weak and local, without important relief building. The Atlas domain was still submerged until the Middle Eocene, which correspond to the actual beginning of the Atlas orogeny.

-The Middle Atlas

The Middle Atlas region (Fig. 1.9) covers an area of approximately 13200 km 2 and comprises three structural zones corresponding to distinctive paleogeography domains during the Mesozoic: from north to south, the Tabular Middle Atlas ("Causse moyen atlasique"), the folded Middle Atlas ("Moyen Atlas plissé") and the Missour-High Moulouya basin ("vallée de la Haute Moulouya"; Harmand & Cantagrel, 1986;Frizon de Lamotte et a., 2008, and references therein).

The "Causse moyen atlasique" extends over the Western Meseta, the Tazekka basement and the Saiss Basin and consists of tabular Triassic-Liassic sequences mostly detached from Paleozoic basement (Frizon de Lamotte et al., 2008). According to [START_REF] Harmand | Synchronism entre tectonique compressive et volcanisme alcalin: exemple de la province quaternaire du Moyen Atlas (Maroc)[END_REF], the several tabular sub-units constituting the "Causse moyen atlasique" are separated by NE-SW trending faults. These ancient faults, which governed the Jurassic sedimentation, are seismically active; they are generally oriented N 40. The folded Middle Atlas is bordered by two NE-SW trending faults, i.e. the North Middle Atlas Fault (NMAF) and the South Middle Atlas Fault (SMAF), becoming the Aït Oufella Fault (AOF) to the S-W (Fig. 1.9). The SMAF-AOF fault are complex zones of south-east verging faults and duplex carrying the chain onto the Missour and High Moulouya Basins, where deformation propagates over several kilometres [START_REF] Frizon De Lamotte | The Atlas System[END_REF]. The "vallée de la Haute Moulouya" is the sedimentary cover of the Eastern Meseta that also exhibits mostly tabular Mesozoic-Cenozoic sediments, characterized by Liassic and mostly Middle Jurassic dolomites ("Dalle des Hauts Plateaux"; Frizon de Lamotte et al., 2008). The Neogene Guercif Basin is located on the northern termination of the Middle Atlas and allows the connection with the South-Rif Corridor to the west and the Oujda Plain to the east.

Regarding the folding process, several researchers (e.g. [START_REF] Laville | A restatement of the Mesozoic Atlasic Rifting (Morocco)[END_REF] proposed that folding initiated during Jurassic sedimentation (Frizon de Lamotte et al., 2008, and references therein). According to Laville and co-workers, the NE-SW to ENE-WSW trending anticlines correspond to left-lateral wrench faults in an overall strike-slip regime explaining also short E-W compressional ridges. In this scenario, the compressional and extensional structures are interpreted as basically coeval and developed progressively during the Early-Middle Jurassic, whereas compression would have dominated during the late Jurassic. According to Frizon de Lamotte et al. (2008), subsurface data show that these models do not sufficiently distinguish the Jurassic structures from those related to the Cenozoic inversion. Based on the analysis of seismic profiles and on detail stratigraphic mapping, according to Frizon de Lamotte and co-workers the Jurassic period is dominated by extensional tectonics and block faulting with development of half-grabens bounded by ridges in the hanging wall of major normal faults. The thickness changes in the Jurassic beds are linked to the extensional movement along the faults. The extensional regime lasted until the Upper Jurassic. The fan-like geometry of the Jurassic units is related to block tilting during the rifting and progressive sedimentary infill, whereas the anticline-syncline geometry results from the Cenozoic shortening, with the anticline ridges being located along the crest of the tilted blocks.

According to Frizon de Lamotte et al. (2008), the compressional regime leading to the inversion of the Middle Atlas Basin started during the Late Cretaceous, but culminated during the Late Eocene-Pleistocene. During the Late Cretaceous-Middle Eocene, the Middle Atlas was slightly submerged as shown by the occurrence of shallow water sediments. The uplift of the Middle atlas domain is not due to shortening and isostatic rebound, but to thermal process (lithosphere thinning; see section 1.2.3). In this context, it is worth noting the occurrence of Middle Miocene to Quaternary basaltic rocks with some precursor as old as Paleocene in the whole Middle Atlas province (see paragraph 1.2.3). According to Frizon de Lamotte et al. (2008, and references therein), the stratigraphy of the Neogene Guercif Basin indicates that it emerged at 6 Ma. This result can be extended to the Middle Atlas mountain range, where the study of vertical axis rotation of Plio-Quaternary basalts, shown by paleomagnetism, and the diffuse regional seismicity confirm the persistence of active tectonic activity within the chain itself.

-The Cenozoic volcanic history of Middle Atlas

The Cenozoic volcanism of the Atlas system is typically alkaline with intraplate affinity (alkali basalts, basanites, nephelinites and associated intermediate and evolved lavas), whereas in the Rif it evolved through time from calcalkaline to shoshonitic, and finally, to alkaline.

The Atlas volcanism is located within a SW-NE trending strip, underlain by thinned lithosphere [START_REF] Frizon De Lamotte | The two main steps of the Atlas building and geodynamics of the western Mediterranean[END_REF]Misenard et al., 2006;[START_REF] Duggen | Flow of Canary mantle plume material through a subcontinental lithospheric corridor beneath Africa to the Mediterranean[END_REF]). For this reason, Frizon de Lamotte et al. (2008) proposed to call this area the "Morocco hot line". This trend extends towards the Mediterranean coast near Oujda where it is dated from 6.2 to 1.5 Ma [START_REF] El Azzouzi | Evolution of the sources of Moroccan volcanism during the Neogene[END_REF], and in the Oran area, Algeria (from 4 to 0.8 Ma, [START_REF] Coulon | Postcollisional transition from calcalkaline to alkaline volcanism during the Neogene in Oranie (Algeria): magmatic expression of a slab breakoff[END_REF]. It could be connected with the linear trend defined by the Pliocene-Quaternary alkaline lavas of southern Spain and southern France.

The Middle Atlas basaltic province comprises the largest and youngest volcanic fields in Morocco. A hundred well-preserved strombolian cones and maars, oriented N170, occur along a N-S trend ca. 120 km long between El Hajeb and Itzer [START_REF] Harmand | Le volcanisme alcalin tertiaire et quaternarie du Moyen Atlas (Maroc): chronologie K/Ar et cadre géodynamique[END_REF][START_REF] Harmand | Synchronism entre tectonique compressive et volcanisme alcalin: exemple de la province quaternaire du Moyen Atlas (Maroc)[END_REF][START_REF] Frizon De Lamotte | The Atlas System[END_REF]Fig. 1.10). Some maar deposits (Tafraoute, Bou-Ibalrhatene) contain large and abundant lithospheric mantle xenoliths (spinel lherzolites, pyroxenites and subordinate harzburgites) and lower crustal (granulitic) ones. Numerous fluid basaltic flows emitted from the strombolian cones, some of them 30-50 km long, overlie the dolomitic limestones of the "Causse moyen atlasique". Based on K-Ar dating, [START_REF] Harmand | Le volcanisme alcalin tertiaire et quaternarie du Moyen Atlas (Maroc): chronologie K/Ar et cadre géodynamique[END_REF] Finally, the subalkaline basalts, richer in silica than the former types (SiO 2 = 52%), make up the El Koudiate cone and the associated 20 km long lava flows.

According to the available geochronology [START_REF] Harmand | Le volcanisme alcalin tertiaire et quaternarie du Moyen Atlas (Maroc): chronologie K/Ar et cadre géodynamique[END_REF][START_REF] El Azzouzi | Evolution of the sources of Moroccan volcanism during the Neogene[END_REF], the Middle Atlas Miocene volcanic events emplaced only nephelinites, from 14.6 Ma to 5.9 Ma. However, nephelinites also erupted during the Quaternary, around 16 Ma and 0.75 Ma.

Alkaline and subalkaline basalts, as well as basanites, seem to be exclusively Quaternary in age and the youngest published ages have been measured on basanites. The alkali basalts, basanites and nephelinites display strongly enriched incompatible element patterns (Fig. 1.11). Their geochemical signatures are typically intraplate alkaline, and hardly distinguishable from those of ocean island alkali basalts (OIB) and related rocks. The progressive enrichment in the most incompatible elements observed from alkali basalts to nephelinites is consistent with a decrease in the degrees of partial melting of an enriched mantle sources.

Sr, Nd and Pb isotopic ratios measured on alkaline lavas from Tamazert, Middle Atlas and Oulmès (El Azouzzi et al., 1999) and Oujda area [START_REF] Duggen | Post-collisional transition from subduction-to intraplate-type magmatism in the westernmost Mediterranean: evidence for the continental-edge delamination of subcontinental lithosphere[END_REF] indicate an enriched mantle sources, with almost no radiogenic Sr, showing rather variable Nd isotopic ratios and consistently rich in radiogenic lead. This isotopic signature is close to the HIMU end-member recognized in oceanic islands and it is frequently found in Cenozoic alkali basalts and basanites from Europe, western Mediterranean, northern Africa and eastern Atlantic islands (Madeira, Canary archipelago). According to [START_REF] Hoernle | Seismic and geochimical evidence for large-scale mantle upwelling beneath the eastern Atlantic and western and central Europe[END_REF]and references therein) and to Oyarzún et al. (1997), these lavas are interpreted to derive from a 2500 to 4000 km large giant asthenospheric plume, which would have ascended below these areas during the Early Tertiary/Late Jurassic, suggesting that the mantle upwelling feature may be relatively long-lived.

Recently, it has been suggested by [START_REF] Missenard | Crustal versus asthenospheric origin of relief of the Atlas Mountains of Morocco[END_REF], on the basis of six lithospheric profiles across northwest Africa, that the elevated topography of the Atlas system (se section 1.2.1) and the alkaline magmatism is due to mantle upwelling. Missenard and co-workers hypothesised that the asthenospheric plume is small, Cenozoic in age and it is similar to those described by Zeyen et al. (2005;and references therein) under the French Massif Central or the Eifel in Germany. Such a small plume may then be interpreted as one of several "escape valves" of a large hot reservoir deeper in the mantle postulated by [START_REF] Hoernle | Seismic and geochimical evidence for large-scale mantle upwelling beneath the eastern Atlantic and western and central Europe[END_REF]. According to [START_REF] Duggen | Flow of Canary mantle plume material through a subcontinental lithospheric corridor beneath Africa to the Mediterranean[END_REF], the high heat flow together whit gravity and geoid anomaly recorded in the northwest Africa, point to existence of an abnormally shallow lithosphere-asthenosphere However, according to Frizon de Lamotte et al. (2008), the small volume of Miocene to Quaternary lavas erupted within the Atlas domain seems hardly consistent with the activity of such a giant plume. In addition, their silica-undersaturated character implies small degrees of melting of their mantle sources. Moreover, the strong negative K spikes observed in incompatible multi-elements patterns indicate that their sources contained residual hydroxylbearing minerals (pargasite and phlogopite), a feature which implies that this sources was at lithospheric depths during partial melting. These minerals, which commonly form during magma-mantle interaction processes, could have formed when alkaline magmas rising from the large-scale Early Tertiary plume percolated through the sub-Atlas mantle [START_REF] Duggen | Post-collisional transition from subduction-to intraplate-type magmatism in the westernmost Mediterranean: evidence for the continental-edge delamination of subcontinental lithosphere[END_REF].

The thermal anomaly responsible for the lithospheric thinning beneath the Atlas volcanic fields could also have generated the Miocene to Quaternary alkaline volcanism. The corresponding partial melting would be linked to the thermal erosion of the base of the lithospheric mantle, previously enriched through metasomatic interaction with the Early Tertiary giant plume-derived magmas. This melting process might have started at around 15 Ma below the southern Middle Atlas, generating the Miocene nephelinites, and then propagated toward SW (Siroua, Saghro) and NE (Guilliz, Oujda) along the "Morocco Hot Line", crosscutting the earlier tectonic boundaries. The lack of correlation between the age and the geographic position of the Moroccan alkaline volcanoes is indeed typical of hot line and contrast with the regular trends observed for Hawaiian-type hot spot.

CHAPTER 2 -PETROGRAPHIC DESCRIPTION

-STUDIED AREA

The studied xenoliths were collected from different maars and strombolian cones in the volcanic district of Azrou-Timahdite. A Google image of the Middle Atlas basaltic province is reported in figure 2.1; the figure also shows the sampling location. In particular, most of the samples were collected from three maars about 1 km wide near Bou-Ibarhatene and Ibarhatene. Some samples come from Jebel Hebri and Bou-Tagaroine strombolian cones. Other samples were collected from lavas and pyroclastic deposits along the main road north of J.Hebri (location "Cote 2003"). Finally, the samples called "SAI" were colleted along the track north of Ibalrhatene, near the two Bou-Ibalrhatene maars. In Table 2.1 are reported the different locations with the respective sample name, coordinates and altitude.

Location

Sample name Coordinates

Bou-Ibalrhatene IBA (East maar) 2.1 -Xenolith occurrences, along with adopted sample names and their coordinates.

-PETROGRAPHY

Based on their mineral mode, the sampled xenoliths were divided in lherzolites, pyroxenites and harzburgites (the latter are largely subordinate). In total, the investigated samples include 32 lherzolites, 10 pyroxenites and 4 harzburgites (Fig. 2.2; see Appendix A for the petrographic descriptions). Most of the lherzolite samples were collected from Bou-Ibalrhatene and Ibalrhatene maar deposit. The other lherzolites were collected from Jebel Hebri, "Cote 2003", Bou-Tagaroine and along the road between Azrou and Timhadite, south of J.

Hebri. The majority of pyroxenites was collected from the Ibarlahtene maar deposit and consists 2.2. In the following paragraphs, the different lithologies will be described according to their texture.

-Lherzolites with granular texture

The lherzolites TAK11, TAK16, TAK18, TAK19, TAK21, TAK22, TAK23, KAD3, KAD6, K AD7, KAD14, HEBRI1, HEBRI2, HEBRI3, 2003-1, 2003-2, 2003-3, BOU1, BOU2 and BOU3 are characterized by granular texture (olivine: 50 -80%; orthopyroxene: 10% -30%; clinopyroxene: 5 -20%; spinel: 3 -7%; amphibole: 1 -5%). This texture is defined by medium to coarse poprhyroclasts of olivine and orthopyroxene surrounded by scarce, fine to medium neoblasts of olivine, orthopyroxene, clinopyroxene and spinel. In two lherzolite samples (KAD6 and KAD14, both spinel-free), neoblasts of brown amphibole also occur. In some samples, the neoblasts show mosaic equigranular texture. Moreover, several lherzolites show interstitial melt pockets, which are connected one to the other by intergranular veins. Within these melt pockets, small phenocrysts of olivine, pyroxene, euhedral plagioclase are observed; only in few samples, glass is altered. In sample BOU3, a single phenocryst of plagioclase has dimension of about 2.0 mm and it shows multiple twinning (Fig. 2.3). In the samples that contain melt pockets, both the porphyroclasts and the neoblasts show spongy rims (Fig.

-Lherzolites with porphyroclastic texture

In lherzolites TAK14, TAK15, TAK20, TAK24, TAK25, KAD1, KAD2, KAD5, KAD8, KAD9, KAD12, KAD15, SAI1 and SAI2 (olivine: 50 -80%; orthopyroxene: 5 -30%;

clinopyroxene: 5 -15%; spinel: 3-10%, amphibole: about 7%) the porphyroclastic texture is defined by medium to coarse porphyroclasts of olivine and orthopyroxene surrounded by extensive neoblastic crystallization of olivine, orthopyroxene, clinopyroxene and spinel.

Moreover, sample KAD5 is characterized by fine-grained crystallization of brown amphibole.

Sometimes, the neoblasts show mosaic equigranular texture (Fig. 2.9). Most of the samples are characterized by foliation due to the orientation of the grains. Several lherzolites show interstitial melt pockets that contain small phenocrysts of olivine, pyroxene, euhedral plagioclase and opaque minerals (Fig. 2.10). Fresh glass is observed in samples TAK24 and SAI1 (Fig. 2.11).

Moreover, in some samples with intergranular melt veins both the porpyroclasts and neoblasts show spongy rims. Finally, sample KAD12 is characterized by millimetric pyroxenitic bands, in which both clinopyroxene and orthopyroxene occur (Fig. 2.12).

In general, the porphyroclasts of olivine have size ranging between 0. The brownish or greenish spinel (grains size from 0.02 to 6.3 mm) is interstitial with respect to the other mineralogical phases (Fig. 2.16). In some samples, the spinel is also associated with the melt pockets and, in this case, it shows irregular and curvilinear grain boundaries. Moreover, rounded neoblasts of olivine are included in some spinel. In sample KAD5, the grains of brown amphibole have dimensions ranging from 0.23 to 1.8 mm. The brown amphibole forms clusters with mosaic equigranular texture (Fig. 2.17 and 2.18).

-Harzburgites with granular texture

In the harzburgites KAD4 and KAD10 (olivine: 80-88%; orthopyroxene: 10-18%; clinopyroxene: about 2%; Cr-spinel: accessory percentage) the granular texture is defined by medium to coarse porphyroclasts of olivine and orthopyroxene surrounded by scarce neoblastic crystallization of olivine, orthopyroxene, clinopyroxene and minor amount of brownish spinel. In particular, the sample KAD4 is crossed by basaltic veins that crystallise small phenocrysts of olivine, pyroxenes and opaque minerals.

In general, the porphyroclasts of olivine have size ranging between 1.3 and 15.0 mm. The olivine has tabular shape and shows kink-band deformations. Some grains show small inclusions of rounded neoblasts of spinel. The porphyroclasts of orthopyroxene (from 0.4 to 1.3 mm in size)

have anhedral shape and show clinopyroxene exsolution lamellae. Both the neoblasts of olivine and orthopyroxene differ from their porphyroclasts for the size (from 0.40 to 1.3 mm for the olivine and from 0.63 to 1.3 for the orthopyroxene), for the rounded shape and for the lack of deformation or exsolutions. The grains of clinopyroxene and brownish Cr-spinel occupy interstitial position with respect to the other grains. The clinopyroxene is also characterized by orthopyroxene exsolution lamellae and appears undeformed. Sometimes, the grains of clinopyroxene form corona-type structures around olivine porphyroclasts (Fig. 2.19).

-Harzurgites with porphyroclastic texture

In the harzburgites ZYA1 and ZYA2 (olivine: 70%; orthopyroxene: 25 -27%; clinopyroxene: 3%; Cr-Spl: 2%) the porphyroclastic texture is defined by medium to coarse porphyroclasts of olivine and orthopyroxene surrounded by wide fine-grained neoblastic crystallization of olivine, orthopyroxene and clinopyroxene. These neoblasts show mosaic equigranular texture. Both the porphyroclasts and the neoblasts show a preferential orientation.

The porphyroclastic harzburgite samples are, moreover, characterized by widespread melt pockets, consisting of fresh interstitial glass that contains small phenocrysts of olivine, pyroxenes and opaque minerals. Some grains of olivine and orthopyroxene are associated with the melt pockets. In this case, they are almost completely replaced by melt and its crystallization products (Fig. 2.20).

The porphyroclasts of olivine (from 1.1 to 12.5 mm in size) and orthopyroxene (from 1.0 to 5.0 mm in size) are characterized by tabular and anhedral shape, respectively, and kink-band deformation. The orthopyroxene porphyroclasts include small undeformed neoblasts of olivine and pyroxene (Fig. 2.21). The neoblasts of olivine and orthopyroxene (both about 0.30 -0.35 mm in size), on the contrary, have rounded shape and show a weak deformation only at the contact with the melt pockets. The grains of clinopyroxene occupy an interstitial position relative to the porphyroclasts and do not show any exsolution lamellae. Locally, some small inclusions of rounded neoblasts of olivine are included in the grains of clinopyroxene. Grains of brownish Crspinel with holly-leaf shape also characterize the sample ZYA2 (Fig. 2.22). They are always associated with melt pockets and are largely replaced by newly formed mineralogical phases.

-Pyroxenites

The pyroxenite samples were divided in two main groups on the basis of presence or absence of garnet. In particular, the samples TAK5, TAK6, TAK8, TAK9, TAK10, TAK12 are garnet-bearing websterites (clinopyroxene: 70 -90%; orthopyroxene: 2 -15%; spinel: 3-10%; garnet: 5%), whereas the samples TAK7, TAK13 and TAK17 are garnet-free websterites (clinopyroxene: 25 -65%; orthopyroxene: 5 -12%; olivine: 20 -25%; spinel: 5 -10%).

Finally, the sample BOU4 is garnet-free clinopyroxenite (clinopyroxene: 98%; olivine: 2%).

The garnet-bearing websterites are characterized by medium-to coarse-grained porphyroclastic texture, with fine-to medium-grained neoblastic cristallization of clinopyroxene and orthopyroxene. In some samples and only locally, the neoblasts show mosaic equigranular texture (Fig. 2.23). All the neoblasts (grain size from 0.38 to 2.1 mm) have rounded shape and are not deformed. Fresh cores of garnet (average 0.30 mm in size) are preserved; they are always surrounded by kelyphite (Fig. 2.24) In all the samples, the garnet is a secondary phase: it occurs as coronas around the grains of spinel (Fig. Interstitial grains of green Al-spinel are present in all samples and their size ranges from 0.5 to 3.60 mm (Fig. 2.31). Olivine-websterite samples TAK7, TAK13 and TAK17 differ as for the olivine texture and occurrence. In TAK7 sample, olivine is present both as porphyroclast (with kink-band deformations and size range from 3.50 -5.25 mm; Fig. 2.32) and as rounded neoblasts (about 0.5 mm in size and without deformation). In the samples TAK13 and TAK17, on the contrary, olivine occurs only as undeformed neoblast (Fig. 2.33). It has rounded, seldom tabular, shape and it is about 0.25 to 5.3 mm in size.

BOU4 clinopyroxenite sample is characterized by coarse-grained cumulate texture.

Subhedral clinopyroxene is the cumulus phase, whereas anhedral olivine seldom occupies the intergranular space (Fig. 2.34). The grains of clinopyroxene show spongy rims (Fig. 2.35) and the olivine is seldom associated with fine phenocrysts of euhedral plagioclase.

Radiogenic and stable isotope investigations (chapter 6, § 6.1 and 6.2-6.3, respectively)

have been carried out also on three pyroxenite samples described in previous studies of Morocco xenoliths. The first sample (IBA21c) was studied by [START_REF] Raffone | Gli xenoliti ultrafemici dell'Atlante Medio (Marocco Nord-Occidentale): petrologia e geochimica del mantello litosferico in un contest di rifting continentale[END_REF] and was collected from one of the Bou-Ibalrhatene maars. The sample was classified as garnet-bearing olivine-websterite (orthopyroxene: 68%; clinopyroxene: 20%; olivine: 5%; spinel: 6% and garnet ≤ 1) and it is portion of a composite xenolith. In general, the sample is characterized by coarse-grained granular texture. The garnet (often surrounded by kelyphite) is a secondary phase occurring as coronas around the grains of greenish spinel. [START_REF] Raffone | Gli xenoliti ultrafemici dell'Atlante Medio (Marocco Nord-Occidentale): petrologia e geochimica del mantello litosferico in un contest di rifting continentale[END_REF] also described small garnet grains without kelyphite rims. These garnets occupy an interstitial position between the spinel and the grains of garnet with kelyphite rims. The other two pyroxenite samples (TAK3 and TAK4) were studied by [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF]; they were collected from the Ibalrhatene maar and were classified as websterite (TAK3) and clinopyroxenite (TAK4). These samples possess a granoblastic texture with a foliation marked by garnet kelyphitisation in both samples. In particular, the paragenesis is garnet + orthopyroxene + clinopyroxene + spinel for TAK3 and garnet + clinopyroxene +s pinel + sapphirine + orthopyroxene for TAK4. According to [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF], garnet is a secondary phase in both samples, in which it occurs around spinel. Finally, sapphirine occurs with different textures in sample TAK4: i) as inclusion in spinel or clinopyroxene, ii) surrounding spinel at the garnet contact, and iii) as thin exsolutions in clinopyroxene. and clinopyroxenite TAK4 are from [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF].

mm

Cpx Ol

Literature data are reported in the diagrams for comparative purposes. Bulk rock major element data for lherzolites were compared with the compositions of Ronda lherzolites [START_REF] Lenoir | The recrystallization front of the Ronda peridotite: evidence of melting and thermal erosion of subcontinental lithospheric mantle baneath the Alboran Basin[END_REF][START_REF] Bodinier | Origin of pyroxenite-peridotite veined mantle by refertilization reactions: evidence from the Ronda peridotite (Southern Spain)[END_REF] and Lanzo (Northern Italy) peridotites [START_REF] Bodinier | Geochemistry and petrogenesis of the Lanzo peridotite body, western Alps[END_REF]. Whole rock major element chemistry of Morocco pyroxenites has been compared with selected bulk rock data from the Beni Bousera (Morocco) peridotite complex [START_REF] Kornprobst | Corundum-bearing garnet clinopyroxenites at Beni Bousera (Morocco): original plagioclase-rich gabbros recrystallised at depth within the mantle)[END_REF][START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF] and Ronda (Southern Spain; [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF][START_REF] Morishita | High-pressure aluminous mafic rocks from the Ronda peridotite massif, southern Spain: significance of sapphirine-and corundum-bearing mineral assemblages[END_REF].

Major whole rock data for Morocco pyroxenites have been also compared with the data reported for pyroxenite samples by [START_REF] Bodinier | Petrogenesis of layered pyroxenites from Lherz, Freychinède and Prades ultramafic bodies (Ariège, French Pyrénées)[END_REF] for French Pyrenees, by [START_REF] Brooker | Trace elements and Li isotope systematics in Zabargad peridotites: evidence of ancient subduction processes in the Red Sea mantle[END_REF] for Zabargad, by [START_REF] Bodinier | Geochemistry and petrogenesis of the Lanzo peridotite body, western Alps[END_REF] for Lanzo (Northern Italy) and by [START_REF] Xu | Evidence for crustal components in the mantle and constraints on crustal recycling mechanism: pyroxenite xenolith from Hannuoba, North China[END_REF] for China. The compositions of Beni Bousera pyroxenites [START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF] and of Ronda ultramafics [START_REF] Bodinier | Origin of pyroxenite-peridotite veined mantle by refertilization reactions: evidence from the Ronda peridotite (Southern Spain)[END_REF][START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF] have been shown also in the trace element diagrams.

-MAJOR ELEMENTS

-Peridotites

The few studied samples of Morocco lherzolites show homogeneous compositions in terms of major elements (Table 10, Appendix B). In general, the Mg-number (100*Mg/(Mg+Fe tot )) is about 88 and the SiO 2 content is comprised between 43.9 and 45.0 wt%. MgO and CaO contents range from 38.5 to 39.6 wt% and from 2.82 to 3.38 wt%, respectively.

The Morocco lherzolites show SiO 2 contents similar to those described by [START_REF] Bodinier | Geochemistry and petrogenesis of the Lanzo peridotite body, western Alps[END_REF]Fig.3.1A, B and C) for the Lanzo lherzolites. In general, the Al 2 O 3 , CaO and MgO contents of the studied lherzolites are similar to those reported for Lanzo [START_REF] Bodinier | Geochemistry and petrogenesis of the Lanzo peridotite body, western Alps[END_REF] and Ronda (Lenoir et al., 2001) lherzolites (Fig.3.1A, B and C). Finally, the Morocco lherzolites differ from their analogues from Ronda [START_REF] Bodinier | Origin of pyroxenite-peridotite veined mantle by refertilization reactions: evidence from the Ronda peridotite (Southern Spain)[END_REF] 10). The analyzed samples, however, show marked chemical differences as for the SiO 2 and Al 2 O 3 contents. Indeed, on the basis of the SiO 2 content, the Morocco pyroxenite samples can be divided in two main groups (Fig.3.3A,B and C;Fig.3.4A,B and C;Fig.3.5A,B and C). In addition to its lowest Mg# content, Grt-bearing websterite TAK5 is characterised by the lower SiO 2 content (42.8 wt%) relative to the other Morocco pyroxenites, which show a SiO 2 content ranging between 46.8 and 49.9 wt%. In particular, the SiO 2 content of TAK5 sample is similar to that of the pyroxenites TAK3 and TAK4 [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF]. Pyroxenites TAK3, TAK4 and TAK5 also display similar values of Al 2 O 3 (ranging from 17.8 to 22.4 wt%), which are higher in comparison with the other studied Morocco pyroxenites (Al 2 O 3 comprised between 4.6 to 12.6 wt%; Fig.3.3A,B and C). Similar low values of SiO 2 associated with relatively high Al 2 O 3 contents are described only for some Beni Bousera pyroxenites [START_REF] Kornprobst | Corundum-bearing garnet clinopyroxenites at Beni Bousera (Morocco): original plagioclase-rich gabbros recrystallised at depth within the mantle)[END_REF]Fig.3.3A) and for the sapphirine-bearing pyroxenites described by [START_REF] Morishita | High-pressure aluminous mafic rocks from the Ronda peridotite massif, southern Spain: significance of sapphirine-and corundum-bearing mineral assemblages[END_REF]Fig.3.3C) for the Ronda ultramafic complex.

The other Morocco pyroxenites show SiO 2 and Al 2 O 3 values that are similar to those reported in the covariation diagrams for other occurrences for comparative purposes (Fig. 3.3A, B and C). The two groups of pyroxenites show a similar range of CaO and MgO contents; the former vary from 9.0 (Ol-websterite TAK13) to 15.1 wt% (Grt-websterite TAK9), whereas the latter are between 17.5 (Grt-websterite TAK5) and 26.1 wt% Fig.3.4A,B and C;Fig.3.5A,B and C). In general, these values for CaO and MgO are very close to those reported for the pyroxenites from Beni Bouesera, Lanzo and French Pyrenees. Two samples fall out from the range reported above for CaO and MgO values, namely the granular clinopyroxenite BOU4 and the Ol-websterite TAK7. BOU4 clinopyroxenite show significantly higher CaO contents

-TRACE ELEMENTS

-Peridotites

The selected three samples of lherzolites show similar chondrite-normalized REE patterns (Fig. 3.6; data reported in Table 11, Appendix B). The lherzolite samples are characterized by almost flat patterns in the MREE to HREE region (below 10xC1). All the samples show variable secondary LREE enrichment, with the lowest and highest enrichment shown by KAD1 and HEBRI3 samples, respectively. The REE patterns for the lherzolite samples are comparable with those reported by [START_REF] Bodinier | Origin of pyroxenite-peridotite veined mantle by refertilization reactions: evidence from the Ronda peridotite (Southern Spain)[END_REF] for the Ronda lherzolites.

These samples are also characterized by flat pattern in the MREE to HREE region below 10xC1, but they differ from the Morocco lherzolites for the LREE depletion. The lherzolite also show a progressive REE/LILE and REE/HFSE fractionation trend (Fig. 3.7) In particular, KAD1 and 2003-1 samples show marked negative Hf anomalies.

-Pyroxenites

The Morocco pyroxenites show a wide range of REE abundances and variable chondritenormalized REE patterns (Table 11, Appendix B). On the basis of the REE patterns, the studied samples were divided in four groups (Fig. 3.8).

The first group is represented only by BOU4 clinopyroxenite. The whole rock REE pattern for this sample is similar to that of its clinopyroxene (Fig. 3.9) and is characterised by a convex upward LREE pattern and an overall fractionation from MREE to HREE. The bulk rock REE pattern confirms that the sample underwent late percolation by alkaline agents. Noticeably, the bulk rock is significantly enriched in LILE and HFSE relative to the clinopyroxene that is by far the major host for trace elements in this rock sample (Fig.3.10). This suggests the presence of tiny accessory phases (not detected under the microscope), or, most probably, the presence of melt pockets and veins accounting for the whole trace element budget.

The second group is formed by TAK3 Grt-bearing websterite. This sample differs from the other Morocco pyroxenites for the higher HREE content (Fig. 3.11). TAK3 sample shows a spoon-shape whole-rock REE pattern, with high HREE abundances, depletion in MREE and enrichment in LREE. As for HREE and MREE, the TAK3 whole-rock pattern is comparable with those described by [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF] for the Ronda group A pyroxenites; it is also similar to that of graphite-garnet pyroxenites from the Beni Bousera peridotite complex [START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF]. The C1 normalised pattern for an extended series of incompatible trace elements (Fig. 3.12) shows positive Ba and Ta anomalies (below 100xC1) and a slightly negative Nd anomaly. In particular, the LILE and HFSE (with the exception of Ta) patterns of TAK3 sample are similar to those of group A Ronda pyroxenites [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF], although the concentration levels of these latter are lower. Noticeably, [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF] interpreted the group A pyroxenites as the vestiges of an old, veined subcontinental lithosphere.

The third group of pyroxenites consists of five Grt-bearing websterites (TAK5, TAK6, TAK8, TAK9 and TAK10). Their whole rock REE patterns differ from that of TAK3 Grtbearing websterite for the low HREE concentrations. The patterns of group 3 pyroxenites are almost flat in the MREE to HREE region (around 6.5xC1, Gd N /Lu N =1.1; Fig. 3.13), without positive Eu anomalies. These patterns also show variable secondary enrichment in LREE. These patterns are comparable with those of some group A Ronda pyroxenites [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF] and Grt-pyroxenites described by Pearson and coworkers for Beni Bousera. As mentioned above for TAK3 sample, the Morocco pyroxenites differ from Ronda and Beni Bousera pyroxenites for their enrichment in LREE. The group 3 pyroxenites show, in comparison with the group A pyroxenites of Ronda [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF], an enrichment in LILE, Nb and Ta (Fig. 3.14), whereas the patterns are similar as for the remaining trace elements. In particular, Grt-websterite TAK8 shows a positive U anomaly coupled with marked negative Nb and Ta anomalies. The patterns of TAK5, TAK6 and TAK9 samples are characterized by positive Ba anomalies (below 100xC1), associated with negative Nb and Ta anomalies. Grt-websterite TAK6 and TAK8 are also characterized by positive Sr anomalies, whereas TAK5 sample shows negative Sr anomalies.

The last group is represented by three Ol-websterite (TAK7, TAK13 and TAK17) and one Grt-bearing clinopyroxenite (TAK4). In comparison with the third group, these pyroxenites are very depleted in HREE (around 2.5 x C1; Gd N /Lu N = 0.95; Fig. 3.15). TAK4, TAK13 and TAK17 samples show significant positive Eu anomalies. The group 4 pyroxenites are markedly different in the LREE. In particular, Ol-websterite TAK7 and Grt-bearing pyroxenite TAK4 show a marked enrichment (La > 35xC1), whereas Ol-websterite TAK13 and TAK17 shows a hump at Ce and Nd. Similar patterns of MREE and HREE associated with positive Eu anomalies have been described by [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF] for the group B pyroxenites of Ronda and by Pearson et al. (1999) for the Grt-websterites of Beni Bousera. The trace element patterns of Morocco pyroxenites differ from those reported for comparative purpose for the relatively higher LREE contents. The patterns of the other trace elements show a marked positive Ba anomaly associated with depletion in Nb concentrations (Fig. 3.16). Moreover, the samples TAK4, TAK13 and TAK17 are characterized by marked positive Sr anomalies. Quite apart from the lower concentrations, this pattern is similar to those described by Garrido & Bodinier for the Ronda group B pyroxenite. According to [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF], the group B pyroxenites of Ronda represent old mafic layers that were replaced by later magmatic events.

CHAPTER 4 -MAJOR ELEMENT MINERAL CHEMISTRY

The major element analyses of mineral (olivine, clinopyroxene, orthopyroxene, spinel, amphibole and garnet) of both peridotite and pyroxenite samples were carried out at the Dipartimento di Scienze della Terra, Università di Milano with a JEOL 8200 Super Probe, in wavelength-dispersive mode.

All the selected minerals do not show compositional zoning. In general and when possible, the mineral composition was determined both on the porphyroclast and the neoblast grains.

Selected literature data are reported in the covariation diagrams for comparative purposes. In the diagrams for peridotite samples the fields of Middle Atlas lherzolites and harzburgites (Morocco; [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] and of Ronda lherzolites (Southern Spain: [START_REF] Lenoir | The recrystallization front of the Ronda peridotite: evidence of melting and thermal erosion of subcontinental lithospheric mantle baneath the Alboran Basin[END_REF] are reported. Instead, the pyroxenite samples are shown in the graphs according to the four groups detected on the basis of the different bulk rock REE patterns (see table 4.1 and §3.2.2). In the graphs for pyroxenite samples the fields of Middle Atlas (Morocco) pyroxenites investigated by [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF] and [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] are reported, along with literature data for Beni Bousera (Morocco; [START_REF] Kornprobst | Corundum-bearing garnet clinopyroxenites at Beni Bousera (Morocco): original plagioclase-rich gabbros recrystallised at depth within the mantle)[END_REF], Ronda (Southern Spain; [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF][START_REF] Bodinier | Origin of pyroxenite-peridotite veined mantle by refertilization reactions: evidence from the Ronda peridotite (Southern Spain)[END_REF] and Northern Appenine (Italy; [START_REF] Montanini | Exhumation history of a garnet pyroxenite-bearing mantle section from a Continent-Ocean transition (Northern Apennine ophiolites, Italy)[END_REF] pyroxenites. In the garnet classification diagram, the garnet data of Kaapavaal craton (South Africa; [START_REF] Zhang | Mixed mantle provenance: diverse garnet compositions in polymict peridotites, Kaapvaal craton, South Africa[END_REF]

-OLIVINE

-Peridotites

Single olivine grains within a sample show homogeneous chemical composition (Table 1, Appendix B), without differences from porphyroclasts to neoblasts. Moreover, the olivines from lherzolite and harzburgite samples show similar composition. In general, the forsterite content in lherzolites and harzburgites is comprised between 88 and 91 mol% and between 88 and 89 mol%, respectively. The TiO 2 , MnO and NiO concentrations are low both in lherzolites and harzburgites. TiO 2 contents are up to 0.08 wt%, whereas MnO ranges from 0.02 to 0.42 wt% in lherzolites and from 0.11 to 0.27 wt% in harzburgites. Finally, lherzolite and harzburgite samples have NiO contents ranging from 0.13 to 0.49 wt% and from 0.04 to 0.45 wt%, respectively.

-Pyroxenites

Olivine is present only in 4 pyroxenite samples (TAK7, TAK13, TAK17 and BOU4). No compositional differences are observed in TAK7 and BOU4 samples between porphyroclasts and neoblasts and between core and rim of the olivine grains (see Table 1, Appendix B). In general, the fosterite content ranges from 85 (BOU4 sample) to 89 mol% (TAK7 sample). All the samples are characterized by similar TiO 2 contents, which are, in general, comprised between ppm level and 0.08 wt%. The olivine is also characterized by low contents of MnO (from 0.10 to 0.25 wt%) and NiO (from 0.09 to 0.53 wt%). In particular, NiO shows a positive correlation with fosterite content (Fig. 4.2); the highest NiO value is observed in Ol-websterite TAK7, whereas clinopyroxenite BOU4 has the lower NiO abundances.

-ORTHOPYROXENE

-Peridotites

Single orthopyroxene grains within a sample are homogeneous, without significant differences from porphyroclasts to neoblasts and without core to rim zoning. The orthopyroxenes from lherzolite and harzburgite samples have also similar chemical compositions (see Table 2, Appendix B). In general, the Mg-number of orthopyroxene from lherzolites and harzburgites ranges from 89 to 91 and from 89 to 90, respectively. The orthopyroxene Al 2 O 3 content is comprised between 0.78 and 5.1 wt% for the lherzolite samples and 1.8 to 3.0 wt% for the harzburgite samples. The orthopyroxene CaO contents for the analysed lherzolites and harzburgites range from 0.32 to 0.93 wt% and from 0.58 to 1.7 wt%, respectively. Both the Al 2 O 3 and CaO contents show negative correlation with . All the analysed samples fall in the fields of Morocco lherzolites and harzburgites reported by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF]. The Ronda lherzolites [START_REF] Lenoir | The recrystallization front of the Ronda peridotite: evidence of melting and thermal erosion of subcontinental lithospheric mantle baneath the Alboran Basin[END_REF] show similar CaO contents, but they differ for the low Al 2 O 3 contents, which are similar to those of orthopyroxene from SAI1 sample.

The Cr 2 O 3 content ranges from 0.37 to 0.59 wt% for the lherzolites and from 0.17 to 0.48 wt% for the harzburgites. A positive correlation is observed between the Cr 2 O 3 content and the Mgnumber (Fig. 4.3C). The studied samples fall in the Morocco lherzolite and harzburgite fields [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF], while the Ronda lherzolites described by [START_REF] Lenoir | The recrystallization front of the Ronda peridotite: evidence of melting and thermal erosion of subcontinental lithospheric mantle baneath the Alboran Basin[END_REF] decrease is associated with an Al 2 O 3 increase moving from harzburgites to lherzolites and pyroxenites. However, within each field, a positive correlation between the two considered chemical elements is also observed. These trends could be ascribed to melt-rock interaction processes that the samples variably underwent during their refertilization. The orthopyroxenes from lherzolite and harzburgite samples are characterized by FeO contents ranging from 5.4 to 7.2 wt% and from 6.0 to 7.0 wt%, respectively. Their MgO content is comprised between 31.6 and 33.6 wt% for the lherzolites and between 33.2 and 34.1 wt% for the harzburgites. The studied samples show a negative correlation between FeO and MgO (Fig. 4.5). Moreover, all the samples fall in the Morocco and Ronda peridotite fields described by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] and by [START_REF] Lenoir | The recrystallization front of the Ronda peridotite: evidence of melting and thermal erosion of subcontinental lithospheric mantle baneath the Alboran Basin[END_REF], respectively.

A

Fiure .4.3A -Orthopyroxene Al 2 O 3 content vs Mg# for lherzolite and harzburgite samples. For simple reading, only the cores of the porphyroclasts and neoblasts have been reported.

A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A

-Pyroxenites

Within a sample of pyroxenite, single orthopyroxene grains are characterized by homogeneous chemical composition, without differences from porphyroclasts to neoblasts.

However, there are significant compositional differences between different groups of pyroxenites and, in some cases, within each group (see Table 2, Appendix B).

Pyroxenites from group 3 are characterized by Mg-number values comprised between 88 (TAK12) and 91 (TAK9). Instead, the Al 2 O 3 content of these samples is almost homogeneus, around 5.5 wt% in average (Fig. 4.6A). The Cr 2 O 3 contents range between 0.04 (TAK9) and 0.38 wt% (TAK6; Fig. 4.6B). Moreover, FeO contents of orthopyroxenes from group 3 range from 5.8 (TAK9) to 7.9 wt% (TAK12; Fig. 4.8), with almost homogeneous MgO values (ranging from 30.9 to 32.9 wt%, TAK5 and TAK9, respectively; [START_REF] Blicher-Toft | Lu-Hf isotopes systematics of garnet pyroxenites from Beni Bousera, Morocco: implications for basalt origin[END_REF] and to the Morocco websterites [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF]. The studied pyroxenites are also similar to the pyroxenites from Northern Appenine (Italy) described by Montanini and co-workers and to Moroccan websterite TAK3 described by [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF]

-Comparison between peridotites and pyroxenites

For comparative purpose, figures 4.3A, B and D show the compositional fields of orthopyroxenes compositions for the studied pyroxenites. With respect to peridotite samples, Olwebsterites TAK13 and TAK17 and Grt-bearing websterites TAK5, TAK6, TAK8 and TAK12 have orthopyroxene grains with relatively lower Mg-number and higher FeO values. The orthopyroxenes from these samples, together with the orthopyroxene grains analysed for TAK9 and TAK10 Grt-bearing websterites, are also characterized by values relatively higher in Al 2 O 3 .

The orthopyroxenes from the pyroxenite and peridotite samples show similar Cr 2 O 3 and Cao contents. Finally, orthopyroxenes from Ol-websterite TAK7 are characterized by FeO, Al 2 O 3 and Cr 2 O 3 contents similar to those of the peridotite samples.

-CLINOPYROXENE

-Peridotites

Single clinopyroxene grains within most of the analysed lherzolite samples are homogeneous. Only clinopyroxenes from SAI1 sample and from harzburgite samples show heterogeneous chemical composition (see Table 3, Appendix B). All the analyzed clinopyroxenes are diopside in composition (Fig. 4.10). The Mg-number is comprised between 89 and 91 for the lherzolites and between 89 and 92 for the harzburgites. The harzburgite samples show Al 2 O 3 and CaO contents between 1.3 and 5.6 wt% and from 18.8 to 22.5 wt%, respectively. The lherzolite samples are characterized by Al 2 O 3 values comprised from 2.4 to 7.5 wt% and CaO content ranging from 17.6 to 22.4 wt%. The clinopyroxenes from peridotite samples show negative correlation between their Al 2 O 3 content and the Mg-number (Fig. 4.11A).

Clinopyroxenes from selected lherzolites fall in the fields of the Morocco peridotites [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF], whereas the harzburgites have compositions similar to those described by [START_REF] Lenoir | The recrystallization front of the Ronda peridotite: evidence of melting and thermal erosion of subcontinental lithospheric mantle baneath the Alboran Basin[END_REF] for Ronda lherzolites. A positive correlation is observed in figure 4.11B between CaO and Mg-number. Most of the analyzed clinopyroxenes fall in the fields of Morocco and Ronda peridotites. Figure 4.12 shows a roughly positive correlation between Cr and Al clinopyroxene contents. The clinopyroxenes from harzburgites are characterized by low Al value (from 0.02 to 0.25 apfu) with respect to lherzolite samples (between 0.10 to 0.35 apfu). Instead, the clinopyroxene Cr contents range between 0.01 and 0.05 for the harzburgites and from 0.01 to 0.06 for the lherzolites. Some clinopyroxene grains from harzburgite samples have Cr contents similar to harzburgite IBA26 [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF], whereas most lherzolites have compositions similar to those described by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] and [START_REF] Lenoir | The recrystallization front of the Ronda peridotite: evidence of melting and thermal erosion of subcontinental lithospheric mantle baneath the Alboran Basin[END_REF] for the Morocco and Ronda peridotites, respectively. The Ronda lherzolites are characterized by clinopyroxene grains with higher Cr values. The analysed clinopyroxene have Ti contents ranging between 0.00 and 0.02 apfu for the lherzolites and from 0.00 to 0.01 for the harzburgites. The Na contents of harzburgite and lherzolite clinopyroxene range from 0.02 to 0.04 apfu and from 0.11 to 0.30 apfu, respectively. Al and Na contents of the clinopyroxenes are positively correlated (Figure 3.13A ). In particular, the analysed samples show a wide compositional range in comparison to

B A

-Pyroxenites

Clinopyroxene in pyroxenite samples is diopside (Fig. 4.14), with the exception of TAK7 Ol-websterite (augite). Also in the case of pyroxenites, single clinopyroxene grains are homogeneous in composition at the bulk sample scale. Marked differences are observed between "TAK" and "BOU" samples (see Table 3,Appendix B significantly lower than that of clinopyroxene from BOU4 sample (about 0.04 apfu). Finally, the Si content is relatively constant in all the investigated clinopyroxenes (from 1.8 to 1.9 apfu, Fig.4.18). As for the considered elements, clinopyroxenes from pyroxenite xenoliths are similar in composition with their analogues from Beni Bousera [START_REF] Blicher-Toft | Lu-Hf isotopes systematics of garnet pyroxenites from Beni Bousera, Morocco: implications for basalt origin[END_REF] and Norther Apennines (Montanini et al., 2001;Fig.4.19A, B, C, D and E) pyroxenites. Pyroxenite samples from this study are, moreover, similar to those described by Raffone and co-workers and by [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF] for Morocco area. In particular, the clinopyroxenes from clinopyroxenite TAK4 [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF]

-Comparison between peridotites and pyroxenites

For comparative purposes, in the covariation diagrams for clinopyroxene from peridotite samples (Fig.4.11A and B,Fig.4.12,Fig.4.13A and B) the compositional fields of clinopyroxene grains from pyroxenites are also reported. Concerning the Al, Na, Cr, Ti and CaO contents, the clinopyroxenes from Morocco peridotites and pyroxenites are quite homogeneous. The clinopyroxene grains from pyroxenites are characterized by relatively low Mg-numbers and Cr values (Fig. 4.12). Clinopyroxene from clinopyroxenite BOU4 is characterized by very low Mgnumber with respect to all the other ultramafic samples.

-SPINEL

-Peridotites

Single spinel grains at the hand specimen scale are characterized by homogeneous chemical composition. In contrast, significant compositional differences are observed between the samples (see Table 4, Appendix B). According to the Haggerty (1991) classification (Fig.4.20), most of the spinels analysed in the lherzolite samples are classified as spinel s.s.

Their composition (Cr#, i.e. 100*Cr/Cr+Fe 2+ , ranges between 8 and 22; Mg from 78 to 80) is similar to that described by Raffone and co-workers for spinels from Morocco lherzolites. Spinels from the investigated Morocco pyroxenites also show similar compositions. However, some lherzolite spinels have been classified as Mg-Al chromites because of their higher Crnumber. These chemical compositions (Cr# ranging from 27 to 49; Mg# between 19 and 71) are similar to those of spinel grains from Morocco harzburgite samples [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF].

Finally, spinels from harzburgite samples are similar to those analysed by Raffone and coworkers for the Morocco harzburgites and they have been classified as Mg-Al chromites. The spinels have values of 100*Fe 3+ ranging between almost zero (KAD1) and 18.3 apfu (SAI1). The harzburgite spinels are characterized by 100*Fe 3+ contents of about 10.0 apfu. In general, the correlation between 100*Fe 3+ and Cr-number is positive (Fig. 4.21). The chemical heterogeneity of the spinel grains is also confirmed by figure 4.21. Some lherzolite spinels are similar in composition with their analogues described by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] for Morocco lherzolites; in contrast, other samples contain spinel grains that are more similar in composition to the spinels from Morocco harzburgites by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF].

-Pyroxenites

According to the [START_REF] Haggerty | Oxide mineralogy of the upper mantle[END_REF] classification, all spinels from the pyroxenite samples have been classified as spinel s.s. (Cr# comprised between 2.0 and 11.3; Mg# ranging from 77 to 82; Fig. 3.22, see Table 4, Appendix B). These spinels are similar in composition to the spinels described by [START_REF] Montanini | Exhumation history of a garnet pyroxenite-bearing mantle section from a Continent-Ocean transition (Northern Apennine ophiolites, Italy)[END_REF] for Northern Apennines and by [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF] and [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] for the Morocco pyroxenites. Moreover, the analysed grains are also similar to spinels from the Beni Bousera corundum-free pyroxenites described by [START_REF] Kornprobst | Corundum-bearing garnet clinopyroxenites at Beni Bousera (Morocco): original plagioclase-rich gabbros recrystallised at depth within the mantle)[END_REF].

The spinel grains from Ronda pyroxenites [START_REF] Bodinier | Origin of pyroxenite-peridotite veined mantle by refertilization reactions: evidence from the Ronda peridotite (Southern Spain)[END_REF] and Beni Bousera corundumbearing pyroxenites [START_REF] Kornprobst | Corundum-bearing garnet clinopyroxenites at Beni Bousera (Morocco): original plagioclase-rich gabbros recrystallised at depth within the mantle)[END_REF] have been classified as Mg-Al Chromite due to the higher Cr-numbers.

The spinels in garnet-bearing samples of group 3 are characterized by values of 100*Fe 3+ comprised between almost zero and 9.7, while the values of Cr-number is comprised between 3 (TAK5) and 11 (TAK6). Spinels from group 4 Ol-websterites differ for the Cr-number (about 3 for TAK13 and TAK17 and 9 for TAK7), while the values of 100*Fe 3+ are almost homogeneous (ranging from 4.9 to 8.9 apfu).

In general, the 100*Fe 3+ vs. Cr-number covariation diagram shows a positive correlation for spinel (Fig.4.23). Only spinel grains from Ol-websterites TAK13 and TAK17 deviate from this trend. The pyroxenite spinels are similar to those analysed for Morocco (websterite samples, [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF]pyroxenites TAK3 and TAK4, France, 2006), for Northern Apennines [START_REF] Montanini | Exhumation history of a garnet pyroxenite-bearing mantle section from a Continent-Ocean transition (Northern Apennine ophiolites, Italy)[END_REF] and for Beni Bousera corundum-free pyroxenites [START_REF] Kornprobst | Corundum-bearing garnet clinopyroxenites at Beni Bousera (Morocco): original plagioclase-rich gabbros recrystallised at depth within the mantle)[END_REF]. Pyroxenites from Ronda [START_REF] Bodinier | Origin of pyroxenite-peridotite veined mantle by refertilization reactions: evidence from the Ronda peridotite (Southern Spain)[END_REF], corundum-bearing samples from Beni Bousera [START_REF] Kornprobst | Corundum-bearing garnet clinopyroxenites at Beni Bousera (Morocco): original plagioclase-rich gabbros recrystallised at depth within the mantle)[END_REF] and Morocco Fe-rich wehrlite [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] show Crnumbers and 100*Fe 3+ values significantly higher than the analysed samples.

-GARNET

Garnet is a mineralogical phase present in the pyroxenite samples of group 2, group 3 and only in TAK4 Grt-clinopyroxenite from group 4. Garnet is always associated with kelyphitic rims around spinel; only few cores are preserved (data are reported in Table 5, Appendix B). The classification of the analysed grains is reported in figure 4.24. Pyrope content ranges from 69.9 to 73.9, that of grossularia from 9.0 to 13.4, whereas almandine value is comprised between 14.4 and 17.0. The composition of the analysed grains is very close to that of garnets from corundumfree pyroxenites described by Kornprost et al. (1990) and from Kaapavaal craton [START_REF] Zhang | Mixed mantle provenance: diverse garnet compositions in polymict peridotites, Kaapvaal craton, South Africa[END_REF]. The analyzed grains have Cr# values ranging from 68 to 80. The correlation between Cr# vs 100*Mg/(Mg+Fe 3+ +Ca+Mn) confirms the similarity of garnet from this study with that from Beni Bousera described by . All the analyzed samples are homogeneous in composition, with the exception of TAK6 garnets that are characterized by high Cr-numbers and are similar to garnet from websterite TAK3 [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF]. The garnets are also characterized by homogeneous CaO contents (about 5.2 wt%) and by Cr 2 O 3 contents ranging from 0.17 to 0.72 wt%. The CaO vs Cr 2 O 3 covariation diagram (Fig. 4.25A) confirms that garnets from Grt-bearing websterite TAK6 sample are higher in Cr 2 O 3 with respect to the other analyzed pyroxenites. These Cr 2 O 3 contents are closer to those of Morocco websterite TAK3 [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF].

-AMPHIBOLE

Amphibole is a mineralogical phase observed only in peridotite samples. According to the [START_REF] Leake | Nomenclature of amphiboles. Commision a new mineral names, Interantional mineralogical Association[END_REF] classification, all the analyzed amphibole grains are calcic in composition (Fig. 3.26; data reported in Table 6, Appendix B). Amphibole in lherzolite KAD5 is pargasite. Si content in amphibole is about 6.1 apfu and Mg/(Mg+Fe 2+ ) value about 0.88, without core to rim zoning. Amphibole in lherzolite KAD14 has heterogeneous composition. Some grains are classified as pargasite (Si content about 1.0 apfu and Mg# value about 0.87), whereas other grains are edenite (Si value about 7.2 and Mg# value about 0.88). [START_REF] Leake | Nomenclature of amphiboles. Commision a new mineral names, Interantional mineralogical Association[END_REF].

-GEOTHERMOBAROMETRY

Several geothermometers based on cationic exchange reactions sensitive to the parameter T are available for ultramafic systems. They are based on the Fe-Mg exchange between clinopyroxene and orthopyroxene [START_REF] Wells | Pyroxene thermometry in simple and complex system[END_REF]Wood and Banno, 1993;Brey & Köhler -BKN equation, 1990), on the Ca content in orthopyroxene [START_REF] Brey | Geothermobarometry in four-phase lherzolites II.new thermobarometers, and pratical assesment of existing thermobarometers[END_REF] and on the Al content of clinopyroxene [START_REF] Mercier | Single-pyroxene thermobarometry[END_REF]. This last method, in particular, is also used to determine the P value. However, the [START_REF] Mercier | Single-pyroxene thermobarometry[END_REF] geothermobarometer has strong limitations when applied to samples that have been affected by changes in their chemistry, as it usually occurs when melt-rock interaction overprint chemical composition ruled by sub-solidus reactions. Moreover, it is well known that precise estimates of equilibrium P can be hardly obtained due to the lack of appropriate geobarometers for the spinel facies assemblage. In general, porphyroclastic and neoblastic grains show homogeneous chemical compositions.

Accordingly, they provide the same T and P values, thus indicating chemical equilibrium. Owing to the absence of compositional zoning in most of the considered mineralogical phases, P and T conditions for each sample have been estimated using the average chemical composition of porphyroclasts and neoblast, respectively (table 4.1).

In general, [START_REF] Wells | Pyroxene thermometry in simple and complex system[END_REF] and Brey & Köhler (Ca content in Opx;1990) geothermometers provide relatively lower values compared with [START_REF] Mercier | Single-pyroxene thermobarometry[END_REF] and Brey & Köhler (equation BKN;1990) geothermometers. As for the peridotite samples, the geothermometers of [START_REF] Wells | Pyroxene thermometry in simple and complex system[END_REF], [START_REF] Mercier | Single-pyroxene thermobarometry[END_REF] and Brey & Köhler (equation BKN, 1990) have provided the minimum values for lherzolite KAD1 (ranging from 791 to 810°C) and the maximum values for lherzolite TAK25 (comprised between 1248 and 1316°C). Brey and Köhler (Ca content in Opx;1990) geothermometer also indicates the lower T value for lherzolite KAD1 (794°C), whereas the highest T value is given for lherzolite KAD14 (1060°C). In general, the T values range from 855 to 1117°C for the cores in the case of lherzolite samples. Harzburgite samples are characterized by T values similar to those of lherzolites (about 1110°C in average).

The same geothermometers applied to the peridotites were subsequently applied to the pyroxenite samples. In general, all the adopted methods provide a T values comprise between 918 and 1065°C.

PT values for clinopyroxenite BOU4 were estimated using only the [START_REF] Mercier | Single-pyroxene thermobarometry[END_REF] geothermobarometer. This sample is made only by clinopyroxene and this prevented the application of other geothermometers based on cationic exchange between two mineralogical phases. The clinopyroxenes from BOU4 sample record a T value of 969°C with a P value of 13.7 kbar.

The lherzolite and harzbirgite samples are characterized by similar values of P (range from 16.0 to 21.5 kbar and from 21.1 to 22.8 kbar, respectively). For the pyroxenite samples the P values range from 13.0 to 19.3 kbar The PT diagram (figure 4.25A and B) allows some considerations:

1 -as for the core grains (Fig. 4.25A), most of the lherzolite samples show P values close to the boundary of the Spl-Grt stability field for X Cr = 0.2 [where X Cr = Cr/(Cr+Al)]. It must be noticed, however, that all the analysed samples are characterized by X Cr > 0.2. Lherzolite KAD1

shows PT values that are compatible with the Pl-Spl stability field. Except KAD1 sample, all the other lherzolite samples fall in the PT range described by [START_REF] Raffone | Gli xenoliti ultrafemici dell'Atlante Medio (Marocco Nord-Occidentale): petrologia e geochimica del mantello litosferico in un contest di rifting continentale[END_REF] for the Morocco lherzolites. Harzburgite samples ZYA1 and ZYA2, instead, are characterized by PT values more similar to those of Morocco lherzolites [START_REF] Raffone | Gli xenoliti ultrafemici dell'Atlante Medio (Marocco Nord-Occidentale): petrologia e geochimica del mantello litosferico in un contest di rifting continentale[END_REF].

2 -pyroxenite samples (Fig. 4.25B) show P values compatible with the Spl stability field (X Cr = 0.2). Only Ol-websterite TAK7 is characterised by X Cr > 0.6 and shows higher P values.

T estimates for most of the analysed pyroxenites are in agreement with the values obtained by [START_REF] Raffone | Gli xenoliti ultrafemici dell'Atlante Medio (Marocco Nord-Occidentale): petrologia e geochimica del mantello litosferico in un contest di rifting continentale[END_REF] for the Morocco pyroxenites, whereas P values are lower, with the only exception of Ol-websterite TAK13 and TAK17 that fall in the Morocco field.

B CHAPTER 5 -TRACE ELEMENT CHEMISTRY

The composition of trace elements (REE, LILE and HFSE) in major rock forming minerals from both peridotite and pyroxenite samples has been determined by LA-ICP-MS at the "Istituto di Geoscienze e Georisorse, sezione di Pavia". The analyses were carried out mainly on clinopyroxene, amphibole and, when possible, garnet, which are the three mineralogical phases ruling the trace element budget of the investigated samples. When possible, the analyses were carried out on both the cores and the rims of porphyroclasts and neoblasts. In the case of amphibole from KAD5 lherzolite, the neoblastic grains and the exsolution lamellae associated with the clinopyroxene neoblasts have been also analysed. The trace elements data (in ppm) are reported in Table 7 and shown in REE and incompatibility diagrams after normalisation to the C1 chondrite average abundances (ppm) reported by Anders & Edibara (1992).

Selected literature data are reported for comparative purposes. The peridotite samples were compared with peridotite samples from Middle Atlas [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF]. The pyroxenite samples were compared with the Middle Atlas pyroxenite investigated by [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF] and by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF], along with literature data from Beni Bousera (Morocco; [START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF].

-CLINOPYROXENE

-Peridotites

On the basis of the clinopyroxene REE patterns, the lherzolite samples were divided in three main groups (data are reported in Table 7, Appendix B).

The first group comprises three samples

B A 95

The second group is formed by six Amp-free lherzolites (TAK16, TAK19, KAD15, BOU1, SAI1 and SAI2; REE and incompatible element patterns are reported in figures 5. 2A and B, 5.3A and B, 5.4A and B) and two Amp-bearing lherzolites (KAD5 and KAD14;

-Pyroxenites

The trace element signatures of minerals from various pyroxenites are described on the basis of the four main groups identified on the basis of bulck rock REE patterns (chapter 3). Data are reported in Table 7, The Ba contents are variable from 0.10 to 0.14 ppm for the rims and for the cores, respectively.

Cores and rims also show different Th/U ratios, namely < 1 and > 1, respectively. As a whole, According to the Author, TAK4 pyroxenite sample formed in a mantle domain at pressure of 1-2 GPa during post-collisional magmatism that followed the Panafrican orogenic events in Morocco. Moreover, some Beni Bousera Grt-bearing pyroxenites investigated by [START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF] show positive Eu anomalies (Fig. 5.18B). Pearson and co-workers interpreted these samples as the result of the high-pressure crystallizations from melts produced by melting of subducted oceanic crust.

B

A

In general, the porphyroclasts and the neoblasts of clinopyroxenes from group 3 Grtbearing websterite show homogeneous chemical compositions, without marked differences from cores to rims. The clinopyroxenes from Grt-websterite samples TAK5, TAK6, TAK8, TAK9, TAK10 and TAK12 show convex upward REE patterns, with maximum at Eu N ≤ 10xC1 and LREE enrichment over HREE (LuN ≤ 1; La N /Sm N = 0.80 -9.1; La N /Yb N = 5.3 -72.0; the patterns for REE and other trace elements are reported in figure 5. 12A and B, 5.13A and B, 5.14 A and B). All the analysed samples show positive Eu anomalies, with Eu/Eu* = 1.1 -1.3. TAK8 (Fig. 5.12A), TAK6 and TAK12 (Fig. 5.13A) samples show secondary enrichment in La and Ce (La N = 13.0 -60.0; La N /Ce N = 1.5 -6.9). In comparison, REE patterns for TAK5 clinopyroxenes (Fig. 5.12A) are characterized by La N < 10xC1 and by La N /Ce N ≈ 0.70, La N /Sm N = 0.51 and La N /Yb N = 5.0. These LREE patterns are more similar to those of TAK9 and TAK10 samples (Fig. 5.14A), with only apparent secondary enrichment in La (La N = 6.9 -15.3; La N /Ce N = 1.7 -2.5; La N /Sm N = 0.84 -1.83; La N /Yb N = 5.3 -32.4). These spectra can be interpreted as the result of clinopyroxene segregation from enriched melts, followed by re-equilibration with secondary garnet. In particular, some clinopyroxene porphyroclast cores and rims from TAK6 (Fig. Sr anomalies (Sr/Sr* = 0.88 -2.5) associated with negative Rb anomalies. In general, Th/U is < 1, with the exception of TAK6 sample (Th/U ≈ 1). The Ba contents are variable from 0.09 (TAK9 sample) to 11.5 ppm (TAK8 sample). These patterns are similar to those reported by [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF] for clinopyroxene from Morocco Grt-bearing websterite TAK3 (Fig. 5.17A and B). [START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF].

-AMPHIBOLE

The analysed amphiboles of KAD14 lherzolite sample (Fig. 5.6 A and B) do not show chemical compositional heterogeneity from cores to rims. In the KAD5 sample (Fig. 5.5A and B) both the amphibole neoblasts and the amphibole exsolution lamellae associated with clinopyroxene have homogeneous trace element compositions (data reported in Table 8, Appendix B).

In general, the amphiboles show highly fractionated REE patterns, with variable LREE/HREE fractionation (La N /Sm N = 1.8 -4.4; La N /Yb N = 7.3 -19.4.). The La N /Ce N ratio is < 1 for KAD14 sample and > 1 for KAD15. Amphibole are characterized also by negative Pb and Ti anomalies (Ti/Ti* = 0.46 -0.78). The Th/U ratio is < 1 for KAD5 lherzolite and > 1 for KAD14. Moreover, KAD5 sample shows Zr/Hf ratio < 1 (Zr/Zr* ≈ 0.07 ), wherease KAD14 is characterized by Zr/Hf > 1 (Zr/Zr* ≈ 0.14). Amphibole from KAD5 sample is also characterized by positive Ba anomalies (> 100xC1); in general, the Ba content ranges between 436 (KAD14 sample) and 581 ppm (KAD5 sample). Amphibole from KAD14 sample shows a marked positive Nb anomaly (>100xC1; Nb content ≈ 125.0 ppm). The signature of the REE geochemical signatures between coexisting amphibole and clinopyroxene points to a substantial equilibrium between the two mineralogical phases. The amphibole patterns are similar to those reported by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] for the Morocco type 2 lherzolite and harzburgite samples (Fig. 5.9B and C). Moreover, the analyzed garnet shows U enrichments (0.04 -0.18 ppm), which, however, are not so marked as in the associated clinopyroxene. In general, the garnet REE patterns, with the characteristic HREE enrichments, are mirrored by the low HREE abundances in the associate clinopyroxenes. This feature, along with the similar Ti and Sr contents in the coexisting clinopyroxene, indicates a substantial chemical equilibrium between the two mineralogical phases. Moreover, similar garnet REE patterns are described by [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF] for Morocco Grtbearing websterite TAK3(Fig. 5.17A and B) and by [START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF]Fig.5.18B and C) for the Grt-bearing and Grt-Grph-bearing pyroxenites from Beni Bousera peridotite complex. As previously mentioned, according to Pearson and co-workers the pyroxenite samples would represent the high-pressure crystallization products of melts derived from subducted oceanic crust.

-GARNET

-PARTITION COEFFICIENTS

In this paragraph the distribution of the trace elements (REE, HFSE, LILE and transition elements) between pairs of coexisting minerals is described in order to test equilibrium conditions. Amphibole-clinopyroxene pairs are considered to calculate Amp/Cpx D values for KAD5 and KAD14 lherzolite samples. In the case of Amp-bearing lherzolite KAD5, Amp/Cpx D values are calculated for both amphibole neoblast-clinopyroxene and amphibole exsolution-host pairs. Garnet-clinopyroxene distribution coefficients ( Grt/Cpx D) was calculated for the Grt-bearing websterites TAK6 and TAK8.

-Amphibole-clinopyroxene partition coefficients

The Amp/Cpx D values determined for the two Amp-bearing lherzolites (KAD5 and KAD14) confirm the partitioning behaviour expected between these mineralogical phases. In general, the D values for REE, Hf, Zr U and Th are comprised between 0.81 and 2.9 (Fig. 5.19); Ba, Nb, Ta and Ti show a marked preference (in decreasing order) for amphibole. The Amp/Cpx D Ba ratio ranges from 936 and 4323, with the higher values for lherzolite KAD14, whereas the Amp/Cpx D Nb ratio is comprised between 53.8 and 180, with the higher values observed in KAD5 sample. By contrast, Amp/Cpx D Ta is homogeneous in both the lherzolite samples (≈ 17.6), as it is also the case of Amp/Cpx D Ti (from 4.4 to 5.7 for KAD14 and KAD5, respectively. The D Sr and D Sc are similar in the lherzolite samples: the values are comprised between 1.8 and 2.8 and between 0.69 and 0.81, respectively.

In general, the observed values for the partition coefficients are similar to those obtained experimentally by [START_REF] Zack | A consistent partition coefficient set for clinopyroxene, amphibole and garnet from laser ablation microprobe analysis of garnet pyroxenites from Kakanui, New Zeland[END_REF]Fig.5.19) from pyroxenite samples from Kakanui (New Zealand).

As a whole, the observed partitioning behaviour suggest that in the studied lherzolite samples amphibole and clinopyroxene are in mutual equilibrium.

-Garnet-clinopyroxene partition coefficients

As observed for amphibole-clinopyroxene pairs, also the Grt/Cpx D values determined for the Grt-websterites TAK6 and TAK8 confirm the expected partitioning behaviour between these mineralogical phases (Fig. 5.20). In general the D values for the trace elements are < 1, with the exception of HREE (HREE from 122 to 486 for TAK6 sample and from 37.0 to 62.0 for TAK8 sample). The lower partition coefficients are observed for LREE (from 0.002 to 0.008 for TAK6 and from 0.002 to 0.01 for TAK8), whereas MREE show D values comprised from 0.26 and 1.0 (TAK6 sample) and from 0.33 to 1.5 (TAK8 sample). The HFS elements (in particular Nb, Zr and Ti) show higher affinity for clinopyroxene (D Nb,Zr,Ti < 1). Finally, Th and U also show a preference for clinopyroxene. Similar values of partition trace element coefficients have been obtained also for two other Moroccan Fig.5.21).

In general, similar D LREE and D MREE are reported in literature [START_REF] Hauri | Experimental and natural partitioning of the Th, U, Pb and other trace elements between garnet, clinopyroxene and basaltic melts[END_REF][START_REF] Zack | A consistent partition coefficient set for clinopyroxene, amphibole and garnet from laser ablation microprobe analysis of garnet pyroxenites from Kakanui, New Zeland[END_REF][START_REF] Johnson | Experimental determination of partition coefficients for rare earth and high-field-strength elements between clinopyroxene, garnet, and basaltic melt at high pressures[END_REF]Fig.5.20). In comparison with literature data, the Moroccan pyroxenites are characterized by higher D HREE . Similar D Zr values are reported by Zack et al.

118

(1997) for the high-alumina basalts from Medicine Lake (California), whereas [START_REF] Hauri | Experimental and natural partitioning of the Th, U, Pb and other trace elements between garnet, clinopyroxene and basaltic melts[END_REF] and Johnson (1998) calculated higher D Zr for the Kilauea basalts.

As a whole, the observed partitioning behaviour suggests that in the studied pyroxenite samples garnet and clinopyroxene are in mutual equilibrium. In comparison with the literature data, the garnets from the studied pyroxenites show some enrichment as for the the least incompatible elements.

CHAPTER 6 -RADIOGENIC AND STABLE ISOTOPIC DATA

The isotopic data (both radiogenic Sr-Nd isotopes and stable Li and O isotopes) were determined on the pyroxenite samples described in the previous chapters. All the isotopic analyses were carried out also for the Middle Atlas pyroxenites described by [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF] i.e. TAK3 Grtbearing websterite and TAK4 Grt-bearing clinopyroxenite) and by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF]i.e. IBA21c Grt-bearing websterite). Moreover, 87 Sr/ 86 Sr and 143 Nd/ 144 Nd isotopic ratios were determined for the Amp-free lherzolite samples investigated for bulk rock chemistry (KAD1, 2003-1 and HEBRI3 samples).

Sr and Nd compositions were measured at the "Institut Universitaire Européen de la Mer (IUEM) -Domaines Océanique", Brest (France), on clinopyroxene (pyroxenite and lherzolite samples) and garnet (TAK3 and TAK4 samples) mineral separates using a Thermo-electron TRITON T1. Selected samples were crushed using a stainless-steel mortar and pestle, sieved and split into coarse (> 500 mm grain size), medium (500 -250 mm) and fine (< 250 mm) fractions.

Then, the grains not yet separated in the different mineralogical phases were washed in pure water.

Finally clinopyroxenes from the coarse fraction and the garnets from the medium fraction were hand-picked under a binocular microprobe. Around 0.15 mg were taken for analysis. Prior to analysis, the mineral separates were acid-leached with 6N HCl for 60 minutes at 85°C. Leached clinopyroxenes and garnets underwent acid digestion with a mixture of HF-HClO 4 at 150°C (P = 300bar), to prevent the formation of Ca fluorides which trap REE. Drying of the samples was made at the same temperature until the complete evaporation of HClO 4 . Chemical separation for Sr and REE was performed on cationic DOWEX ® AG50X8 columns. Sr part was kept and further processed on the same columns to efficiently separate Sr from Ca. Nd was further eluted on HDEHP-Teflon columns.

Li isotopes were measured at University of Bristol on 0.06 mg of clinopyroxenes from pyroxenite samples, processed by two stage-stage separation chemistry and analysed by multicollector, inductively coupled plasma mass spectrometry (following the procedure documented in [START_REF] Jeffcoate | Precise/small sample size determinations of Lithium isotopic compositions of geological reference materials and modern seawater by MC-ICP-MS[END_REF].

O composition was measured at the "CNR -Istituto Geoscienze e Georisorse of Pisa" by conventional laser fluorination (Sharp, 1995). The oxygen isotope composition was measured on clinopyroxene and olivine grains. In particular, 1.0 -1.5 mg aliquots of 500 µm olivine and clinopyroxene were taken and laser fluorinated.

-Sr -Nd ISOTOPES

-Peridotites

As mentioned in Chapter 4 ( § 4.1.1), the peridotites were divided in three groups on the basis of the clinopyroxene REE patterns. Despite the diversity REE patterns and the different amount of secondary LREE enrichment, the few analyzed lherzolite samples show homogeneous 87 Sr/ 86 Sr and 143 Nd/ 144 Nd isotopic ratios ( 87 Sr/ 86 Sr = 0.702405 -0.702799; 143 Nd/ 144 Nd = 0.513138 -0.513340; Fig. 6.1, complete data are reported in Table 12, Appendix B). With the exception of 2003-1 sample, which shows a prevailing depleted mid-ocean ridge basalt mantle (DMM) signature, the remaining samples fall in the Mid Ocean Ridge Basalt (MORB) and overlap the composition of the peridotites from Beni Bousera [START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF], Ronda [START_REF] Reisberg | Futher Sr and Nd isotopic results from peridotites of the Ronda Ultramafic Complex[END_REF] and Hoggar [START_REF] Beccaluva | Intracratonic asthenosphere upwelling and lithosphere rejuvenation beneath the Hoggar swell (Algeria): evidence from HIMU metasomatised lherzolite mantle xenoliths[END_REF]2008). Moreover, the analyzed lherzolite show 87 Sr/ 86 Sr and 143 Nd/ 144 Nd values similar to those described by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] As mentioned in text, the Moroccan lherzolites fall in the field of beni Bousera [START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF], Ronda [START_REF] Reisberg | Futher Sr and Nd isotopic results from peridotites of the Ronda Ultramafic Complex[END_REF] and Hoggar [START_REF] Beccaluva | Intracratonic asthenosphere upwelling and lithosphere rejuvenation beneath the Hoggar swell (Algeria): evidence from HIMU metasomatised lherzolite mantle xenoliths[END_REF]2008). End-member mantle components after [START_REF] Zindler | Geochemical geodynamics[END_REF] and Hofmann (1997).

-Pyroxenites

The Moroccan pyroxenites are characterized by almost homogeneous 87 Sr/ 86 Sr and 143 Nd/ 144 Nd isotopic ratios (data reported in Table 12, Appendix B; Fig. 6.2). For convenience, however, the samples will be described according to the division reported in Chapter 3 ( § 3.2.2).

The Grt-free clinopyroxenite BOU4 (group 1) is characterized by 87 Sr/ 86 Sr = 0.703963 and by 143 Nd/ 144 Nd = 0.512840. In particular, the 87 Sr/ 86 Sr isotopic ratio is higher relative to that of the other analyzed pyroxenites. This sample falls in the OIB field and shows a composition very close to those of the Moroccan alkaline lavas [START_REF] El Azzouzi | Evolution of the sources of Moroccan volcanism during the Neogene[END_REF], thus confirming its cumulate origin.

As previously mentioned, both clinopyroxene and garnet separates were analyzed for Grtbearing websterite TAK3 (group 2). The 87 Sr/ 86 Sr and 143 Nd/ 144 Nd isotopic ratios are very similar for both the mineralogical phases (Cpx: 87 Sr/ 86 Sr = 0.703113, 143 Nd/ 144 Nd = 0.513253; Grt: 87 Sr/ 86 Sr = 0.703329; 143 Nd/ 144 Nd = 0.513302), thus confirming that the mineralogical phases are in isotopic equilibrium. The Sr and Nd isotopic composition for TAK3 sample is very close to that reported in literature for MORB.

The Grt-bearing websterites of group 3 (TAK5, TAK6, TAK8, TAK9, TAK10 and TAK12, together with IBA21c sample) are characterized by almost homogeneous 87 Sr/ 86 Sr and 143 Nd/ 144 Nd isotopic ratios ( 87 Sr/ 86 Sr = 0.702739 -0.703342; 143 Nd/ 144 Nd = 0.513050 -0.513086). TAK9 and IBA21c samples differ from the group 3 pyroxenites for the higher 143 Nd/ 144 Nd ratios ( 87 Sr/ 86 Sr = 0.702909 -0.703040; 143 Nd/ 144 Nd = 0.513182 -0.513195). Their higher 143 Nd/ 144 Nd isotopic ratios imply that TAK9 and IBA21c samples fall in the MORB field, very close to the TAK3 sample.

TAK5 sample also falls in the MORB field, whereas the other Grt-bearing websterites of group 3 fall in the OIB field and have Sr and Nd isotopic compositions similar to those described by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] for the Middle Atlas pyroxenites (type 2) and by El [START_REF] El Azzouzi | Evolution of the sources of Moroccan volcanism during the Neogene[END_REF] for the Morocco alkaline lavas.

The pyroxenites of group 4 (i.e TAK7, TAK13 and TAK17 Ol-websterite and TAK4 grtbearing clinopyroxenite) are characterized by different 87 Sr/ 86 Sr and 143 Nd/ 144 Nd isotopic ratios. In particular, TAK7 sample shows a Sr and Nd isotopic composition similar to those of TAK5, TAK9 and IBA21c Grt-bearing pyroxenites and falls in the MORB field ( 87 Sr/ 86 Sr = 0.702981;

143 Nd/ 144 Nd = 0.513070). As previously mentioned, both clinopyroxene and garnet were analyzed for TAK4 Grt-bearing pyroxenite. Whereas in the case of clinopyroxene both 87 Sr/ 86 Sr and 143 Nd/ 144 Nd isotopic ratios were determined, only the 143 Nd/ 144 Nd isotopic ratio is available for garnet ( 143 Nd/ 144 Nd = 0.512865). Clinopyroxenes of TAK4 sample have a Sr and Nd isotopic signature similar to that reported by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] for the Middle Atlas type 2 pyroxenites, which overprint also the field of the Morocco alkaline lavas [START_REF] El Azzouzi | Evolution of the sources of Moroccan volcanism during the Neogene[END_REF]. In comparison with the other samples of group 4, TAK4 is characterized by higher 87 Sr/ 86 Sr values thus falling in the OIB field together with some of the group 3 Grt-bearing pyroxenites ( 87 Sr/ 86 Sr = 0.703166 and 143 Nd/ 144 Nd = 0.512904). Finally, TAK13 and TAK17 Ol-websterite samples have similar Sr and Nd isotopic ratios ( 87 Sr/ 86 Sr ≈ 0.702507; 143 Nd/ 144 Nd ≈ 0.702906) and are closer to the MORB field. In particular, their 87 Sr/ 86 Sr isotopic ratio is lower relative to all the analyzed Middle Atlas pyroxenites.

For comparative purposes, in figure 6.2 the isotopic composition of the investigated samples is reported along with the field of Beni Bousera pyroxenites [START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF]. The latter are characterized by higher 87 Sr/ 86 Sr isotopic ratios, whereas the 143 Nd/ 144 Nd values are almost similar.

Similar high 87 Sr/ 86 Sr values have been described also by [START_REF] Xu | Evidence for crustal components in the mantle and constraints on crustal recycling mechanism: pyroxenite xenolith from Hannuoba, North China[END_REF] for the Hannuoba (North China) Al-bearing and Grt-bearing pyroxenites. As mentioned in Chapter 4 ( §4.1.2), Pearson and co-workers interpreted the Beni Bousera pyroxenites as high-pressure crystallization products of melts derived by melting of subducted oceanic crust. A different origin is proposed by [START_REF] Xu | Evidence for crustal components in the mantle and constraints on crustal recycling mechanism: pyroxenite xenolith from Hannuoba, North China[END_REF] for the Hannuoba (North China) pyroxenites, which are regarded as lithospheric high-pressure crystal segregates from parental melts with crustal components in their source. In particular, the Author describes three different types of pyroxenites (i.e. Al-, Cr-and Grt-bearing pyroxenites) and he suggests two different components involved in their formation, namely suggests a continental crust component (i.e subducted terrigenous sediments or delaminated lower continental crust) for the Al-and Cr-bearing pyroxenites, and subducted oceanic crust (i.e. hydrothermally altered basalts and sedimentary materials) for the source of the melts from which the Grt-pyroxenites crystallized. 123

-O ISOTOPES

The results of the oxygen isotopic analyses of Middle Atlas pyroxenite minerals are given in Table 13 (Appendix B) and shown in figures 6.3 and 6.4. The range of δ 18 O values measured in clinopyroxene separates is very restricted and significant differences within the four groups are not observed (Fig. 6.3). In general, the analyzed samples show δ 18 O values similar to those reported in literature for the mantle (δ 18 O mantle comprised between 5.4 and 6.0‰; [START_REF] Rollinson | Using geochemical data: evaluation, presentation, interpretation[END_REF]. Only few samples (BOU4, TAK3, TAK4 and TAK9) deviate from these mantle values.

Clinopyroxene from granular sample (BOU4 clinopyroxenite; group 1) is characterized by the highest δ 18 O values (6.4‰). A similar δ 18 O value (6.2‰) was obtained for clinopyroxenes from TAK3 pyroxenite (i.e. group 2). The Middle Atlas pyroxenites from group 3 are characterized by δ 18 O values ranging from 5.7 (TAK12) to 6.4‰ (TAK9). Finally, clinopyroxenes from group 4 pyroxenites show δ 18 O values comprised between 5.6 (TAK17) and 6.4‰ (TAK4).

Only for the Ol-bearing samples of group 4 it was possible to determine the δ 18 O values in olivine separates. The olivine grains show similar δ 18 O, ranging from 5.9 to 6.0‰. The fractionation between clinopyroxene and olivine (Fig. 6.4) is positive for TAK7 and TAK13 samples and negative for TAK17. al., 1999) and the Middle Atlas pyroxenites [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF]. End-member mantle components after Zindler &[START_REF] Zindler | Geochemical geodynamics[END_REF][START_REF] Hofmann | Mantle geochemistry: the message from oceanic volcanism[END_REF].

-Li ISOTOPES

-Li isotopic systematic

Lithium, the lightest lithophile element, possesses two stable isotopes, 6 Li (≈ 7.5%) and 7 Li (≈92.5%). These two isotopes have the biggest relative mass difference of any isotope pair, aside from hydrogen-deuterium. The potential for mass-dependent fractionation is, thus, obvious. Unlike the better-established light stable isotope system (for exemple O or C), Li is a trace cation and does not form an integral part of hydrological, atmospheric or biological cycles. Hence, measurements of Li isotopes are likely to provide rather different information than is available from the more commonly used isotope system. As with other stable isotope misuraments, Li isotope ratios are expressed in a delta notion:

δ 7 Li = [( 7 Li/ 6 Li sample ) / ( 7 Li/ 6 Li standard ) -1] * 1000
where the standard is conventionally the National Institute of Standard highly purified Li 2 CO 3 reference material NIST L-SVEC [START_REF] Flesch | A secondary isotopic standard for 6 Li/ 7 Li determinations[END_REF], which has 7 Li/ 6 Li ≈ 12.15 [START_REF] Qi | Calibrated measurements of the isotopic composition and atomic weight of the natural Li isotopic reference material IRMM-016[END_REF].

In the δ 7 Li formulation, more positive values are also isotopically heavier, in keeping with other stable isotope system.

The large range of variations of Li isotopic compositions observed in natural system (≈ 60‰ range in 7 Li/ 6 Li ratios) has generated, during the last two decades, a growing interest in its geochemistry. Recent improvements in the precision of Li isotope misurament have highlighted the potential role of this element in tracing a wide range of planetary processes ranging from solar nucleosynthesis [START_REF] Chaussidon | Li-7/Li-6 and B-11/B.10 variations in chondrules from Semarkona unequilibrated chindrite[END_REF] to hydrothermal activity at mid ocean ridge [START_REF] Chan | Lithium isotopic composition of submarine basalts: implications for the lithium cycle in the oceans[END_REF][START_REF] Chan | A lithium isotope study of hot-spring and metabasalts from midocean ridge hydrothermal systems[END_REF]Seyfried et al., 1998). It has also been suggested that Li isotope systematics of island arc basalts may be used to trace the recycling of subducted crustal material into the mantle (Moriguti & Nakamura, 1998a;[START_REF] Chan | Lithium isotopic composition of Central American Volcanic Arc lavas: implications for modification of subarc mantle by slab-derived fluids[END_REF], 2002a, b Tomascak et al., 2000;[START_REF] Elliot | The terrestrial Li isotope cycle: light-weight constraints on mantle convection[END_REF]. According to Elliott et al. (2004), Li isotopes provide a means to trace the mixing of subducting slab and adjacent mantle wedge back into the convective mantle. Moreover, in comparison with the radiogenic isotopes, the Li isotopes are a better tool to highlight the signature of recycled material. Infact, altough the radiogenic isotopes have long been used to infer the distribution of recycled material, their variations can be interpreted in other ways and are more equivocal. In this context, the study of Li isotopes as tracers of subducted material is of particular importance to understand the origin of the Moroccan pyroxenites. Before the Li data presentation of the mantle pyroxenites ( § 6.3.2), it is worth noting how Li behaves during the subductive processes (Fig. 6.5).

According to Elliott et al. (2004;and references therein), plate tectonics mixes altered oceanic crust, with its heavy Li, back into the mantle. The passage of Li from the surface to the depth is strongly affected by the processes occurring during subduction. In particular, water is lost during subduction, through a series of prograde dehydration reactions as the discendig slab became hotter. As in the near-surface environment, the partition of Li between residual solid and liquid will result in isotopic fractionation. As reported in figure 6.5, fluid is expelled out of the subduction zone as a result of compaction of the sedimentary pile. These fluids that returne to the ocean along the so-called décollament are isotopically heaver than the associate sediments (i.e. δ 7 Li serpentinites ≈ -0.5 to 11). Some of the heavy subducted Li is thus clearly lost to the oceans and shallow wedge, but the amount of Li lost from the slab in these early dehydration processes is estimated to be a minor fraction of the total Li subducted (Chan et al., 2000). A major mass flux at subduction zones is associated with magmatism at the volcanic front. Subduction zone magmas are characterized by some distinctive chemical signatures. For example, arc lavas have elevated concentrations of elements observed to be mobile in aqueous fluids (such as Li), relative to elements that form highly charged ions and have low solubilities in aqueous fluids (i.e. Y), but otherwise behave similarly during magmatic processes. Thus, arc lavas have high Li/Y ratios, which would to be associated with heavy Li fluxed from the subducting slab. Few arc lavas, however, have Li isotopic ratios significantly heavier than MORB [START_REF] Tomascak | The control of lithium budgets in island arcs[END_REF]. This feature implies that little budget of heavy Li that enters in the subduction zones is lost to the surface as a result of arc magmatism. The lack of the associated heavy Li isotopic signature can be related to the relative affinity of Li for mantle phases. Li has an ionic radius comparable to Mg and can occupy the Mg lattice sites available in the mantle. Although apparently preferentially transported by fluids, high-T partitioning experiments show that Li is only moderately compatible in either melt or fluid relative to mantle Figure 6.5 -Cartoon of the Li isotope behaviour in the subduction zone. Sketch indicates transfer of fluids with heavy Li to hydrate the adjacent mantle (hatched). The hydrate mantle is viscously coupled and down-dragged with the complementary, isotopically light, dehydrated oceanic crust. Fluids that traverse into the hotter interior mantle wedge and induce melting have already isotopically equilibrated their Li with the preceding mantle. Thus arc lavas have δ 7 Li comparable to the pristine mantle wedge (from Elliott et al., 2004) phases (Brennan et al., 1998a, b). Thus it is likely that heavy Li initially carried from the slab in aqueous fluids isotopically re-equilibrates with the mantle [START_REF] Tomascak | The control of lithium budgets in island arcs[END_REF]. The heavy Li isotopic signature from the slab is transferred to the cold portion of mantle lying above the slab (see figure 6.5). Evidence for the loss of heavy Li from the subducted oceanic crust itself is found in the extremely light Li isotopic ratios of eclogites (δ 7 Li as low as -11). According to [START_REF] Zack | Extremely light Li in orogenic eclogites: the role of isotope fractionation during dehydration in subducted oceanic crust[END_REF], the loss of Li during prograde metamorphism during subduction is associated with significant isotopic fractionation. Infact, Li in the fluid phase is enriched in the heavy isotope leaving the dehydrated slab isotopically light. If accumulated effects of dehydration are modelled as a Rayleigh distillation process, the final "anhydrous" residue at the end of subduction zone processing can have extremely light Li isotopes ratios. This mechanism can be invoked to account for the very light Li isotope ratios observed in the eclogites (see figure 7.6).

Finally, the effects of subduction thus provide additional interest in the use of Li isotopes as tracers of mantle convection. The deep recycled, dehydrated altered oceanic oceanic crust becomes isotopically light. Meanwhile the cool mantle adjacent to the slab becomes heavy. Thus, there are two imputs to the mantle as a result of subduction that are isotopically distinct from the mantle.

-Li data

The results of Li isotopic analyses of clinopyroxene and olivine are given in Table 13 (Appendix B). Clinopyroxene from Middle Atlas clinopyroxenites shows a wide range of Li contents (Fig. 6.6); they are thus described according to the groups previously reported for Sr and Nd isotopes ( § 6.1.2).

Clinopyroxene grains of BOU4 Grt-free clinopyroxenite (group 1) are characterized by higher δ 7 Li values (+7.313‰) relative to the other Middle Atlas pyroxenites. In contrast, lower δ 7 Li values (-6.316‰) are observed in clinopyroxenes from group 2 (TAK3 Grt-bearing websterite).

Grt-bearing websterites of group 3 are characterized by a wide range of δ 7 Li values for clinopyroxene; they vary from negative (-2.037, TAK6 sample) to positive (+2.692, TAK5) values.

Clinopyroxenes from group 4 pyroxenites are also characterized by a wide range of positive δ 7 Li values, which range from 1.392‰ (TAK7 Ol-websterite) up to 3.338-3.875‰ (TAK4, TAK13 and TAK17 samples)

As previously reported, olivine grains were also analysed for the Ol-websterite samples. The olivine δ 7 Li values for the three analyzed samples (TAK7, TAK13 and TAK17) are quite heterogeneous. Olivine from TAK7 sample is characterized by a positive δ 7 Li value (2.69‰), whereas olivines from TAK13 and TAK17 samples show negative δ 7 Li contents (from -1.69 to -1.73‰). The δ 7 Li values obtained for clinopyroxene and olivine from the Ol-websterite samples indicate that these two mineralogical phases are not in isotopic equilibrium. The δ 7 Li vs. δ 18 O diagram (Fig. 6.7) shows that BOU4 cumulate sample is characterized by the higher δ 7 Li and δ 18 O values and that the other investigated pyroxenites from Middle Atlas lack any correlation between δ 7 Li and δ 18 O. Some of the pyroxenites are characterized by δ 7 Li and δ 18 O values similar to those described by Chan et al. (2002) for the altered MORB, although most of them extend towards lower δ 7 Li.

MANTLE

The studied ultramafic Moroccan xenoliths show a wide heterogeneity as for petrography (chapter 2), and for mineral (chapter 3 and 4) and whole rock (chapter 5) chemistry as well. In particular, the study of clinopyroxene trace element signatures has highlighted that lherzolite samples can be divided in three main groups:

• Group 1: it comprises three samples (2003-1, 2003-2 andHEBRI3), which are characterized by spoon-shaped clinopyroxene REE patterns, with progressive LREE enrichment and an almost flat pattern in the MREE and HREE region.

• Group 2: it is formed by six Amp-free lherzolites (TAK16, TAK19, KAD15, BOU1, SAI1 and SAI2) and two Amp-bearing lherzolites (KAD5 and KAD14); their clinopyroxenes show LREE (≥ 100xC1) and MREE (> 10xC1) enrichment over HREE (≈ 10xC1), thus displaying an overall large REE fractionation.

• Group 3: it is constituted only by KAD1 sample; its clinopyroxene has a depleted LREE pattern (below 10xC1), with almost flat pattern in the MREE and HREE region (about 10xC1).

Clinopyroxenes from harzburgite samples ZYA1 and ZYA2, moreover, are characterized by relative enrichment in LREE and MREE over HREE. These patterns are, however, similar to those described for the group 2 lherzolites. As reported in chapter 4 ( § 4.1.1) the lherzolites from group 1 and 2 can be respectively compared with the type-1 and type-2 lherzolites described by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] and collected as mantle xenoliths enclosed in the Plio-Quaternary alkaline basalts from Bou Ibalrhatene (Middle Atlas, Morocco). The equilibrium temperature and pressure estimates based on the two-pyroxene solvus ( § 3.7) provide additional similarities between the studied samples and the ultramafic xenoliths investigated by Raffone and co-workers. The P-T study showed that both group 1 and 2 lherzolites and harzburgites fall in the mantle domain (P between 1.5 and 2.0 GPa) and that their minerals record T values around 1000°C. These values are comparable with those obtained by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] for the Middle Atlas ultramafic lithologies.

Only KAD1 sample (i.e. group 3) provides P-T values lower than those estimated for the other lherzolites (P around 0.9 GPa and T around 800°C). The Sr-Nd isotopic study carried out on a restricted number of lherzolites, which were selected within the groups 1 and 3, revealed MORBlike and DMM-like isotopic signatures. The isotopic data also confirm the similarity between the group 1 and 3 lherzolites and the type-1 lherzolite samples investigated by Raffone and co-workers.

All these geochemical data confirm the evolutionary scenario for the lithospheric mantle beneath the Middle Atlas proposed by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF]. In general, the Middle Atlas mantle xenoliths underwent variable enrichment in incompatible trace elements as a consequence of the interaction with migrating melts. However, some information about the petrochemical characteristics of the mantle before the metasomatic events can be obtained from textural, mineralogical and geochemical features of the xenoliths from groups 1 and 3. According to Raffone and co-workers the Amp-free lherzolites of groups 1 and 3 come from a very fertile mantle sector.

The lithospheric mantle beneath the Middle Atlas region thus most probably consists of very fertile lherzolites, which are locally intercalated with Ol-websterite and associated with more refractory porphyroclastic to coarse-granular harzburgites. Estimated P values indicate that the fertile sectors of lithospheric mantle probably extend down to 75 km depth (see also [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF].

However, very fertile sectors of litospheric mantle must be also present at shallower depths (≈ 30 km), as suggested by combined information from the clinopyroxene REE pattern of KAD1 lherzolite and its P estimates (≈ 0.9 GPa).

In agreement with data reported by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF], the Amp-free lherzolites of groups 2009), after their accretion to the lithosphere these mantle sectors cooled for a long time before the late Cretaceous upward migration of HIMU-like asthenospheric melts, which imparted a metasomatic overprint to the overlying lithospheric mantle. The metasomatic agents reacted with variously depleted mantle sectors, producing a wide variety of trace element signatures. In this scenario, the Amp-free lherzolites of group 1 and 3 record the chromatographic effects of melts percolation (Raffone et al., 2009 and references therein), whereas the REE patterns of harzburgites, Amp-free and Amp-bearing lherzolites of group 2 require that xenoliths progressively approached chemical equilibrium with the migrating liquid. According to [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF], the clinopyroxene patterns of groups 1 and 3 would represent transient metasomatic zoning with variable enrichment in the most incompatible elements formed by an advancing metasomatic percolation front at an increasing distance from the magma sources. In contrast, the group 2 patterns are related to an advanced stage of metasomatism when progressive reequilibration with the migrating liquid results in a marked enrichment of less incompatible elements.

As a whole, the isotopic signatures of group 2 ultramafic xenoliths document the process of thermo-chemical erosion of the lithosphere. These lherzolite samples have a HIMU fingerprinting, similar to that of the erupted alkaline lavas [START_REF] El Azzouzi | Evolution of the sources of Moroccan volcanism during the Neogene[END_REF]; see Fig. 6.1 and 6.2). This situation is common to other Central Northern Africa volcanic occurrences such as Hoggar (Algeria) and Gharyan (Lybia) and indicates the ubiquitous presence of a common HIMU sublithospheric mantle component [START_REF] Beccaluva | Intracratonic asthenosphere upwelling and lithosphere rejuvenation beneath the Hoggar swell (Algeria): evidence from HIMU metasomatised lherzolite mantle xenoliths[END_REF]2008). The abundance of lherzolites of group 2 (i.e. type-2 according to [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF] relative to group 1 and 3 ultramafics, suggests that wide sectors of the mantle beneath the Middle Atlas consist of rejuvenated lithosphere formed by intra-cratonic upwelling and accretion of asthenospheric material. Raffone and coworkers hypothesised that the limited sampling of older cratonic mantle can be regarded as evidence in favour of small-scale shallow-mantle upwelling, triggered by intraplate tectonic reactivation and rifting of the Pan-African basement [START_REF] Beccaluva | Intracratonic asthenosphere upwelling and lithosphere rejuvenation beneath the Hoggar swell (Algeria): evidence from HIMU metasomatised lherzolite mantle xenoliths[END_REF]2008).

-THE HETEROGENEITY OF PYROXENITE

XENOLITHS

The petrographic study (chapter 2) showed that the Moroccan pyroxenites could be divided in four main lithologies (Grt-free and Grt-bearing clinopyroxenite, Grt-websterite and Olwebsterite), without significant petrographic differences within each group. Despite their petrographic similarities, the pyroxenite samples within each lithological group show marked chemical differences, mainly as for the clinopyroxene REE patterns and the bulk rock (major and trace elements) chemistry. Table 7.1 provides a summary of the main chemical features of the investigated pyroxenites.

In the case of samples analysed for the bulk rock major element chemistry, the mineral mode was estimated by mass balance calculations using the mineral chemistry and the MODAN program [START_REF] Paktunc | MODAN: an interactive computer program for estimating mineral quantities based on bulk composition[END_REF]. Results clearly show that some samples (i.e. TAK3 Grt-websterite and TAK4 Grtclinopyroxenite) are characterized by high garnet content (38% and 52%, respectively), whereas the other Grt-bearing pyroxenites possess significantly lower garnet abundances (around 12-15%).

Moreover, the mode of spinel is also variable. In general, in the Grt-bearing pyroxenites it ranges from 1 to 10%, except for the Grt-websterite TAK5 in which the spinel abundance is about 15%.

The higher garnet contents of TAK3 and TAK4 samples and the higher spinel abundance of TAK5 Grt-websterite provide a mineralogical explanation for the high bulk-rock Al 2 O 3 content described in §5.1.2. As reported in chapter 2 ( § 2.2.5), in all the Grt-bearing pyroxenites garnet is a secondary phase that always surrounds the grains of Al-spinel. The pristine mineral assemblage, i.e. before garnet formation, thus probably consisted of two-pyroxenes plus spinel. For this reason, the pristine mineral mode of these pyroxenites was estimated by mass balance calculations removing garnet and considering only spinel as aluminium-rich phase. The new mode on a garnet-free basis is reported in table 7.1. Noticeably, when recalculated on a Grt-free basis all these pyroxenites are characterized by relatively similar amounts of clinopyroxene, orthopyroxene and spinel.

In contrast, TAK7 Ol-websterite is characterized by a different mineralogical composition relative to TAK13 and TAK17 samples; it shows higher olivine contents (around 27%), which well account for the high whole-rock MgO content described in §5.1.2.

The high bulk rock Al 2 O 3 content and the resulting high garnet and spinel mineral modes, along with the positive Eu anomalies observed in both the bulk rock and the clinopyroxene REE patterns, the radiogenic and stable isotopic signatures of some investigate Middle Atlas pyroxenites indicate that these samples cannot be simply regarded as crystal segregates from melts flowing through conduits in the mantle, as hypothesized for several pyroxenites from various occurrences [START_REF] Irving | Petrology and geochemistry of composite ultramafic xenoliths in alkali basalts and implications for magmatic processes within the mantle[END_REF][START_REF] Bodinier | Petrogenesis of layered pyroxenites from Lherz, Freychinède and Prades ultramafic bodies (Ariège, French Pyrénées)[END_REF][START_REF] Suen | Origins of the mafic and ultramafic rocks in the Ronda peridotite[END_REF].

TAK4 Grt-clinopyroxenite and the Ol-websterites TAK13 and TAK17 require a more complex interpretation to account for the chemical and isotopic signatures summarised above, which would be more easily reconciled with recycling of oceanic crust (altered/fresh gabbros or troctolites). The petrographic and geochemical features described for TAK3 and TAK5 Grtwebsterite and for TAK7 Ol-websterite also do not completely support an origin by simple crystal segregation processes. Rather, these samples may better represent the interaction products between magma and peridotite or older pyroxenite wall-rock, as described by [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF] for some pyroxenite samples of Ronda ultramafic Massif.

The different origin for the Middle Atlas pyroxenites is discussed in the following paragraphs.

-TAK4 Grt-clinopyroxenite: recycling of altered plagioclase-rich cumulate?

As mentioned in previous chapters, TAK4 Grt-clinopyroxenite has been the subject of a preliminary study by [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF]. The petrographic study, coupled with the bulk rock geochemical composition and the mineral chemistry, have led the Author to the conclusion that [START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF]. Moreover, the curvilinear grain boundaries of spinel together with the shape of both plagioclase and orthopyroxene, seem to suggest that these minerals are not the phases produced by the sapphirine+garnet reaction; in fact, they can be more probably regarded as the reacting minerals leading to sapphirine formation. These considerations make the igneous origin of sapphirine questionable and seem more consistent with the hypothesis that all the sapphirine in TAK4 Grt-clinopyroxenite has a metamorphic origin. The previously described petrographic features of this sample are most likely function of a distinctive primary mineral assemblage, from which sapphirine would have originated by subsolidus reactions. The multi-phase inclusion in the clinopyroxene grain can be also described by the reaction reported by Griffin & O'Reilly (1986) for the Delegate xenoliths (New South Wales, Australia). In a Ca-and Al-rich system at high P, the reaction expected is: 8Spinel + 3Anortite + SiO 2 = Diopside + 2CaTs + Sapphirine, where the small amount of SiO 2 required could be provided by the orthopyroxene destabilization. The reactions hypothesized to support a metamorphic origin of sapphirine require that plagioclase was a mineralogical phase in the protolith, as it is the case if the latter was originally an aluminous mafic rock formed at low pressure. In other words, TAK4 Grt-bearing pyroxenite could be the product of solid-state recycling of former oceanic crust, possibly a plagioclase cumulate. The whole-rock chemistry of this sample seems to confirm this interpretation. As reported in Table 7.1, TAK4 sample is characterized by a high bulk rock Al 2 O 3 content associated with a relatively low SiO 2 content. Similar high Al 2 O 3 values are reported by [START_REF] Bach | The geochemical consequences of latestage low-grade alteration of lower ocean crust at the SW Indian Ridge: results from ODP Hole 735 (Leg 176)[END_REF] for altered oceanic rocks collected from the South West Indian Ridge (SWIR; Fig. 7.4). For comparative purposes, the fields of both the altered samples described by [START_REF] Bach | The geochemical consequences of latestage low-grade alteration of lower ocean crust at the SW Indian Ridge: results from ODP Hole 735 (Leg 176)[END_REF] and of the fresh oceanic rocks collected from the SWIR by [START_REF] Coogan | Whole-rock geochemistry of gabbros from the Southwest Indian Ridge: constraints on geochemical fractionations between the upper and lower oceanic crust and magma chamber processe at (very) slow-spreanding ridges[END_REF] have been reported in the bulk-rock Al 2 O 3 vs. SiO 2 diagram. Noticeably, the TAK4 sample falls in the field of the altered MORB. As previously described in chapter 5 ( § 5.1.2; Fig. 5.2A and C), similar high bulk rock Al 2 O 3 values are also reported by [START_REF] Kornprobst | Corundum-bearing garnet clinopyroxenites at Beni Bousera (Morocco): original plagioclase-rich gabbros recrystallised at depth within the mantle)[END_REF] for the Beni Bousera corundum-bearing pyroxenites and by [START_REF] Morishita | High-pressure aluminous mafic rocks from the Ronda peridotite massif, southern Spain: significance of sapphirine-and corundum-bearing mineral assemblages[END_REF] for the Grt-and sapphirine-bearing pyroxenites from Ronda. In particular, [START_REF] Kornprobst | Corundum-bearing garnet clinopyroxenites at Beni Bousera (Morocco): original plagioclase-rich gabbros recrystallised at depth within the mantle)[END_REF] interpreted the corundum-bearing pyroxenites of Beni Bousera as recycled oceanic crust. The Authors suggested that these pyroxenites were equilibrated at P = 22-25 kbar and T = 1300-1350°C. Morishita and co-workers, instead, suggested a plagioclase-rich protolith for the Grt-and sapphirine-bearing pyroxenites of Ronda. In their contribution, however, [START_REF] Morishita | High-pressure aluminous mafic rocks from the Ronda peridotite massif, southern Spain: significance of sapphirine-and corundum-bearing mineral assemblages[END_REF] did not provide any constraint for the conditions under which the protolith of these pyroxenites was formed. On the basis of previous geochemical studies, the Authors assumed that the protolith was an aluminous mafic rock formed at low pressure, i.e. a plagioclase-rich cumulate. . REE signatures could provide useful information concerning the origin of TAK4 pyroxenite.

Its whole-rock REE pattern is characterized by a marked positive Eu anomaly, as it is expected if fractionation or accumulation of plagioclase had occurred in oceanic crust magma chambers. This Eu anomaly is observed also in the clinopyroxene and garnet REE patterns. It is worth noting that TAK4 Grt-clinopyroxenite is the only investigated Middle Atlas pyroxenite that shows garnet positive Eu anomalies (see Chapter 4, § 4.1.2). This geochemical feature, associated with the high garnet mineral mode, the presence of metamorphic sapphirine and the consequently high Al 2 O 3 bulk rock content, strongly supports the hypothesis that the protolith was a plagioclase-rich cumulate. In particular, the high bulk rock Al 2 O 3 content, which is similar to that of altered MORBs, may indicate that the protolith was an altered cumulate rock. As for the lower HREE contents, TAK4 clinopyroxenite better compare with gabbroic rocks from Mid-Atlantic Ridge (Fig. 7.5; [START_REF] Godard | Geochemistry of a long in-situ section of intrusive slow-spread oceanic lithosphere: results from IODP Site U1309 (Atlantis Massif, 30°N Mid-Atlantic-Ridge)[END_REF] relative to the altered gabbros described by [START_REF] Bach | The geochemical consequences of latestage low-grade alteration of lower ocean crust at the SW Indian Ridge: results from ODP Hole 735 (Leg 176)[END_REF] for the SWIR and troctolite samples described by [START_REF] Sanfilippo | The generation of lower crust in (ultra-) slow spreading settings: Insights from the Alpine ophiolites and from Godzilla Megamullion[END_REF] for the Corsica ophiolites. These considerations lead to the conclusion that TAK4 Grt-clinopyroxenite may be interpreted as recycled altered oceanic crust, more likely a plagioclase-rich cumulate (±Cpx). The negative δ 7 Li value of TAK4 sample (about -3.8 ‰) are also in accordance with the hypothesis of a crust-derived origin. [START_REF] Chan | Lithium isotopic composition of submarine basalts: implications for the lithium cycle in the oceans[END_REF] and [START_REF] Brooker | Trace elements and Li isotope systematics in Zabargad peridotites: evidence of ancient subduction processes in the Red Sea mantle[END_REF] showed that similar δ 7 Li values, which are lower than those of MORBs (Fig. 7.6), are typical of altered oceanic crust. The putative liquids in equilibrium with clinopyroxene have been calculated using the set of D values proposed by [START_REF] Skulski | High-pressure experimental trace-element partitioning between clinopyroxene and basaltic melts[END_REF]. The obtained melt spectra (Fig. 7.7) confirm that TAK4 clinopyroxene did not form by simple crystallisation from more common melts flowing through the lithospheric mantle, even considering the secondary LREE-enrichment imparted by host lavas. The composition of calculated liquids seems also difficult to reconcile with rock interaction processes operated by alkaline melts. Only the high secondary enrichment in the LREE region of TAK4 (observed on both the bulk rock and clinopyroxene REE patterns) can be reasonably regarded as a later feature due to the metasomatic event operated by HIMU-like melts during the late Cretaceous (as described in paragraph 7.1). The pristine MORB-like isotopic signature of TAK4 Grt-clinopyroxenite was probably completely overprinted by the metasomatic event that imparted its HIMU-like isotopic signature to this sample ( § 6.1.2). [START_REF] Godard | Geochemistry of a long in-situ section of intrusive slow-spread oceanic lithosphere: results from IODP Site U1309 (Atlantis Massif, 30°N Mid-Atlantic-Ridge)[END_REF] for the gabbroic rocks of the Mid-Atlantic ridge. The patterns of altered gabbros from the SW Indian Ridge [START_REF] Bach | The geochemical consequences of latestage low-grade alteration of lower ocean crust at the SW Indian Ridge: results from ODP Hole 735 (Leg 176)[END_REF] and of troctolite from Corsica ophiolite [START_REF] Sanfilippo | The generation of lower crust in (ultra-) slow spreading settings: Insights from the Alpine ophiolites and from Godzilla Megamullion[END_REF] are also report to comparative purpose.

-TAK13 and TAK17: former Pl-poor cumulate?

The REE patterns of the TAK13 and TAK17 Ol-websterites are characterized by marked posive Eu anomalies, which have been observed in both the bulk rock and the clinopyroxene patterns. As previously mentioned for TAK4 Grt-clinopyroxenite, the positive bulk rock Eu anomaly indicates that accumulation of plagioclase had occurred in oceanic crust magma chambers.

Relative to TAK4 sample (Fig. 7.4), TAK13 and TAK17 Ol-websterites are characterized by low Al 2 O 3 bulk rock contents associated with high SiO 2 values. Figure 7.4 shows that these two pyroxenite samples fall close to the field described by [START_REF] Coogan | Whole-rock geochemistry of gabbros from the Southwest Indian Ridge: constraints on geochemical fractionations between the upper and lower oceanic crust and magma chamber processe at (very) slow-spreanding ridges[END_REF] for the fresh MORBs collected from SWIR. Sr-Nd isotopic compositions of TAK13 and TAK17 samples confirm the similarity between the investigated pyroxenites and the rocks of oceanic crust. Ol-websterites have Sr-Nd isotopic signatures close to those of MORBs, although their Sr ratios are relatively lower relative to those expected for typical MORB compositions (see Chapter 6, § 6.1.2). The REE patterns of calculated liquids in equilibrium with clinopyroxenes from TAK13 and TAK17 samples are shown in figure 7.7. As for TAK4 sample, the obtained composition of putative equilibrium melts do not matches those of more common mantle melts that are expected to percolate the lithospheric mantle. The petrographic and geochemical characteristics summarised in Table 7.1, together with the Sr-Nd isotopic compositions, support the hypothesis that TAK13 and TAK17 Olwebsterite represent former fresh oceanic crust recycled at mantle depth. The lack of garnet, the low Al 2 O 3 bulk rock content and the REE bulk rock patterns (Fig. 7.8) strongly suggest that the protolith was a plagioclase-poor cumulate formed under low-pressure conditions. The low δ 7 Li values of clinopyroxene (average -3.5 ‰), well below typical MORB values, support the hypothesis that the protholiths of these two samples were oceanic crust. It is worth noting that clinopyroxenes and olivines show systematic differences in their average Li concentrations (0.80 and 1.6 ppm, respectively) and mineral by mineral isotopic fractionation, with olivine being characterised by the heaviest Li compositions (δ 7 Li about -1.7 ‰ in average, Fig. 7.6) A similar situation has been described by [START_REF] Aulbach | Origins of non-equilibrium lithium isotopic fractionation in xenolithic peridotite minerals: examples from Tanzania[END_REF] [START_REF] Godard | Geochemistry of a long in-situ section of intrusive slow-spread oceanic lithosphere: results from IODP Site U1309 (Atlantis Massif, 30°N Mid-Atlantic-Ridge)[END_REF] for the gabbroic rocks of the Mid-Atlantic ridge. The patterns of fresh gabbros from SW Indian Ridge (SWIR; [START_REF] Coogan | Whole-rock geochemistry of gabbros from the Southwest Indian Ridge: constraints on geochemical fractionations between the upper and lower oceanic crust and magma chamber processe at (very) slow-spreanding ridges[END_REF] and of troctolite from Corsica ophiolite [START_REF] Sanfilippo | The generation of lower crust in (ultra-) slow spreading settings: Insights from the Alpine ophiolites and from Godzilla Megamullion[END_REF] are also report to comparative purpose.

-TAK3, TAK5 and TAK7: melt-rock interaction products?

As reported in Table 7.1, TAK3 and TAK5 Grt-websterites are characterized by high Al 2 O 3 bulk rock contents, similar to those of TAK4 Grt-clinopyroxenite. However, they lack positive Eu anomalies in whole rock REE spectra thus ruling out the role of plagioclase as cumulus phase in the processes that formed these pyroxenites. This consideration implies that TAK3 and TAK5 Grtwebsterites do not represent recycled oceanic crust. Therefore a different origin must be hypothesised for these two samples.

According to Downes (2007), the majority of pyroxenites are best interpreted as mineral cumulates in the broadest sense. Moreover, [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF] suggested an open system magmatic replacement of pre-existing mantle ultramafic rocks as the origin of several groups of pyroxenites in the Ronda massif. Their hypothesis has not yet been extended to other mantle pyroxenites. According to Downes, this hypothesis is hard to test unless field evidence is available; nevertheless, it may predict variable bulk rock compositions that do not match magma compositions coupled with mantle-like isotopic signatures. As for TAK3 and TAK5 pyroxenites, the high garnet and spinel contents of TAK3 and TAK5 Grt-websterites (comprised between 38 and 15% and between 10 and 15%, respectively) strongly support the hypothesis of [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF] about their origin. Most likely these Grt-pyroxenites were formed by reactions between mantle melt and older mafic layers (most probably older pyroxenites), which were completely replaced by the reaction. The high garnet and spinel mode and the consequently high Al 2 O 3 bulk rock contents of the two investigated Grt-websterites suggest that the older pyroxenites with which the mantle melts reacted mainly consisted of clinopyroxene, spinel and garnet. The compositions of liquids in equilibrium with clinopyroxenes (Fig. 7.9), calculated using D values proposed by [START_REF] Skulski | High-pressure experimental trace-element partitioning between clinopyroxene and basaltic melts[END_REF], also exclude a cumulative origin for TAK3 and TAK5 samples. However, these samples differ as for the whole-rock HREE contents (see Chapter 5, § 5.2.2) and for the δ 7 Li values (see Chapter 6, § 6.3.2). As for the HREE, TAK3 has significantly higher HREE abundances relative to TAK5. A possible interpretation is that TAK3 was a garnet-rich pyroxenite, possibly formed in the garnet stability field. The HREE enrichment was thus preserved in spite of repeated melt interaction processes, the last of which were operated by host alkaline melts. In contrast, TAK5 sample, in virtue of its lower garnet abundances and HREE enrichment, either formed under spinel facies conditions or progressively lost its original trace element (and particularly HREE) fingerprinting in response to reaction and successive partial equilibrium with various percolating melts as previously described ( § 7.1). The Sr-Nd isotopic signatures of TAK3 and TAK5 indicate that the source of mantle melts was most probably MORB in composition (see Chapter 6, § 6.1.2). As it is the case of TAK4 sample, the LREE enrichment observed in TAK3 is late feature related to the reaction with HIMU-like percolating melts before the xenolith entrapment in host lavas. Regarding the different δ 7 Li values, TAK3 pyroxenites show a negative value (-6.3‰), while clinopyroxenes from TAK5 sample are characterized by a positive value (about +2.7‰). The negative δ 7 Li values of TAK3 strongly support the involvement of a crustal component in the origin of this sample.

Based on petrographic and geochemical features, also the origin of TAK7 Ol-websterite cannot be described by a simple process of crystal accumulation from mantle melts. Also the recycling of oceanic crust previously suggests for some Moroccan pyroxenite (TAK4, TAK13 and TAK17) must be excluded due to the lack of evidence (i.e. Eu anomalies) in favour of former plagioclase that characterizes the crust-derived materials. It is worth noting that the clinopyroxene REE pattern (the main characteristics are reported in Table 7.1; for more details see Chapter 4, § 4.1.2) is similar to those described for the clinopyroxene grains of the Moroccan lherzolites of the first group (Chapter 4, § 4.1.1). This similarity, associated with the higher bulk rock MgO content, lead to hypothesize a melt-rock interaction origin for this sample, such as an open system magmatic replacement of pre-existing mantle ultramafic rocks. In particular, TAK7 mineral mode (i.e. high orthopyroxene and olivine mineral percentages, coupled with low clinopyroxene content and subordinate spinel) implies that the ultramafic protolith was a mantle peridotite, probably harzburgite in composition. On this framework, the Sr-Nd isotopic signatures of TAK7 Olwebsterite may suggest that either the melts interacting with host peridotite were MORB in composition, or that the overall MORB signature resulted from a mixing of DMM-like signatures with alkaline (i.e. OIB-like) agents. The limited LREE enrichment of TAK7 clinopyroxenes relative to bulk sample suggests a relatively recent chemical overprint by alkaline melts similar to the host lavas.

As previously described for TAK13 and TAK17 Ol-websterites, the Li isotope composition indicates non-equilibrium between the olivine and the clinopyroxene grains of TAK7 samples. Also in this case, the highest δ 7 Li contents are recorded in the olivine grains, while the clinopyroxenes are characterized by relatively low δ 7 Li values. These features are similar to those previously described for TAK13 and TAK17 Ol-websterite and are compatible with the processes of kinetic Li diffusivities described by [START_REF] Aulbach | Origins of non-equilibrium lithium isotopic fractionation in xenolithic peridotite minerals: examples from Tanzania[END_REF].

-Other Moroccan pyroxenites: crystal cumulation origin

The remaining investigated Grt-websterites (i.e. TAK6, TAK7, TAK8, TAK9, TAK10, TAK12 and IBA21c) show approximately the same petrographic and geochemical characteristics.

As reported in Table 7.1, the mineral mode, the whole-rock and mineral chemistry do not show significant differences. However, these Grt-websterites are different from those previously described. The low garnet content (about 5% in average) associated with the low Al 2 O 3 bulk rock content (Fig. 7.4) and the lack of Eu anomalies implicate that these samples do not represent recycled oceanic crust or the products of magmatic replacement of pre-existing ultramafic rocks.

These pyroxenites are better interpreted as the result of magmatic crystallization in mantle conditions from enriched melts. After their formation in the spinel stability field, the pyroxenites reequilibrated in the garnet stability field thus forming the Grt-websterites. This scenario is strongly supported by the presence of spinel grains surrounded by garnet together with the clinopyroxene REE patterns of some samples (TAK6, TAK12 and IBA21c; Chapter 4, § 4.1.2), which still record the pristine chemical signature before garnet exsolution. As described in Chapter 2, the porphyroclastic clinopyroxenes are characterized by garnet exsolutions, which are rare in the clinopyroxene grains. Similar exsolution have been described by [START_REF] Kornprobst | Le massif ultrabasiques de Beni-Buchera (Rif Interne, Maroc): etude des péridotites de haute temperature et des pression et des pyroxénolites à grenat et sans grenat qui leur sont associées[END_REF] in pyroxenites from Beni Bousera ultramafic massif (Morocco) and have been interpreted as the result of destabilization of Tschermack molecules in pyroxenes structures (mainly clinopyroxene) after temperature drop. Accordingly, destabilized Al-rich clinopyroxenes produced Al-poor clinopyroxene and garnet. The wide range of δ 7 Li values (comprised between -2.03 and +2.69 ‰) is probably ascribed to the high Li diffusion.

As described in previous chapters, BOU4 clinopyroxenite clearly shows cumulate features.

The petrographic characteristics together with all the geochemical data confirm that BOU4 clinopyroxenite crystallized from alkaline melts carrying HIMU components. Relative to the other investigated Marocco pyroxenites, BOU4 clinopyroxenite is characterized by the higher 87 Sr/ 86 Sr isotopic ratio and has HIMU-like signatures (see Chapter 6). The Sr-Nd isotopic composition of BOU4 sample is, moreover, closer to the field of Moroccan alkaline lava described by El Azzouzi et al. (1999). The δ 7 Li value of about +7.31‰ also confirms the HIMU component according to [START_REF] Halama | The Li isotopic composition of Oldoinyo Lengai: Nature of the mantle surces and lack of isotopic fractionation during carbonatite petrogenesis[END_REF]and references therein).

Further evidence for possible magmatic crystallization of all these samples is provided by the REE patterns of putative liquids in equilibrium with clinopyroxene (D values after [START_REF] Skulski | High-pressure experimental trace-element partitioning between clinopyroxene and basaltic melts[END_REF]Fig.7.10), which closely approach those of more common enriched melts flowing through the lithospheric mantle.

CHAPTER 8 -CONCLUSION

The study of peridotite xenoliths brought to the surface by alkaline basaltic melts in the Azrou Timahdite volcanic district (Middle Atlas, Morocco) has revealed extreme lithological and chemical heterogeneity in the lithospheric mantle beneath the NE-SW volcanic alignment parallel to the Trans-Moroccan fault system. Most of the investigated xenoliths are lherzolites, with subordinate harzburgites and pyroxenites. In particular, this Ph.D. Thesis was mainly focused on the pyroxenite rocks in order to understand whether these rocks represent magmatic events and/or sectors of subducted crust recycled in the lithospheric mantle. The study was also aimed at characterizing the composition and the geodynamic evolution of the North-Africa lithospheric mantle.

The geochemical data (major and trace elements, bulk rock composition and Sr-Nd isotopic signature) of lherzolite and harzburgite samples confirmed the evolutionary scenario for the lithospheric mantle beneath the Middle Atlas proposed by [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF]. Only few samples still record old melt-extraction processes, documented by DMM-or MORB-like isotopic signatures.

After their accretion to the lithosphere, these mantle sectors were exhumed (during late Cretaceous times) by asthenospheric melts with HIMU-like isotopic signatures. These melts caused a strong metasomatic overprint in the lithospheric mantle. Accordingly, some lherzolite and harzburgite samples record the chromatographic effects of melt percolation (group 1 and group 3 samples), whereas other xenoliths (group 2 samples) progressively approached chemical equilibrium with the migrating melts and were extensively re-fertilized. This heterogeneity possibly resulted from the difference location of samples with respect to the melt percolation front. Relative to group 2 samples, group 1 and group 3 samples were located far from the melt sources. It is worth to note that the lithosphere beneath the Middle Atlas record a long process of thermo-chemical erosion, also document by the isotopic signatures of the xenoliths. With the exception of subordinate lherzolites, that have DMM-like isotopic affinity, the great majority of the xenoliths have a clear HIMU fingerprinting, similar to that of the erupted alkaline lavas.

The geochemical data (major and trace elements, bulk rock composition, Sr-Nd isotopic signature, Li and O isotopic fingerprint) revealed that Middle Atlas pyroxenites have arisen due to different processes:

• TAK4 Grt-clinopyroxenite represents the product of recycling of older oceanic crust.

In particular, the high Al 2 O 3 bulk rock content, the positive Eu anomaly described for both the whole rock and the mineralogical phases (clinopyroxene and garnet), the high garnet percentage and the presence of sapphirine strongly support the hypothesis that the protolith was a plagioclase-rich cumulate, i.e. plagioclase-rich troctolite. Similar high Al 2 O 3 bulk rock contents were reported by [START_REF] Bach | The geochemical consequences of latestage low-grade alteration of lower ocean crust at the SW Indian Ridge: results from ODP Hole 735 (Leg 176)[END_REF] for the altered gabbros from the South-Western Indian Ridge (SWIR). For this reason, it is not excluded that the protolith was an altered plagioclase-rich cumulate.

• TAK13 and TAK17 Ol-websterites also represent recycled oceanic crust. The marked positive Eu anomalies (described both for the bulk rock and for the clinopyroxenes REE patterns) strongly support this hypothesis. The low Al 2 O 3 bulk rock content, similar to that reported by [START_REF] Coogan | Whole-rock geochemistry of gabbros from the Southwest Indian Ridge: constraints on geochemical fractionations between the upper and lower oceanic crust and magma chamber processe at (very) slow-spreanding ridges[END_REF] for the fresh gabbros of SWIR, suggests that the protolith was a Pl-poor cumulate (i.e. Ol-rich troctolite).

• TAK3 and TAK5 Grt-websterite were, most probably, formed by reactions between mantle melt and older mafic layers (most probably older pyroxenites). The lack of positive Eu anomalies (i.e. the evidence in favour of former plagioclase) seems to rule out an origin as recycled oceanic crust. On the other hand, the high garnet and spinel contents associated with the high Al 2 O 3 bulk rock values are incompatible with a simple crystal accumulation processes. These characteristics, therefore, suggest that the older pyroxenites with which the mantle melts reacted were made by clinopyroxene, spinel and garnet. The involvments of a crustal component in the origin of TAK3 sample is suggested by the low δ 7 Li values. The origin of TAK5 sample is more controversial. The high Al 2 O 3 content and similarity of REE spectra with some A-group pyroxenites from Ronda [START_REF] Garrido | Diversity of mafic rocks in the Ronda peridotite: evidence of pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere[END_REF]) favours a melt reacted origin. However, if the high Al 2 O 3 content is disregarded, REE patterns and other incompatible elements and Li isotope as well, do not allow a clear distinction from group 3 pyroxenites.

• TAK7 Ol-websterite shows a clinopyroxene REE pattern similar to those described for the clinopyroxene grains of the Morocco lherzolites of first group. This similarity, associated with the higher bulk rock MgO content, lead to hypothesize also for TAK7 sample an origin due to open system magmatic replacement of preexisting mantle ultramafic rocks. TAK7 mineral mode (i.e. high orthopyroxene and olivine mineral percentages, with low clinopyroxene content and subordinate spinel) implies that the ultramafic protolith was a mantle peridotite, probably harzburgite in composition.

• TAK6, TAK8, TAK9, TAK10, TAK12 and IBA21c Grt-websterites show similar geochemical characteristics. These samples are better interpreted as the result of magmatic crystallization from enriched melts at mantle depth. After their formation in the spinel stability field, pyroxenites re-equilibrated in the garnet stability field thus forming the Grt-websterites.

• BOU4 clinopyroxenite shows cumulate features. The petrographic characteristics together with all the geochemical data confirm that BOU4 clinopyroxenite crystallized from alkaline melts with HIMU component.

An overall geodynamic scenario for the Middle Atlas (northwestern Morocco) is illustrated in figure 8.1, where the lithosphere-asthenosphere interaction processes beneath the area are described in a simplied form. Based on the discussion reported in Charter 7 ( § 7.1), the sectors of rejuvenated lithosphere formed by intra-cratonic upwelling and accretion of asthenospheric material are shown, along with the location of group 1, group 2 and group 3 lherzolite xenoliths. The latter are located at distinct structural levels depending on their relative position with respect to the melt percolation front.

Within this scenario the origin and the age of pyroxenites interpreted as fragments of recycled oceanic crust (TAK4, TAK13 and TAK17) and as products of melt-rock interaction processes (TAK 3 and TAK55) are not completely understood. By analogy with Ronda and Beni The Cpx grains (5%; 1.0 -2.0 mm) have anhedral shape and occupy interstitial position.

The Cpx grains are not deformed and do not show Opx exsolutions lamellae.

The Cr-Spl (5%; 0.25 -3.0 mm) is interstitial compared with others porphyroclasts and it has anhedral shape. Locally, the grains include small rounded Opx grains.

TAK14

The sample is characterized by medium to coarse-grained porphyroclastic texture, with fine-grained neoblastic crystallization of Ol and Opx (±Cpx).

The Ol porphyroclasts (1.6 -2.6 mm) have tabular shape and they show kink-band deformations. The Ol neoblastics (0.01 -1.3 mm), locally weakly deformed, have rounded shape. Total olivine is about 55%.

The porphyroclasts of Opx (2.0 -3.8 mm) have anhedrale shape, with curvilinear grains boundaries occupied by neoblastic crystallization. The porphyroclasts show Cpx exsolution lamellae and kink-band deformations. The neoblasts of Opx (0.25 -0.75) have anhedral shape.

Total orthopyroxene is about 28%.

The grains of Cpx (7%; 0.25 -1.5 mm) have anhedral shape and occupy interstitial position. Locally, the grains of Cpx show Opx exsolution lamellae.

The grains of brownish Spl (10%; 0.02 -1.5 mm) have anhedral shape and are partially replaced by neoblastic crystallization. Cr-Spl is interstitial compared with others grains and shows small inclusion of rounded Ol. The Cr-Spl neoblats have rounded shape.

TAK15

The sample is characterized by medium-to coarse-grained porphyroclastic texture, with wide fine-grained neoblastic crystallization of Ol, Opx, Cpx and Al-Spl. Moreover, the sample reveals a preferential isorientation of the grains. This sample contains scarce melt pockets, which are often associated with Cpx and interstitial with respect to other mineral grains.

The porphyroclasts of Ol (0.75 -1.4 mm) have elongated shape and kink-band deformations. The grain boundaries are curvilinear and show crystallization of neoblastic olivine.

Ol neoblasts (0.02 -0.90 mm) have tabular shape and are undeformed. Total olivine is about 70%.

Opx porphyroclasts (1.5 -4.5 mm) have subhedral to anhedral shape, with curvilinear grain boundaries occupied by neoblasts. Locally, the porphyroclasts include small rounded neoblasts of Ol and are weakly deformed (kink-band deformation). Cpx exsolution lamellae are also present. The neoblasts of Opx (0.01 -0.60 mm) have anhedral shape and are undeformed.

Total orthopyroxene is about 15%.

The grains of Cpx (5%; 0.60 -0.9 mm) are interstitial compared with other minerals.

The Cpx is undeformed and shows Opx exsolution lamellae.

The grains of greenish Al-Spl (10%; 0.25 -2.0 mm) are interstitial in comparison with others grains; locally, they show small inclusion of rounded Ol. The neoblasts of Al-Spl have rounded shape.

TAK16

The sample is characterized by coarse-grained granular texture, with scarce fine-to medium-grained neoblastic crystallization of Ol, Opx and Cpx. The neoblasts locally show mosaic equigranular texture. The sample also shows interstitial melt pockets, which contain small phenocrysts of Ol ± Cpx.

The The Cpx (7%; 0.75 -1.4 mm) is interstitial and shows Al-Spl exsolution lamellae.

The grains of brownish Cr-Spl (Tr.; 1.8 mm) have anhedral shape; they are generally associated with melt pockets and show spongy rims.

TAK18

The sample is characterized by medium-to coarse-grained granular texture, with scarce fine-grained neoblastic crystallization of Ol, Opx, Cpx and Cr-Spl.

The Ol porphyroclasts (1.1 -3.3 mm) have rounded shape and kink-band deformation.

Locally, the porphyroclasts show small inclusions of rounded neoblasts of Opx and Ol. The porphyroclasts of Ol have, locally, curvilinear grain boundaries occupied by neoblastic crystallization. The neoblastic Ol (0.40 -1.6 mm) has rounded shape and is not deformed. Total olvine is about 65%.

Opx porphyroclasts (0.90 -4.4 mm) have subhedral to anhedral shape and show kinkband deformation. Rarely, the Opx porphyroclasts are poikilitic and characterized by small inclusions of rounded Ol. Neoblastic Opx (0.3 -0.90 mm) has anhedral shape and is not deformed. Total orthopyroxene is about 28%.

The grains of Cpx (7%; 0.75 -0.62 mm) have anhedral shape; they are interstitial with respect to other minerals and not deformed.

The grains of brownish Cr-Spl (Tr; 0.30 -2.1 mm) are interstitial relative to others mineral grains. Moreover, in this sample small rounded Cr-Spl occurs associated with neoblastic grains.

TAK19

The sample is characterized by coarse-grained granular texture, with fine-to medium- The grains of Cpx (15%; 0.50 -2.4 mm) are interstitial relative to the porphyroclasts.

They do not show exsolutions.

The grains of Cr-Spl (Tr.; 0.25 -2.5 mm) have anhedral shape, with small inclusion of rounded neoblasts of Ol, Opx and Cpx.

TAK20

The sample is characterized by medium-grained porphyroclastic texture with wide fine- Total orthopyroxene is about 30%.

grained
The grains of Cpx (10%; 0.63 -1.8 mm) are interstitial relative to other minerals. They

show Opx exsolution lamellae and are not deformed.

The grains of brownish Cr-Spl (10%; 0.25 -1.9 mm) show interstitial texture; they may contain inclusions of rounded Opx and Ol. Neoblastic Cr-Spl is always associated with other neoblasts and shows rounded shape.

TAK21

The sample is characterized by coarse-grained granular texture, with low fine-grained neoblastic recrystallization of Ol, Opx, Cpx (± Cr-Spl). The sample displays the contact with the host basalt. Around the grain boundaries, several basaltic veins crystallizing small phenocrysts of ehuedral Pl are present. The grains show spongy rims at the contact with the basalt.

The Ol porphyroclasts (3.0 -4.3 mm) have both rounded and tabular shape. Only few grains are slightly deformed (they show kink-band deformation). Small inclusions of rounded Ol with different optical orientation are also present. Neoblastic Ol (0.35 -2.5 mm) has rounded shape and is not deformed. Total olivine is about 65%.

The Opx porphyroclasts (2.0 -3.0 mm) have subhedral to anhedral shape; locally, small rounded Ol and Cr-Spl inclusions are present. The Opx neoblasts (0.5 -1.3 mm) have anhedral shape. Total orthopyroxene is about 15%.

The grains of Cpx (20%; 0.90 -2.8 mm) have generally anhedral shape and contain Opx exsolutions lamellae.

The grains of Cr-Spl (Tr.; 2.3 mm) are interstitial relative to others grains. Neoblastic Cr-Spl has rounded shape.

TAK22

The sample is characterized by coarse-grained granular texture, with little fine-to medium-grained neoblastic crystallization of Ol, Opx and Cpx. Several melt pockets also occur in interstitial position; the grains of Cpx and Al-Spl in contact with these pockets show spongy rims. Moreover, small phenocrysts of Cpx and Ol crystallise within the melt pockets.

Ol porphyroclasts (1.6 -4.8 mm) have tabular shape; they are locally rounded and are partially replaced by the crystallization of neoblasts. The porphyroclasts show, moreover, kinkband deformation. Sometimes, the Ol is poikilitic and includes small rounded Opx. Neoblastic Ol (0.35 -3.4 mm) has rounded shape and is not deformed. Total olivine is about 50%.

Opx porphyroclasts (0.63 -4.0 mm) have subhedral shape and display ondulate extinction and Cpx exsolution lamellae. Neoblastic Opx (0.35 -1.4 mm) has anhedral shape and is not deformed. Total orthopyroxene is about 20%.

The grains of Cpx (25%; 1.3 -2.3 mm) have anhedral shape and show double exsolution lamellae (Opx associated with Al-Spl). When in contact with the melt pockets, the Cpx is deformed.

The Al-Spl (5%; 0.40 -2.0 mm) occurs in interstitial position and is always associated with the melt pockets.

TAK23

The sample is characterized by medium-to coarse-grained granular texture, with scarce medium-grained neoblastic crystallization of Ol, Opx, Cpx (± Cr-Spl). The neoblasts locally form mosaic equigranular texture. Interstitial melt pockets that contain Ol and Cpx are also present.

Ol porphyroclasts (1.4 -6.1 mm) have tabular shape and show kink-band deformation.

Neoblastic Ol (0.63 -1.0 mm) has rounded shape and is not deformed. Total olivine is about 75%.

Opx porphyroclasts (3.3 -4.8 mm) have subhedral to anhedral shape and are deformed (kink-band deformation and ondulate extinction). Locally, the grains show inclusions of rounded neoblastic Ol. The few neoblasts of Opx (0.50 -1.1 mm) have anhedral shape and are not deformed. Total orthopyroxene is about 13%.

The grains of Cpx (7%; 0.40 -1.4 mm) are interstitial and show exsolution lamellae of Spl.

The Cr-Spl (5%; 0.02 -2.1 mm) occurs in interstitial position; it is always associated with melt pockets, thus showing irregular grain boundaries.

TAK24: Spl-lherzolite

The sample is characterized by coarse-grained porphyroclastic texture, with wide finegrained neoblastic crystallization of Ol, Opx, Cpx and Cr-Spl. The sample displays a foliation due to orientation of the neoblasts. There are interstitial melt pockets and, inside these pockets, some glass crystallizes.

Ol porphyroclasts (1.8 -4.3 mm) have tabular shape with kink-band deformation. The porphyroclasts have been partially replaced by neoblastic crystallization. The neoblasts of Ol (0.02 -1.1 mm) have rounded shape and are not deformed. Total olivine is about 160%.

Opx porphyroclasts (2.5 -6.8 mm) have subhedral to anhedral shape; they are deformed (kink-band and ondulate extinction) and show Cpx exsolution lamellae. The grain boundaries are curvilinear and occupied by neoblast crystallization. Locally, small inclusions of small rounded neoblastic Ol are also present. Neoblastic Opx is subordinate relative to the porphyroclasts; it has rounded shape and is not deformed. Total orthopyroxene is about 25%.

The grains of Cpx (10%; 0.38 -1.0 mm) are interstitial relative to other minerals; they locally show double exsolution lamellae (Opx associated to Spl).

The Cr-Spl (5%; 0.38 -1.5 mm) occurs in interstitial position; the boundaries of the larger grains show crystallization of neoblasts. These grains are poikilitic and show inclusions of rounded Ol neoblasts.

TAK 25: Spl-lherzolite

The sample is characterized by medium-grained porphyroclastic texture, with extended fine-grained neoblastic crystallization of Ol, Opx, Cpx ± Cr-Spl. Small melt pockets interstitially occur in association with Spl and Cpx grains. The sample has a foliated texture with isoriented grains.

Ol porphyroclasts (0.63 -3.9 mm) have tabular shape with presence of kink-band deformation. Ol neoblasts (0.02 -0.75 mm) occur along the grains boundaries; they have rounded shape and are undeformed. Total olivine is about 60%.

Opx porphyroclasts (2.2 -2.6 mm) have anhedral shape, with presence of kink-band deformation and Cpx exsolution lamellae. The neoblasts of Opx (0.25 -0.60 mm) have anhedral shape. Total orthopyroxene is about 20%.

The grains of Cpx (10%; 0.80 -1.6 mm) occupy interstitial position. Cpx does not show inclusions and is weakly deformed (kink-band deformation).

The grains of Cr-Spl (5%; 0.02 -1.8 mm) are interstitial with respect to other minerals and are always associated to melt pockets.

KAD1: Spl-Lherzolite

The sample is characterized by medium-grained porphyroclastic texture, with extensive fine-grained neoblastic crystallization of Ol, Opx, Spl and Cpx. Both the porphyroclasts and the neoblasts show a preferential orientation.

Ol porphyroclasts (1.3 -3.6 mm) have tabular shape. Locally, grains show kink-band deformation and small inclusions of rounded Opx are present. The porphyroclasts of Ol show curvilinear grain boundaries surrounded by neoblasts (0.25 -2.5 mm), which are round shaped and not deformed. Total olivine is about 60%.

Opx porphyroclasts (1.1 -6.9 mm) have anhedral shape and are weakly deformed.

Moreover, some grains are poikilitic and include small rounded neoblasts of Ol. The porphyroclasts of Opx are characterized, moreover, by Cpx and Al-Spl exsolution lamellae. Opx neoblasts (0.63 mm) have anhedral shape and are not deformed. Total orthopyroxene is about

20%.

The Cpx (10%; 1.3 mm) has anhedral shape and shows Opx exsolution lamellae. Some grains are almost completely replaced by neoblastic crystallization.

The Cr-Spl (10%; 0.25 -1.1 mm) occurs in interstitial position and seldom shows small inclusions of rounded Ol neoblasts.

KAD2

The sample is characterized by medium-to coarse-grained porphyroclastic texture, with fine-to medium-grained neoblastic crystallization. The grains (both the porphyroclasts and the neoblasts) show a foliation. Moreover, the neoblasts form mosaic equigranular texture. Finally, several intergranular melt veins cross the sample. The grains of brownish Cr-Spl (5%; 0.75 -3.3 mm) are interstitial compared to other grains and show irregular grain boundaries.

KAD3

The sample is characterized by coarse-grained granular texture, with fine-to mediumgrained neoblastic crystallization of Ol and Cpx (± Opx).

Ol porphyroclasts (2.0 -5.9 mm) have tabular shape with curvilinear grain boundaries occupied by neoblastic crystallization. Kink-band deformation and small inclusions of rounded neoblasts of Ol are also present. The neoblasts of Ol (0.25 -0.63 mm) have rounded shape. Total olivine is about 65%.

Opx porphyroclasts (1.0 -6.5 mm) have anhedral shape, with irregular and curvilinear grain boundaries occupied by neoblastic crystallization. The grains are weakly deformed and without exsolution lamellae. The very few neoblasts of Opx (0.63 mm) have anhedral shape and are not deformed. Total orthopyroxene is about 15%.

Cpx grains (15%; 1.5 mm) have anhedral shape; locally, they occur in interstitial position and are not deformed.

Cr-Spl (5%; 0.25 -1.5 mm) is interstitial in comparison to the other grains.

KAD5: Amp-Lherzolite

The sample is characterized by coarse-grained porphyroclastic texture, with wide finegrained neoblastic crystallization of Ol, Opx, Cpx and Amp (±Cr-Spl). The neoblasts show mosaic equigranular texture.

Ol porphyroclasts (1.9 -5.5 mm) have tabular shape. They show kink-band deformation and curvilinear grain boundaries occupied by neoblastic crystallization. Locally, the porphyroclasts of Ol are poikilitic and include small rounded neoblasts of Ol. Neoblastic Ol (0.02 -1.2 mm) has rounded shape and is not deformed. Total olivine is about 75%.

Opx porphyroclasts (3.7 -7.4 mm) have anhedral shape; they are partially replaced by the neoblasts and show Cpx exsolution lamellae. Moreover, the grains of Opx include small rounded neoblasts of Ol. These small inclusions show spongy rims at the contact with the host porphyroclast. The neoblasts of Opx (0.25 mm) have anhedral shape and are weakly deformed.

Total orthopyroxene is about 10%.

The grains of Cpx (5%; about 1.5 mm in size) occur in interstitial position. They show exsolution lamellae of brown Amp surrounded by Opx.

The grains of brown Amp (7%, 0.23 -1.8 mm) form clusters, which show mosaic equigranular texture.

The grains of brownish Cr-Spl (3%; 0.01 -0.63 mm) are interstitial relative to other grains.

The grains of Cr-Spl are associated with the clusters of brown Amp, by which they are almost completely replaced.

KAD6

The sample is characterized by medium-to coarse-grained granular texture, with scarce neoblastic crystallization of Ol, Opx (±Cpx). Locally, the neoblasts show mosaic equigranular texture. Several interstitial melt pockets, from which opaque minerals, Ol and Px crystallize, are also present.

Ol porphyroclasts (3.75 -7.5 mm) have tabular shape and show a poorly marked kinkband deformation. The neoblasts of Ol (0.38 -1.5 mm) have rounded shape and are not deformed. Total olivine is about 80%.

Opx porphyroclasts (4.5 -8.8 mm) have anhedral shape and show double exsolution lamellae (both Cpx and Al-Spl), which are aligned at 45°one from the other. The neoblasts of Opx (0.63 -1.0 mm) have rounded shape and are not deformed. Total orthopyroxene is about 14%.

Cpx grains (5%; about 3.5 mm) occur in interstitial position and are not deformed.

The grains of brown Amp (1%) are always associated with melt pockets and probably occurred in interstitial position before melting.

KAD7

The sample is characterized by medium-to coarse-grained granular texture, with scarce fine-to medium-grained neoblastic crystallization of Ol, Opx and Cpx. In this sample several melt pockets basaltic veins are also present. The melts pockets occur in interstitial position and contain euhedral crystals of Ol and Cpx.

Ol porphyroclasts (1.6 -6.6 mm) have tabular shape, with poorly marked kink-band deformation. The neoblasts of Ol (about 0.50 mm) have rounded shape and are not deformed.

Both porphyroclasts and neoblasts show spongy rims at the contact with the basaltic veins. Total olivine is about 70%.

Opx porhyroclasts (2.6 -5.5 mm) have anhedral shape and show double exsolution (both Cpx and Spl). Locally, the porphyroclasts show kink-band deformation. The neoblasts of Opx (about 0.63 mm) have rounded shape and are not deformed. The grain boundaries of porphyroclasts and neoblasts are spongy. Total orthopyroxene is about 10%.

The grains of Cpx (15%; 1.1 -2.9 mm) are interstitial relative to the other grains and do not show spongy rims. They are not deformed and show Opx and Al-Spl exsolution lamellae.

The grains of brownish Spl (5%; 0.50 -4.4 mm) occur in interstitial position and are always associated with the melts pockets.

KAD8: Spl-Lherzolite

The sample is characterized by medium-to coarse-grained porphyroclastic texture, with fine-to medium-grained neoblastic crystallization of Ol, Opx, Cpx (±Cr-Spl). Moreover, the sample contains some intergranular melt veins.

Ol porphyroclasts (1.9 -5.8 mm) have tabular shape, with kink-band deformations and curvilinear grain boundaries occupied by neoblasts. Small rounded inclusions of neoblastic Ol and brownish Cr-Spl are also present. The neoblasts of Ol (0.25 -1.1 mm) have rounded shape and are not deformed. Total olivine is about 65%.

Opx porphyroclasts (1.5 -4.8 mm) have subhedral to anhedral shape. They are partially replaced by neobastic crystallization. The grains also show Cpx exsolution lamellae and small inclusions of rounded neoblasts of Ol. The neoblasts of Opx (0.30 -1.10 mm) have anhedral shape and are not deformed. Total orthopyroxene is about 20%.

The grains of Cpx (10%; 1.1 -2.0 mm) occur in interstitial position and show poorly marked Opx exsolution lamellae.

The grains of brownish Cr-Spl (5%; 0.25 -6.3 mm) are interstitial relative to other mineralogical phases. They show small inclusions of rounded neoblasts of Ol.

KAD9

The sample is characterized by medium-to coarse-grained porphyroclastic texture, with wide neoblastic crystallization of Ol, Opx, Cpx and Cr-Spl. The neoblasts show mosaic equigranular texture. The sample shows also several melts pockets, which contain euhedral crystals of Ol, Px and Pl. These melts pockets are interstitial relative to other minerals;

sometimes, the grains in contact with them show spongy rims.

Ol porphyroclasts (2.9 -5.5 mm) have tabular shape and show kink-band deformation.

Moreover, Ol porphyroclasts show irregular grain boundaries with neoblastic crystallization.

Some inclusions of rounded Ol and euhedral Opx are also present. Neoblastic Ol (0.38 -0.75 mm) has generally rounded shape and is not deformed. Total olivine is about 65%.

Opx porphyroclasts (2.4 -8.6 mm) have anhedral shape; locally, they occur in interstitial position and are weakly deformed. Small rounded inclusions of neoblastic Ol and Opx with different orientation are also present. Neoblasts (about 0.30 mm) have anhedral shape and are not deformed. Total orthopyroxene is about 20%.

The Cpx (10%; 1.9 mm) is interstitial relative to the other mineral grains and is not deformed.

Cr-Spl (5%; 0.25 -1.6 mm) occurs either in interstitial position (in this case it is round shaped) or associated with melts pockets (in this case it shows spongy rims).

KAD12

The sample is characterized by medium-grained porphyroclastic texture, with wide finegrained neoblastic crystallization. Locally, the neoblasts show mosaic equigranular texture.

Moreover, the sample reveals foliation due to orientation of the grains; several interstitial melt pockets are also present. All the grains show spongy rims. Finally, the sample shows a millimetric pyroxenitic band consisting of Cpx and Opx.

Pophyroclastic Ol (2.4 -3.4 mm) has tabular shape with kink-band deformation. The grain boundaries are irregular and occupied by neoblastic crystallization. The neoblasts of Ol (0.38 -1.0 mm) have tabular shape and are not deformed. Total olivine is about 68%.

Opx porphyroclasts (about 10.0 mm) have anhedral shape, with Cpx exsolution lamellae irregular grain boundaries. The neoblasts of Opx (0.5 -1.3 mm) have anhedral shape and are not deformed. Total orthopyroxene is about 10%.

The grains of Cpx (15%; 0.63 -1.5 mm) occur in interstitial positions and show double exsolution lamellae (both Opx and Al-Spl), which are at 120°one from the other.

The grains of Cr-Spl (7%; 0.02 -1.75 mm) are interstitial relative to the other mineralogical phases.

KAD14: Amp-Lherzolite

The sample is characterized by medium-to coarse-grained granular texture, with medium-grained neoblastic crystallization. In addition, the sample shows wide melt pockets in which small phenocrysts of Ol and Cpx crystallize, along with minor amounts of opaque minerals. These melts pockets are connected one to the other with intergranular melts veins.

Neoblasts of brown Amp are associated with melt pockets; when in contact with melt veins, both porphyroclasts and neoblasts show spongy rims.

The porphyroclasts of Ol (2.0 -3.5 mm) have tabular shape and show kink-band deformation. The grain boundaries are irregular and show neoblastic recrystallization. The neoblasts of Ol (0.30 -0.75 mm) have rounded shape and are undeformed. Total olivine is about

65%.

The porphyroclasts of Opx (about 2.4 mm in size) have subhedral shape. They show kink-band deformation, but not exsolution. The neoblasts of Opx (about 0.88 mm in size) have rounded shape and are undeformed. Total orthopyroxene is about 23%.

The grains of Cpx (7%; 2.0 -3.0 mm) occur in interstitial position. They are undeformed and locally show Opx exsolution lamellae.

The grains of brown Amp (5%; 1.0 -5.6 mm) have subhedral to anhedral shape and are undeformed.

KAD15: Spl-lherzolite

The sample is characterized by medium-to coarse-grained porphyroclastic texture, with fine-to medium-grained neoblastic crystallization of Ol, Opx and Cpx. The neoblasts show mosaic equigranular texture. Moreover, the sample is characterized by the presence of one melt vein, which contains small phenocrysts of Ol, Pl, Cpx and opaque minerals. Some melts pockets are also interstitial relative to the mineralogical phases. The grains (both porphyroclasts and neoblasts) show spongy rims at the contact with the melts pockets.

Ol porphyroclasts (2.4 -4.7 mm) have tabular shape with curvilinear grain boundaries and are surrounded by neoblasts. The porphyroclasts also show kink-band deformation. The neoblasts of Ol (about 1.25 mm) have rounded shape, sometimes tabular, and are undeformed.

Total olivine is about 65%.

The porphyroclasts of Opx (3.3 -5.5 mm) have anhedral shape, with Cpx exsolution lamellae. They are partially replaced by neoblastic recrystallization. The neoblasts of Opx (about 0.50 mm in size) have rounded shape. Total orthopyroxene is about 20%.

The grains of Cpx (10%; about 1.5 mm) occur in interstitial position and locally show Opx exsolution lamellae.

The grains of brownish Cr-Spl (5%; 0.38 -1.3 mm) are interstitial relative to the other mineralogical phases. The Cr-Spl is associated with melt veins.

HEBRI1

The sample is characterized by coarse-grained granular texture, with scarce fine-to medium-grained neoblastic crystallization of Ol, Opx and Cpx. The neoblasts show mosaic equigranular texture. The interstitial mineralogical phases (i.e. Cpx and Al-Spl) show spongy rims. The sample shows the contact with the host basaltic lava.

Ol porphyroclasts (1.3 -3.6 mm) have tabular shape and kink-band deformation.

Neoblastic Ol (0.38 -1.6 mm) has rounded shape and is locally deformed. Total oliivine is about

50%.

Opx porphyroclasts (2.3 -9.5 mm) have anhedral shape and are deformed (kink-band or undulated extinction). Locally, Cpx exsolution lamellae and small inclusions of rounded neoblastic Ol are present. Neoblastic Opx (0.25 -1.0 mm) has anhedral shape and is undeformed. Total orthopyroxene is about 25%.

Cpx (15%; 0.40 -2.3 mm) occurs in interstitial position and does not show deformation.

The grains also show Al-Spl exsolution lamellae.

The grains of brownish Spl (5%; 1.3 -2.3 mm) are interstitial relative to others mineral grains; sometimes, they show rounded shape.

HEBRI2

The sample is characterized by medium-to coarse-grained granular texture, with fine-to medium-grained neoblastic recrystallization. The neoblasts form mosaic equigranular texture.

Moreover, the sample shows interstitial melt pockets; mineral grains (both porphyroclasts and neoblasts) show spongy rims at the contact with the melt pockets. The grains of brownish Cr-Spl (5%; 0.75 -1.75 mm) are interstitial relative to the other mineralogical phases. The Cr-Spl is always associated with melt pockets.

HEBRI3

The sample is characterized by medium-to coarse-grained granular texture, with finegrained neoblastic crystallization. Moreover, the sample shows interstitial melt pockets with small phenocrysts of Ol and Cpx .

Ol porphyroclasts (4.25 -5.5 mm) have elongated shape, with kink-band deformation and irregular grain boundaries with neoblastic recrystallization. The neoblasts of Ol (0.30 -0-88 mm) have rounded shape. Total olivine is about 60%.

The grains of Opx (17%; 2.8 -7.5 mm) have anhedral shape and, locally, occur in interstitial position. They show spongy rims and Cpx exsolution lamellae.

The grains of Cpx (20%; 1.4 -2.6 mm) are interstitial relative to the other grains. They

show Opx and Al-Spl exsolution. The grains of Cpx are associated with melt pockets and show spongy rims.

The grains of brownish Cr-Spl (3%; about 1.3 mm in size) are interstitial relative to the other mineralogical phases and associated with melt pockets.

2003-1

The sample is characterized by coarse-grained granular texture, with fine-to mediumgrained neoblastic crystallization of Ol, Opx and Cpx. Moreover, the sample shows primary contact with basaltic lava and contain several melt pockets with small phenocrysts of Ol, Cpx and Pl. The melt pockets are connected by intergranular veins. Finally, the sample is weakly altered.

Ol porphyroclasts (2.8 -7.5 mm) have tabular shape and are partially replaced by neoblastic recrystallization. The grains of Ol show kink-band deformation. Neoblastic Ol (about 0.25 mm) has rounded shape and is undeformed. Total olivine is about 65%.

Opx porphyroclasts (1.4 -5.3 mm) have anhedral shape, with curvilinear grain boundaries surrounded by neoblasts. Locally, Opx is poikilitic and includes small rounded neoblasts of Ol. The porphyroclasts show kink-band deformation and double exsolution lamellae (Cpx and Spl). Total orthopyroxene is about 20%.

The grains of Cpx (15%; 0.5 -3.0 mm) are interstitial relative to the porphyroclasts. Cpx also shows Opx and Spl exsolution lamellae.

The grains of brownish Cr-Spl (Tr; about 5.3 mm in size) are interstitial and are associated with melt pockets. Locally, Cr-Spl shows small inclusions of rounded neoblasts of Opx.

2003-2

The sample is characterised by medium-to coarse-grained granular texture, with

2003-3

The sample is characterized by coarse-grained granular texture, with scarce fine-to medium-grained neoblastic recrystallization of Ol, Cpx, Opx ± Cr-Spl.

The porphyroclasts of Ol (1.6 -6.0 mm) have tabular shape and show kink-band deformation. Locally, Ol shows curvilinear grain boundaries with neoblasts. Neoblastic Ol (0.25 -0.50 mm) has rounded shape and is not deformed. Total olivine is about 70%.

The Opx porphyroclasts (4.1 -6.3 mm) have anhedral shape. The porphyroclasts are sometimes partially replaced by neoblasts. The grains are weakly deformed and locally show small inclusions of rounded Ol neoblasts. The neoblasts of Opx (about 0.75 mm in size) have anhedral shape and are undeformed. Total orthopyroxene is about 15%.

The grains of Cpx (15%; about 0.60 -3.0 mm) are interstitial and show Opx and Al-Spl exsolution lamellae.

The grains of brownish Cr-Spl (Tr.; about 1.0 mm in size) are interstitial relative to the other mineralogical phases.

SAI1

The sample is characterized by medium-to coarse-grained porphyroclastic texture, with wide fine-grained neoblastic crystallization. The neoblasts show mosaic equigranular texture.

The sample is also characterized by melt pockets with fresh glass and phenocrysts of Ol, Px and opaque minerals. These melt pockets are interstitial; some Cpx and Opx relics are associated with them. Finally, both porphyroclasts and neoblasts show a foliation.

The porphyroclasts of Ol (1.3 -4.8 mm) have tabular shape and show kink-band deformation. The grains show spongy rims. The neoblasts of Ol (0.38 -1.4 mm) have rounded shape and are undeformed. Total olivine is about 80%.

The few grains of Opx are porphyroclasts only that are always associated with melt pockets. The Opx (5%) shows kink-band deformation.

The grains of Cpx (15%; about 1.6 mm in size) are interstitial relative to the the Ol grains; they locally show spongy rims.

SAI2

The sample is characterized by coarse-grained porphyroclastic texture, with fine-grained neoblastic crystallization. The neoblasts show mosaic equigranular texture. Melt pockets with small phenocrysts of Ol, Cpx and Pl associated with euhedral opaque minerals are commonly observed.

The porphyroclasts of Ol (2.5 -7.5 mm) have tabular shape, with kink-band deformation and curvilinear grain boundaries marked by neoblastic crystallization. The neoblasts of Ol (0.25 -2.13 mm) have rounded shape and are undeformed ted. Total olivine is about 80%.

The porphyroclasts of Opx (7%; about 4.5 mm in size) have anhedral shape. They show spongy rims and Cpx exsolution lamellae.

The grains of Cpx (10%, about 1.1 mm) are interstitial and show spongy rims; exsolutions are not observed.

The grains of brownish Cr-Spl (3%; about 0.25 mm in size) are interstitial relative to the other mineralogical phases and associated with melt pockets.

BOU1

The sample is characterized by medium-to coarse-grained granular texture, with scarce fine-to medium-grained neoblastic crystallization. The neoblasts show mosaic equigranular texture. Interstitial melt pockets that contain small phenocrysts of Ol and Px are observed.

The porphyroclasts of Ol (2.0 -5.1 mm) have tabular shape. The grains of Ol show kinkband deformation and are partially replaced by the neoblasts. The neoblastic Ol (about 0.60 mm) has rounded shape and is undeformed. Total olivine is about 60%.

The poprhyroclasts of Opx (15%; about 4.0 mm) have anhedral shape, with curvilinear grain boundaries marked by the neoblast. Some grains include small rounded Ol neoblasts. The porphyroclasts of Opx are weakly deformed. The neoblasts of Opx (1.0 -3.0 mm) are round shaped and undeformed.

The grains of Cpx (25%; 2.0 -5.3 mm) are interstitial and undeformed, with exsolution lamellae of greenish Spl, but the Cpx is not deformed. They are characterized by spongy rims.

The grains of brownish Spl (Tr.; about 0.30 mm) are interstitial relative to the other mineralogical phases. The Spl is always associated with melt pockets and shows spongy rims.

Some grains of Spl include rounded neoblasts of Ol.

BOU2

The sample is characterized by medium-to coarse-grained granular texture, with scarce fine-to medium-grained neoblastic crystallization. The sample also shows some interstitial melt pockets.

The porphyroclasts of Ol (1.8 -4.8 mm) have tabular shape with kink-band deformation.

The Ol is partially replaced by neoblasts (about 1.1 mm); these latter are undeformed and have rounded shape. Total olivine is about 60%.

The grains of Opx (25%; 1.1 -5.0 mm) are interstitial. The Opx is undeformed and shows local Cpx exolution lamellae. The grains also show spongy rims.

The grains of Cpx (20%; 1.1 -4.9 mm) are interstitial; they do not show deformation or exsolution lamellae and have spongy rims.

Finally, the sample contains accessory amounts (5%) of brownish Spl (0.25 mm in size).

BOU3

The sample is characterized by coarse-grained granular texture, with fine-to mediumgrained neoblastic crystallization. The neoblasts show locally equigranular texture. Several interstitial melt pockets with altered glass and small phenocrysts of Ol, Cpx are observed. Only in one melt pocket Pl occurs; it shows multiple twinning and is about 2.00 mm in size.

The porphyroclasts Ol (2.8 -6.8 mm) have tabular shape, with kink-band deformation.

The grain boundaries are curvilinear and marked by neoblastic crystallization. The neoblasts of Ol (0.01 -0.33 mm) have rounded shape and are undeformed. Total olivine is about 80%.

Opx (15%; about 4.5 mm in size) and Cpx (10%; about 4.1 mm in size) grains are interstitial and not deformed; they show spongy rims.

HARZBURGITES KAD4

The sample is characterized by coarse-grained granular texture, with scarce mediumgrained neoblastic crystallization. The sample is also crossed by a basaltic vein with small phenocrysts of opaque minerals, Ol and Px; when in contact with this vein the mineral grains show spongy rims.

Ol porphyroclasts (1.3 -5.3 mm) have tabular shape, seldom rounded, and show kinkband deformation. The neoblasts of Ol (0.40 -1.0 mm) have rounded shape and are not deformed. Total olivine is about 88%.

Opx (10%; 5.3 -6.5 mm) is interstitial relative to the Ol grains; it is not deformed and

shows Cpx exsolution lamellae.

Cpx grains (2%; about 5.0 mm) occur in interstitial position; they are not deformed and

show Opx exsolution lamellae. Locally, Cpx forms corona-like textures around the Ol porpyroclasts.

KAD10

The sample is characterized by medium-to coarse-grained granular texture, with scarce fine-grained neoblastic crystallization. Locally, the neoblasts show mosaic equigranular texture.

Ol porphyroclasts (2.0 -15.0 mm) have tabular shape and show kink-band deformation.

Some porphyroclasts of Ol are characterized by small inclusion of rounded Cr-Spl. Ol neoblasts have rounded shape and are not deformed. Total olivine is about 80%.

Opx porphyroclasts (4.3 -8.0 mm) have anhedral shape; they are not deformed and show Cpx exsolution lamellae. The neoblasts of Opx (0.63 -1.25 mm) have rounded shape and do not show alteration. Total orthopyroxene is about 80%.

The grains of Cpx (2%; 0.50 -2.5 mm) are interstitial and not deformed.

The Cr-Spl (Tr., rounded shape) is interstitial relative to the Ol and Opx grains.

ZYA1

The The grains of Cpx (3%; 0.50 -5.0 mm) occur in interstitial position and do not show any exsolution lamella. Locally, Cpx grains contain small inclusions of rounded Ol neoblasts.

The grains of Cr-Spl (2%) have holly-leaf shape (they are largely replaced by the crystallization of new mineralogical phases) and are always associated with melt pockets.

ZYA2

The sample is characterized by medium-grained porphyroclastic texture, with finegrained neoblastic recystallization. The neoblasts show mosaic equigranular texture. Wide melt pockets containing euhedral phenocrysts of Ol and Opx also characterize the sample. In these pockets, fresh glass occupies an interstitial position relative to the phenocrysts. Some grains of Ol and Opx are associated with the pockets: they are almost completely replaced by melt and its crystallization products. Finally, all the grains show a foliation.

The porphyroclasts of Ol (about 3.3 mm in size) have tabular shape and they show kinkband deformation. The grains of Ol show irregular boundaries marked by Ol neoblasts. These latter (0.35 mm) have rounded shape and are weakly deformed when in contact with melt pockets. Total olivine is about 70%.

The porphyroclasts of Opx (2.0 -4.6 mm) have anhedral shape. They show kink-band deformation and curvilinear grain boundaries marked by neoblastic crystallization. Neoblastic Opx (0.30 mm) has rounded shape. Total orthopyroxene is about 27%.

The grains of Cpx (3%; 0.50 -1.5 mm) have anhedral shape and do not show any exsolution lamellae.

PYROXENITES TAK5: Grt and Spl-Websterite

The sample is characterized by coarse-grained porphyroclastic texture, with fine-to medium-grained neoblastic crystallization of Cpx and Opx. The Grt is a secondary phase; it Grt (about 0.30 mm in size) is always associated with kelyphite and preserves a fresh core.

TAK6: Grt-and Spl-Websterite

The sample is characterized by medium-grained porphyroclastic texture, with medium-to coarse-grained neoblastic crystallization of Cpx and Opx. Locally, the neoblasts shows mosaic equigranular texture. The sample is cut by a basaltic vein, which contains Cpx relics and small phenocrysts of Cpx. Both porphyroclasts and neoblasts show spongy rims. The Grt is a secondary phases and occurs as corona around Cr-Spl. In this sample, Opx grains occur only as neoblasts (about 0.38 mm in size). They have rounded shape and are not deformed.

The grains of brownish Spl (0.38 -1.38 mm) are interstitial and locally are associated with the melt pockets.

Fresh cores of Grt (about 0.25 mm) surrounded by kelyphite are preserved.

TAK7 Ol-Websterite

The sample is characterized by coarse-grained porphyroclastic texture, with fine-to medium-grained neoblastic crystallization of Cpx, Opx and Ol. The neoblasts also show mosaic equigranular texture. The grain boundaries (both porphyroclasts and neoblasts) show The grains of Al-Spl (about 0.5 mm) are interstitial and associated with melts pockets.

TAK8: Grt-Websterite

The sample has coarse-grained porphyroclastic texture, with wide fine-to mediumgrained neoblastic crystallization of Cpx and Opx. The Grt is a secondary phase, occurring either as corona around the Al-Spl or exsolution lamellae in Cpx.

The porphyroclasts of Cpx (2.63 -12.0 mm) are partially replaced by neoblasts and show double exsolution lamellae (both Opx and Grt completely replaced by kelyphite). Some porphyroclasts are deformed. The neoblasts of Cpx (0.5 -2.0 mm) have rounded shape and are not deformed.

The Opx is exclusively neoblastic (about 0.38 mm in size) and has rounded shape.

The Al-Spl (0.38 -1.38 mm) is interstitial and always surrounded by Grt.

Fresh cores of Grt (about 0.25 mm) surrounded by kelyphite are preserved.

TAK9: Grt-Websterite

The sample is characterized by coarse-grained porphyroclastic texture, with mediumgrained neoblastic crystallization of Cpx and Opx. All the grains (both porphyroclasts and neoblasts) show spongy rims.

The porphyroclasts of Cpx (2.50 -12.5 mm) have anhedral shape and are deformed; they are partially replaced by neoblastic crystallization. They also show Opx and Grt (the latter completely replaced by kelyphite) exsolution lamellae. The neoblasts of Cpx (0.80 -1.30 mm) have rounded shape and are not deformed.

The neoblasts of Opx (about 0.42 mm) have rounded shape and are not deformed.

The Al-Spl (0.34 -1.20 mm) is interstitial relative to the porphyroclasts and it is always surrounded by Grt (±keliphyte).

Fresh cores of Grt (about 0.19 mm) surronded by kelyphite are preserved.

TAK10: Grt-Websterite

The sample is characterized by coarse-grained porphyroclatic texture, with fine-to medium-grained neoblastic crystallization. Both porphyroclasts and neoblasts show spongy rims.

The porphyroclasts of Cpx (2.50 -12.5 mm) have anhedral shape and show curvilinear grain boundary marked by neoblastic crystallization. The porphyroclasts also show Opx, Grt (the latter completely replaced by kelyphite) and few Al-Spl exsolution lamellae. Finally, they show ondulate extinction. The neoblasts of Cpx (0.70 -1.30 mm) have rounded shape and are not deformed.

Opx neoblasts (about 0.40 mm) have rounded shape and are undeformed.

The grains of Spl (0.38 -1.38 mm) are interstitial and always surrounded by Grt ±keliphyte.

Fresh cores of Grt (about 0.19 mm in size) surrounded by kelyphite are preserved.

TAK12: Grt-Websterite

The sample has coarse-grained porphyroclastic texture, with wide fine-grained neoblastic crystallization of Cpx and Opx. Locally, the neoblasts show mosaic equigranular texture. Both porphyroclasts and neoblats are surrounded by kelyphite. Grt is a secondary phase: it forms coronas around Al-Spl or exolution lamellae in Cpx porpyroclasts. Finally, a foliation due to isorientation of the grains is observed.

The porphyroclasts of Cpx (about 6.2 mm) have anhedral shape and are partially replaced by neoblastic crystallization. Sometimes, Cpx is poikilitic and contain neoblasts of Cpx and Opx.

The porphyroclasts show Opx exsolution lamellae. The neoblasts of Cpx (0.25 -1.5 mm) have anhedral shape and are not deformed.

The neoblasts of Opx (1.2 -2.1 mm) have rounded shape; they are undeformed and locally anhedral.

The grains of Al-Spl (about 0.02 mm) are interstitial and always surrounded by kelyphite.

Fresh cores of Grt (about 0.20 mm in size) surronded by kelyphite are preserved.

TAK13: Ol-Websterite

The sample is characterized by medium-grained porphyroclastic texture, with fine-to medium-grained neoblastic crystallizations of Ol, Cpx and Opx. In the sample, the grains of Al-Spl are concetrated in a band.

Cpx porphyroclasts (1.0 -5.8 mm) have anhedral shape and they have been partially

replaced by neoblastic crystallization. The porphyroclasts show double exolution lamellae (both Opx and Al-Spl), which are parallel one to the other. The neoblasts of Cpx (about 1.0 mm in size) have anhedral shape. Total Cpx is 70%.

The Opx neoblasts (Tr.; about 8.5 mm) have rounded shape and it does not show exsolutions.

In this sample, the grains of Ol are only like neoblasts (20%; 0.3 -2.8 mm). They have tabula shape and they are not deformed.

The grains of Al-Spl (10%; 1.3 mm) are interstitial in comparison with others mineralogical phases.

TAK17: Ol-Websterite

The sample is characterized by medium-grained porphyroclastic texture, with fine-to medium-grained neoblastic crystallization of Ol, Opx and Cpx.

The porphyroclasts of Cpx (0.90 -9.5 mm) have subhedral to anhedral shape and show double and parallel exsolution lamellae (both Opx and Al-Spl). Locally, rims of neoblastic Opx are present around the porphyroclasts of Cpx. In general, the grains of porphyroclastic Cpx are partially replaced by neoblasts. The neoblasts of Cpx (about 0.62 mm in size) have rounded shape and do not show exsolution lamellae. Total Cpx is 35%.

The porphyroclasts of Opx (about 2.9 mm in size) have anhedral shape, with irregular and curvilinear grain boundaries marked by neoblastic crystallization. Locally, Opx grains show kink-band deformation and exsolution lamellae of both Cpx and Al-Spl. The neoblasts of Opx (about 0.30 mm in size) have anhedral shape; they are not deformed and locally rounded, and.

Total Opx is 5%.

In this sample, Ol occurs only as neoblasts. They are about 0.25 -5.3 mm in size and have rounded shape, seldom tabular.

The Al-Spl (10%; 0.02 -3.60 mm) occurs in interstitial position relative to the others porphyroclasts.

BOU4: Clinopyroxenite

The sample is characterized by coarse-grained Cpx cumulate texture, with interstitial grains of Ol. The subhedral grains of Cpx (98%; about 9.0 mm) show spongy rims caused by incipient partial melting. Accessory Ol grains (about 2%) have subhedral to anhedral shape and are associated with altered basaltic melt. Few phenocrysts of ehuedral Pl are present within the altered zones. 20031CPXA1B 23-20031CPXA2B 24-20031CPXA3B 27-20031CPXA6B 28-20031CPXA7B 32-20031CPXD1B 33-20031CPXD2B 34-20031CPXD3B 25-20031CPXA4B 26

Appendix B

ZYA1 ZYA1-B-1 ZYA1-B-3 ZYA1-B-2 ZYA1-B-4 ZYA1-F-1 ZYA1-F-2 ZYA1-H-1 ZYA1-H-2 ZYA1-I-1 ZYA1-I-
ZYA1 ZYA1-M-1 ZYA1-M-2 ZYA1-A-5 ZYA1-A-6 ZYA1-B-5 ZYA1-B-7 ZYA1-B-8 ZYA1-C-3 ZYA1-C-4 ZYA1-C-
1 -Olivine (continued) ZYA2 ZYA2-B-1 ZYA2-B-2 ZYA2-C-4 ZYA2-C-5 ZYA2-E-1 ZYA2-E-8 ZYA2-E-2 ZYA2-E-9 ZYA2-E-10 ZYA2-F-
ZYA2 ZYA2-F-4 ZYA2-I-1 ZYA2-I-2 ZYA2-I-3 ZYA2-A-3 ZYA2-A-4 ZYA2-A-5 ZYA2-B-3 ZYA2-C-7 ZYA2-D-
Ol-websterite ZYA2 TAK7 ZYA2-G-5 ZYA2-G-6 ZYA2-G-7 ZYA2-H-1 ZYA2-H-2 ZYA2-H-3 TAK7-M-1 TAK7-M-2 TAK7-N-1 TAK7-N-
TAK7 TAK7-Q-3 TAK7-Q-4 TAK7-D-3 TAK7-E-1 TAK7-F-3 TAK7-G-3 TAK7-O-1 TAK7-Q-X TAK7-E-2 TAK7-F-
TAK19 TAK25 TAK19-D-3 TAK19-D-6 TAK19-G-2 TAK19-H-2 TAK19-L-1 TAK19-N-2 TAK19-N-3 TAK25-D10 TAK25
2003-2 2003-1-C-1 2003-1-C-5 2003-2-A-2 2003-2-A-3 2003-2-C-1 2003-2-C-2 2003-2-H-1 2003-2-H-2 2003-2-A-
2003-2 KAD1 2003-2-C-3 2003-2-C-4 2003-2-C-5 KAD1-A-1 KAD1-A-2 KAD1-G-1 KAD1-G-8 KAD1-G-2 KAD1-G-
KAD15 KAD15-E-8 KAD15-E-9 KAD15-I-6 KAD15-A-2 KAD15-A-3 KAD15-A-6 KAD15-B-6 KAD15-E-3 KAD15-E-5 KAD15-F-
KAD15 BOU1 KAD15-G-6 BOU1-F-4 BOU1-F-5 BOU1-L-5 BOU1-L-6 BOU1-E-3 BOU1-E-6 BOU1-E-10 BOU1-E-11 BOU1-E-
KAD5-C-1 KAD5-D-7 KAD5-E-1 KAD5-E-6 KAD5-E-8 KAD5-I-9 KAD5-E-2 KAD5-E-7 KAD5-E-
ZYA1 ZYA1-C-1 ZYA1-E-1 ZYA1-E-2 ZYA1-E-3 ZYA1-G-1 ZYA1-G-2 ZYA1-L-3 ZYA1-L-7 ZYA1-L-1 ZYA1-L-
ZYA1 ZYA2 ZYA1-A-1 ZYA1-B-6 ZYA1-C-7 ZYA1-E-4 ZYA2-A-1 ZYA2-A-2 ZYA2-C-1 ZYA2-C-2 ZYA2-C-3 ZYA2-D-
2 -Orthopyroxene (continued) ZYA2 ZYA2-D-2 ZYA2-E-13 ZYA2-E-14 ZYA2-E-18 ZYA2-F-1 ZYA2-F-5 ZYA2-F-2 ZYA2-F-6 ZYA2-G-1 ZYA2-G-
ZYA2 ZYA2-G-3 ZYA2-C-6 ZYA2-C-8 ZYA2-D-3 ZYA2-D-4 ZYA2-D-5 ZYA2-E-
TAK8 TAK9 TAK8-D-2 TAK8-E-1 TAK8-L-1 TAK8-L-2 TAK8-M-1 TAK8-N-3 TAK9-A3 TAK9-B1 TAK9-E3 TAK9
TAK10 TAK12 TAK9-H2 TACK10-A3 TACK10-F2 TACK10-I3 TAK12-H-1 TAK12-H-2 TAK12-I-1 TAK12-I-2 TAK12-O-1 TAK12-O-
Ol-websterite TAK12 TAK7 TAK12-A-3 TAK12-B-1 TAK12-E-28 TAK12-M-1 TAK12-E-18 TAK7-A-1 TAK7-A-2 TAK7-C-1 TAK7-B-
TAK7 TAK7-C-2 TAK7-D-4 TAK7-D-1 TAK7-G-1 TAK7-G-4 TAK7-G-2 TAK7-L-2 TAK7-L-1 TAK7-A-
TAK13 TAK7-F-1 TAK7-F-2 TAK13-R-3 TAK13-R-2 TAK13-P-4 TAK13-P-5 TAK13-A-11 TAK13-B-2 TAK13-C-1 TAK13-D-
TAK13 TAK17 TAK13-F-7 TAK13-G-2 TAK13-H-4 TAK13-I-3 TAK13-L-1 TAK13-M-3 TAK13-R-1 TAK13-P-3 TAK17-A-
TAK17-B-5 TAK17-C-4 TAK17-E-1 TAK17-G-2 TAK17-C-6 TAK17-C-7 TAK17-B-1 TAK17-C-
3 -Clinopyroxene Lherzolite TAK16 TAK19 TAK16-F-9 TAK16-G-1 TAK16-C-7 TAK16-C-9 TAK16-F-5c TAK16-F-5d TAK16-F-5e TAK16-L-5 TAK16-L-6 TAK19-B-7 TAK19-C-1 TAK19-C-
TAK19 TAK19-F-3a TAK19-E-4 TAK19-E-5 TAK19-E-7 TAK19-E-8 TAK19-F-4 TAK19-I-1 TAK19-M-1 TAK19-M-3 TAK19-N-1 TAK19-N-4 TAK19-N-
TAK25 TAK25-D1 TAK25-D3 TAK25-D11 TAK25-I1 TAK25-M4 TAK25-A3 TAK25-C10 TAK25-F1 TAK25-G1 TAK25-G2 TAK25-
KAD2 KAD15 KAD2-A1 KAD2-C1 KAD2-E2 KAD2-F1 KAD2-O1 KAD2-B2 KAD15-B-8 KAD15-M-1 KAD15-N-1 KAD15-A-1 KAD15-B-1 KAD15-B-
KAD15 BOU1 KAD15-G-4 KAD15-G-5 KAD15-H-4 KAD15-I-1 KAD15-N-3 BOU1-A-1 BOU1-A-5 BOU1-A-6 BOU1-A-9 BOU1-B-1 BOU1-B-3 BOU1-C-
BOU1 SAI1 BOU1-D-1 BOU1-G-1 BOU1-B-7 BOU1-F-1 BOU1-F-2 BOU1-L-4B SAI1-A1 SAI1-B3 SAI1-G1 SAI1-G4 SAI1-L1 SAI1-
TAK12 TAK12-F-1 TAK12-F-3 TAK12-F-4 TAK12-A-1 TAK12-B-2 TAK12-B-3 TAK12-E-1 TAK12-E-3 TAK12-E-9 TAK12-E-
BOU4 TAK17-B-2 TAK17-B-3 TAK17-C-3 TAK17-C-5 TAK17-G-3 TAK17-L-2 BOU4-A-1 BOU4-B-2 BOU4-C-1 BOU4-D-
BOU4-H-9 BOU4-I-1 BOU4-I-4 BOU4-L-1 BOU4-N-1 BOU4-A-3 BOU4-B-3 BOU4-A-2 BOU4-B-1 BOU4-C-

Figure 1

 1 Figure 1.1 -Digitail terrain model of the Mediterranean region, with major simplified geological structure. White thrust symbols indicate the outer deformation front along the Ionian and the eastern Mediterranean subduction fronts. AB: Algerian Basin; AS: Alboran Sea; AdS: Adriatic Sea; AeS: Aegean Sea; BS: Black Sea; C: Calabria-Peloritani terrane; CCR: Catalan Coast Range; Cr: Crimea; Ct: Crete; Cy: Cyprus; EEP: East European Platform; HP: High Plateaux; KM: Kirsehir Massif; IC: Iberian Chain; IL: Insubric line; IS: Ionian Sea; LS: Levant Sea; LiS: Libyan Sea; MA: Middle Atlas; MM: Maroccan Meseta; MP: Moesian Platform; PB: Provencal Basin; PaB: Pannonian Basin; PS: Pelagian Shelf; RM: Rhodope Massif; S: Sicilian Maghrebides; SP: Saharan Platform; TA: Tunisian Atlas; TS: Tyrrhenian Sea; VT: Valencia Trough. The basins mentioned in the text are shown with red squares. Modified from Cavazza & Wezel (2003).

Figure 1

 1 Figure 1.2 -Paleotectonic recostructions of the Mediterranean region Jolivet & Faccenna (2000).

Figure 1

 1 Figure 1.3 -Digital relief-shaded image of time -space-composition characteristics of magmatic rocks of the western Mediterranean and peripheral orogens.Legend -Rocks type: 1-tholeiites; 2 -Medium-K and high-K calcalkaline plutons (red circles: Eocene plutons from the Alps and adjacent Sava zone); 3 -medium-K and high-K calcalkaline volcaics; 4 -shoshonities; 5 -ultrapotassic volcanics; 6lamproites; 7 -carbonatites; 8 -intraplate volcanics; 9 -rocks from intraplate, large central volcanoes; 10 -volcanics from deep drillings (DSDP and ODP sites and Neapolitan area); 11 -pyroclastic and/or ignimbritic rocks. VV -Veneto volcanic district. FromCavazza et al. (Eds., 2004).

Figure 1

 1 Figure 1.4 -Tectonomagmatic sketch map of the Western Mediterranean. Legend: 1 -Balearic and Tyrrhenian interarc basins; 2 -Cenozoic orogenic volcanism and related mantle sections; 3 -Late Miocene-Quaternary anorogenic volcanicsm and related mantle section; 4 -inferred boundary of the subduction system at different ages: open triangles refer to slab detachments/windows; 5 -compressional thrust front of the Alps, Betic Cordillera and Apennine-Maghrebian chain; 6 -mantle peridotite massifs of Ronda and Beni Bousera. Modified from Beccaluva et al. (2011)

  references therein). The elevation decreases westward, away from the Middle Atlas mountains to the Central Massif of the Moroccan Meseta, towards the Atlantic coastal basins and finally to the Atlantic abyssal plains. South of the Anti-Atlas and Saghro mountains, in the Saharan hamadas (plateaus), elevation decreases both southward, from ca. 1000 m to less than 400 m (Tindouf Basin), and westward to less than 200 m, close to the Atlantic (Tarfaya Basin). Neogene basins are shown along the high Atlas borders (Haouz-Tadla and Bahira Basins to the north, Souss and Ouarzate Basins to the South) or north and east of the Middle Atlas (Guercif and Missour Basins), whereas a large foredeep basin (Gharb) extends southwest of the Rif belt. The continental basement of North Africa is more uplifted in Morocco than in the countries further east, causing the extensive outcrop of Palaeozoic and Precambrian rocks (Fig. 1.6). Palaeozoic rocks form a large culmination within the Mesozoic Atlas domain, whereas Precambrian rocks form similar culmination (boutonnières) in the middle of the Anti-Atlas Paleozoic terranes. Palaeozoic units also occur in the Maghrebide internal zones, similary developed in Morocco (Alboran domain) and in Algeria (Kabylias), but they belong to a disrupted allochtonous terrane and not to the African basement itself.

Figure 1

 1 Figure 1.6 -Extension of the Paleozoic and Precambrian outcrops in Morocco (Northern Provinces) and westernmost Algeria (Traras, Ben Zireg, Bèchar) from Michard et al. (2008).

Figure 1

 1 Figure 1.7 -Schematic structural map of Morocco showing the extension of the Atlas system (Frizon de Lamotte et al., 2008).

Figure. 1

 1 Figure. 1.8 -Paleogeographic map at Liassic times from Frizon de Lamotte et al. (2008).

Fig. 1

 1 Fig. 1.9 -Tectonic map of the Middle Atlas and Missour-High Moulouya and Guercif Basins (From Frizon de Lamotte et al., 2008). OAF: Ait Oufella Fault; B: Boulemane; D: Debdoy; F: Fes; GU: Guercif; I: Ifrane; IZ: Itzer; K: Ksabi; KE: Kenifra; KT: Kasba Tadla; M: Missour; MD: Medelt; ME: Meknes; MO: Mouguer; NMAF: North Middle Atlas Fault; RP: Prerif Ridges (Rides Prerifaines; SMAF: South Middle Atlas Fault; TA: Taourirt; TNTF: Tizi n'Tretten Fault; TZ: Taza).

Figure1. 10 -

 10 Figure1.10 -Petrological map of the Middle Atlas basaltic province (Frizon de Lamotte et al., 2008).

  recognised three periods of alkaline magmatism in the Middle Atlas. The most ancient volcanoes are located along the North Middle Atlas Fault (NMAF) and their ages are Eocene (35 Ma). During Middle and Late Miocene (i.e. from 15 to 6 Ma), a scattered volcanic activity spread throughout the Middle Atlas system, simultaneously with the Rif orogenesis and the uplift of central Morocco. Finally, the third volcanic period is dated Quaternary (i.e. from 1.8 to 0.5 Ma), during a compression phase. The magma uprising occurs in secondary fractured zones on account of the European-African plates collision. According to Frizon de Lamotte et al. (2008), four types of mafic lavas (nephelinites, basanites, alkali basalt and subalkaline basalts; Fig. 1.10) are distinguished in the petrologic map, based on a hundred new major and trace element analyses. It is worth noting that the systematic evolution from orogenic to anorogenic magmatism is present also in Morocco (see chapter 1.1.3) Intermediate and evolved compositions are lacking in the Middle Atlas, while in the Rif system the volcanism evolved through time from calcalkaline to shoshonitic and finally alkaline. The nephelinites (SiO 2 = 36 -41%) usually form small strombolian cones and associated lava flows located along the borders of the volcanic plateau, and most of them were emplaced prior to the other petrologic types. The basanites (SiO 2 = 41 -45%) are the youngest lava type and make up most of the well preserved cones located between Azrou and Itzer. The corresponding lava flows generally overlie the alkali basalt flows. The alkali basalt (SiO 2 = 46 -51 %) represent the dominant petrographic type and their fissural lava flows cover most of the plateau surface.

Figure 1 .

 1 Figure 1.11 -Chondrite-normalised rare earth element patterns and primitive mantlenormalised incompatible element patterns showing the geochemical diversity of the Middle Atlas lavas (Frizon de Lamotte et al., 2008). Alkali basalts, basanites and nephelinites represent relatively primitive magmas (9%<MgO<13%; 45<Co<60 ppm). The subalkaline basalts display some petrographic (i.e. quartz xenocrysts) and geochemical (selective enrichments in Rb, Th, K, depletion in Nb) evidence of crustal contamination. They probably derive from alkali basalt magmas, contamined by continental crust during their ascent.

Figure 1 .

 1 Figure 1.12 -Map of the northern African plate (A) and flow of the Canary plume material under northwest Africa through a subcontinenal lithospheric corridor in a three-dimensional model (B). A: the orange area display the Canary hotspot track on the oceanic side of the northwest African plate with ages of the oldes lavas from each island (red areas) or seamount (gray circles), indicating a southwest-directed age progression and the location of the current plume center beneath the western Canary Island. Also shown are the Atlas Mountain (grey field), location of the northwest African subcontinental lithospheric corridor in green, inferred from profiles (A-F) based on geophysical data, and northwest African Neogene continental intraplate volcanic field. B: the three-dimensional model illustrate show Canary mantle plume material flows along the base of the oceanic lithosphere that thins to the east and into the subcontinental lithospheric corridor beneath the Atlas system, reaching the western Mediterranean. Plum push, eastward-thinning lithosphere, delamination of northwest African subcontinental lithosphere, and subduction suction related to rollback of the subducting slab in the Mediterranean are proposed to be the main mechanisms for causing Canary plume Material to flow ≥ 1500 km to the northeast. From Duggen et al. (2009).

Figure 2

 2 Figure 2.1 -The Middle Atlas basaltic province. View from 15 km above Timahdite, GoogleEarth image with small obliquity. Location: see figure 1.10.

Figure 2 . 2 -

 22 Figure 2.2 -Petrographic classification of the studied mantle xenoliths. The modal compositions are in agreement with the Streckeisen (1973) classification.

  2.4). At last, only two samples (2003-1 and 2003-2) are altered. In particular, in sample 2003-2 alteration affects only olivine grains.In general, the porphyroclasts of olivine have tabular or rounded shape; their size ranges between 1.1 and 8.0 mm. All the porphyroclasts of olivine show kink-band deformation; sometimes, they include small rounded neoblasts of undeformed olivine (Fig.2.5). Locally, the grains of olivine are partially replaced by neoblastic crystallization. The porphyroclasts of orthopyroxene have anhedral shape and dimensions ranging between 0.63 and 9.5 mm. Only in the samples BOU2 and BOU3 the orthopyroxene occurs in interstitial position. Moreover, the grains of orthopyroxene show locally kink-band deformation (Fig.2.6) and clinopyroxene and/or greenish spinel exolution lamellae. Orthopyroxene grains also show some inclusions of small rounded neoblasts of olivine. Both the neoblasts of olivine (from 0.02 to 3.4 mm) and orthopyroxene (from 0.25 to 1.4 mm) are undeformed and show a rounded shape. The grains of clinopyroxene have dimensions ranging between 0.40 and 4.9 mm. Clinopyroxene is interstitial with respect to the other porphyroclasts and shows orthopyroxene and/or greenish spinel exsolution lamellae. The grains of clinopyroxene are deformed only at the contact with the melt pockets. If present, the grains of brownish or greenish spinel (from 0.02 to 5.3 mm) are interstitial respect the other mineralogical phases. Spinel is associated with the melt pockets (Fig.2.7) and, sometimes, it shows inclusions of small rounded neoblasts of orthopyroxene. In both samples KAD6 and KAD14, the grains of brown amphibole occur in interstitial position and have dimensions ranging between 1.0 and 5.6 mm (Fig.2.8). Amphibole is always associated with the melt pockets; it shows irregular grain boundaries documenting that it locally underwent partial melting.

  75 and 5.8 mm. All the porphyroclasts of olivine are characterized by kink band deformation and are partially replaced by neoblastic crystallization. In some porphyroclasts, small rounded neoblasts of olivine or orthopyroxene are included. The porphyroclasts of orthopyroxene have dimensions between 1.1 and 10.0 mm. The orthopyroxene has subhedral to anhedral shape; it includes small rounded neoblasts of olivine and, more rarely, orthopyroxene. The porpyroclasts of orthopyroxene are also characterized by clinopyroxene exsolution lamellae and by kink-band deformation. The neoblasts of olivine and orthopyroxene (grains size from 0.01 to 2.1 and from 0.01 to 1.3 mm, respectively) have in general rounded shape and are undeformed. The grains of clinopyroxene have dimensions ranging from 0.25 to 2.0 mm. They occupy interstitial position relative to the porphyroclasts of olivine or orthopyroxene (Fig.2.13). Moreover, the clinopyroxene is characterized by orthopyroxene and spinel exsolution lamellae. In sample KAD1, some grains of clinopyroxene are almost completely replaced by neoblastic crystallization of new clinopyroxene (Fig.2.14) Only in Amp-lherzolite KAD5, the grains of clinopyroxene are characterized by brown-amphibole exsolution traces surrounded by orthopyroxene exolution lamellae (Fig.2.15).

  2.25) or exsolution lamellae in the porphyroclasts of clinopyroxene (Fig.2.26). These porphyroclasts (from 1.80 to 12.5 mm in size) also show exsolution lamellae of orthopyroxene (Fig.2.27) and, more rarely, of Al-spinel. They are partially replaced by neoblasts (Fig.2.28). In most of the samples, orthopyroxene occurs only as neoblast. In TAK5 sample few porphyroclasts of orthopyroxene (about 4.50 mm in size) are observed: they show double (both clinopyroxene and Al-spinel) exsolution lamellae and curvilinear grain boundary occupied by neoblastic crystallization. The grains of Al-spinel occurs interstitially and range from 0.02 to 1.26 mm in size.The three olivine-websterite samples are characterized by coarse-grained porphyroclastic texture, with fine-to medium-grained neoblastic crystallization of clinopyroxene, orthopyroxene and olivine. These neoblasts locally show mosaic equigranular texture; they are characterized by rounded shape and vary from 0.25 to 8.5 mm in size. In all the samples, the porphyroclasts of clinopyroxene and orthopyroxene (from 0.90 to 8.5 mm in size) have anhedral shape and are partially replaced by neoblastic crystallization. Both the clinopyroxene and orthopyroxene porphyroclasts show double exsolution lamellae (orthopyroxene with Al-spinel and clinopyroxene with Al-spinel, respectively; Fig.2.29 and 2.30) and kink-band deformation.

Fig

  Fig.2.4 -Clinopyroxene grain with spongy rims (nicol+; lherzolite BOU1)

  Figure 3.1A, B and C -Bulk rock Al 2 O 3 , CaO, MgO vs. SiO 2 covariation diagrams for the studied lherzolite samples.

Figure 3

 3 Figure 3.2 -Bulk rock Al 2 O 3 vs. Mg# covaration diagram for the studied pyroxenite samples.

(Figure 3 Figure 3 B

 33 Figure 3.3A, B and C -Bulk rock Al 2 O 3 vs. SiO 2 covariation diagrams for the studied pyroxenite samples.

Figure 3

 3 Figure 3.6 -Chondrite-normalized REE abundances in Morocco lherzolite samples.

Figure 3

 3 Figure 3.7 -Chondrite-normalized trace element patterns in Morocco lherzolite samples.

Figure 3 1

 31 Figure 3.8 -Chondrite-normalized REE abundances in Morocco pyroxenite samples. On the basis of REE patterns, the pyroxenites have been divided in four groups: 1 -BOU4 clinopyroxenite; 2 -TAK3 Grt-websterite; 3 -TAK5, TAK6, TAK8, TAK8, TAK10 and TAK12 Grt-websterites; 4 -TAK 4 Grt-clinopyroxenite and TAK7, TAK13 and TAK17 Ol-websterites.

Figure 3 2 Figure 3

 323 Figure 3.9 -Chondrite-normalized REE patterns in BOU4 clinopyroxenite.

Figure 3 .

 3 Figure 3.12 -Chondrite-normalized trace element patterns in TAK3 Grt-bearing websterite.

Figure 3 .

 3 Figure 3.13 -Chondrite-normalized REE patterns in group 3 pyroxenites.

Figure 3 . 4 Figure 3

 343 Figure 3.14 -Chondrite-normalized trace element patterns in group 3 pyroxenites.

Figure 3 .

 3 Figure 3.16 -Chondrite-normalized trace element patterns in group 4 pyroxenites.

Figure 4 .

 4 Figure 4.1 shows the correlation of the fosterite content of olivine with the clinopyroxene Mgnumber (100Mg/(Mg+Fe 2+ tot )). As a whole, a positive correlation is observed for the analysed samples. The covaration diagram shows an increase in forsterite content of olivines associated with an increase of Mg-number in clinopyroxenes. Only harzburgite ZYA1 deviates from this trend, showing the highest Mg-number associated with an intermediate value of fosterite.

Figure 4

 4 Figure 4.2 -NiO (wt%) vs. the Fo content of olivine (mol%) for the pyroxenite samples.

Figure 4

 4 Figure 4.1 -Fo content of olivine (mol%) vs. clinopyroxene Mg# for lherzolite and harzburgite samples. For simple reading, only the average values have been reported.

  are characterized by higher Cr 2 O 3 values. The covaration diagram reported in figure 4.4 shows a complex correlation between the orthopyroxene Cr 2 O 3 and Al 2 O 3 contents. In general, the Cr 2 O 3

Figure 4 .

 4 Figure 4.3B and C -Orthopyroxene CaO and Cr 2 O 3 contents vs Mg# of the lherzolites and harzburgites. For simple reading, only the cores of the analyzed grains have been reported. Symbols as in figure 3.3A.

Figure 4 . 5 -

 45 Figure 4.5 -FeO vs. MgO covaration diagram for the orthopyroxene grains. For simple reading, only the cores of the analysed grains have been reported. Symbols as in figure 3.3A.

  Fig. 4.8). Samples from group 4 are characterized by etherogeneous chemical compositions of orthopyroxenes. While TAK13 and TAK17 samples are homogeneous, TAK7 sample is variable in terms of Mg-number, Cr 2 O 3 , MgO and FeO. TAK13 and TAK17 samples are characterized by a Mg-number content of about 86 in average, associated with a Cr 2 O 3 content of about 0.07 wt% (Fig.4.6B). Instead, TAK7 sample is characterized by higher value of Mg-number (about 90 in average) associated with higher Cr 2 O 3 (0.36 wt%; Fig.4.6B). Moreover, TAK13 and TAK17 samples show the lower MgO content (31.4 wt%) associated with the higher FeO value (about 8.5 wt%; Fig.4.8). Relative to TAK13 and TAK17 samples, orthopyroxenes from TAK7 Olwebsterite are characterized by higher MgO contents (32.7 wt%) correlated with lower FeO contents (6.5 wt%; Fig. 4.8). Finally, orthopyroxenes from the analized Ol-websterites are characterized by almost homogeneous Al 2 O 3 contents, which are comprised between 4.3 and 5.1 wt% (Fig.4.6A). In general, orthopyroxene Al 2 O 3 and Cr 2 O 3 contents show a positive correlation with the Mg-number value (Fig. 4.6A and B).

  Figure 4.6A shows that only Ol-websterite TAK7 deviates from the positive trend between Al 2 O 3 and Mg-number, showing relatively low Al 2 O 3 contents associated with high Mg-number.

  Figure 4.6B, instead, shows that two websterite samples (namely TAK9 and TAK10) deviate from the positive trend between Cr 2 O 3 and Mg-number, due to the low Cr 2 O 3 associated with high Mg-number. The covaration diagram reported in figure 4.7 shows a generally positive correlation between the Cr 2 O 3 and Al 2 O 3 orthopyroxene contents. Olwebsterite TAK7 deviates from this trend, because it is characterized by relatively low values of Al 2 O 3 associated with high Cr 2 O 3 contents The covaration diagrams presented above are shown in figures 4.9A, B, C and D, along with literature data added for comparative purposes. As for the considered elements, the studied pyroxenites are generally similar in composition to the pyroxenites from Beni Bousera (Northern Morocco,

B

  Figure 4.6A and B -Al 2 O 3 and Cr 2 O 3 contents of orthopyroxene vs Mg#. For simple reading only the cores of the grains are plotted in the covaration diagram.

Figure 4

 4 Figure 4.7 -Orthopyroxene Cr 2 O 3 vs. Al 2 O 3 contents. For simple reading only the cores of the grains are plotted in the covaration diagram.

Figure 4 . 8 -

 48 Figure 4.8 -Covariation diagram between orthopyroxene FeO and MgO contents. For simple reading only the cores of the grains are plotted in the covaration diagram.

B

Figure 4 .Figure 4 .

 44 Figure 4.9A and B -Morocco pyroxenites compared with literature data: orthopyroxene Al 2 O 3 and Cr 2 O 3 contents vs Mg#.

  Ronda and Morocco peridotites. The covariation diagram between Ti and Na (Fig.4.13B) shows that most of the analyzed samples fall in the Morocco and Ronda peridotites fields, whereas clinopyroxenes from harzburgite samples and from SAI1, SAI2 and KAD1 lherzolites have different Na contents. The lower value is observed for the harzburgites and for SAI1 and SAI2 lherzolites, whereas the highest Na content characterizes lherzolite KAD1.

Figure 4 .

 4 Figure 4.10 -Clinopyroxene classification for the analysed peridotite samples.

Figure 4 .B

 4 Figure 4.11A and B -Al 2 O 3 and Cao contents vs Mg# for the analysed clinopyroxenes. For simple reading only the cores of the grains are plotted in the covariation diagram.

Figure 4 .

 4 Figure 4.13A and B -Al and Ti vs. Na (apfu) for the analysed clinopyroxenes.

  ). In general, Mg-number ranges from 81 to 91. In particular, analysed clinopyroxene grains from clinopyroxenite BOU4 are characterized by the lower Mg-number, whereas the clinopyroxene Mg-number for TAK samples is comprised between 86 (Ol-websterite TAK13) and 91 (Grn-bearing websterite TAK9). The clinopyroxene grains have Al 2 O 3 contents ranging from 5.2 (BOU4) to 10.0 wt% (TAK12; Fig.4.15A); relativity lower Al 2 O 3 values characterise the garnet-free pyroxenites. "TAK" samples display an overall negative correlation between clinopyroxene Al 2 O 3 contents and the Mg-number (Fig. 4.15A). Ol-websterites TAK13 and TAK17 (i.e. group 4 pyroxenites) deviate from this trend, being characterized by relativity low values of Mg-number associated with low Al 2 O 3 contents. The CaO contents of clinopyroxene grains range from 20.1 to 21.8 wt%, with the highest values shown by group 1 clinopyroxenite BOU4. All the "TAK" samples are roughly homogeneous as for the CaO content (Fig.4.15B). The Cr vs Al covariation diagram (Fig.4.16) shows that pyroxenites possess similar Cr contents (from ppm level to 0.02 apfu), whereas the Al content ranges between 0.22 and 0.42 apfu. The Al content is positively correlated with Na content (comprised between 0.06 and 0.11 apfu; Fig.4.17A). The Ti content in clinopyroxenes from "TAK" samples is quite homogeneous (from ppm level to 0.01 apfu; Fig.4.17B) and

B

  Figure 4.14 -Classification of clinopyroxenes from the analysed pyroxenite samples. For simply reading, only the average compositions have been plotted.

  78

Figure 4 .

 4 Figure 4.16 -Cr vs. Al (apfu) for the analysed clinopyroxenes.

Figure 4 .

 4 Figure 4.17A and B -Al and Ti vs. Na (apfu) for the analysed clinopyroxenes from pyroxenite samples.

Figure 4 .Figure 4 .

 44 Figure 4.18 -Si vs. Na covariation diagram for clinopyroxene grains. For comparative purpose, the composition fields of peridotite samples are also reported.

Figure

  Figure4.20 -Classification of spinel for the analysed peridotite samples (according to[START_REF] Haggerty | Oxide mineralogy of the upper mantle[END_REF].

Figure 4 .

 4 Figure 4.21 -100*Fe 3+ vs. Cr# covariation diagrams for the spinel grains.

Figure

  Figure 4.22 -Classification of spinel for the analysed pyroxenite samples (according to Haggerty, 1991).

Figure 4 .

 4 Figure 4.23 -100*Fe 3+ vs. Cr# covariation diagram for the spinel grains.

Figure 4 .

 4 Figure 4.24 -Classification of garnet from the analysed pyroxenite samples.

Figure 4 .

 4 Figure 4.26 -Classification of amphibole for the analysed peridotite samples (according to[START_REF] Leake | Nomenclature of amphiboles. Commision a new mineral names, Interantional mineralogical Association[END_REF].

  (2003-1, 2003-2 and HEBRI3), which are characterized by spoon-shaped clinopyroxene REE patterns (without chemical differences from core to rim), with progressive LREE enrichment (La N = 38 -72) and an almost flat pattern in the MREE and HREE region (about 10xC1; La N /Sm N = 3.9 -8.4; La N /Yb N =3.9 -9.6; Fig.5.1A). In particular, 2003-2 sample shows only a weak La enrichment (La N ≈ 12; La N /Sm N = 1.1; La N /Yb N = 1.4). These samples are characterised by a positive Eu anomaly (Eu/Eu* ≈ 1.5, with Eu* = (Sm N x Gd N ) 1/2 ) and negative Pb, Ti and Zr anomalies [Ti/Ti* ≈ 0.35 -0.54, with Ti* = (Dy N x Eu N ) 1/2 ; Zr/Zr* ≈ 0.29 -0.67, with Zr* = (Sm N x Nd N ) ½ ; Fig.5.1B]. Moreover, the Th/U ratio is always < 1, with Th and U concentrations below 100xC1 for 2003-2 and HEBRI3 samples, and ≈ 100xC1 for sample 2003-1. The Ba contents are also variable, from 0.20 ppm (2003-2 and 94 HEBRI3 samples) to 1.9 ppm (2003-1 sample). The REE patterns of these samples are similar to those of the type 1 Morocco lherzolites described by Raffone et al. (2009). According to Raffone and co-workers, the type 1 pattern would represent transient metasomatic zoning, with variable enrichment in the most incompatible elements, formed by an advancing metasomatic percolation front at an increasing distance from the magma source.

Figure 5 .

 5 Figure 5.1A and B -Chondrite-normalized REE (A) and incompatible trace element patterns (B) for clinopyroxenes from group 1 lherzolite xenoliths.

Figure 5 .BFigure 5 .Figure 5 .Figure 5 .B

 5555 Figure 5.2A and B -Chondrite-normalized REE (A) and incompatible trace element patterns (B) for clinopyroxenes from group 2 lherzolite xenoliths (TAK16, TAK19 and KAD15 samples).

  Appendix B. Clinopyroxenes from group 1 clinopyroxenite (i.e. BOU4 sample) show a marked LREE enrichment, associated with a steady fractionation from MREE to HREE (La N /Sm N = 0.69 -0.97; La N /Yb N = 4.0 -7.3; Fig.5.10A). A minor compositional zoning from core to rim is apparent (La N core = 13.0, La N /Ce N = 0.57; La N rim = 20.5; La N /Ce N = 0.68). A slight positive Eu anomaly is observed (Eu/Eu* = 1.2). These patterns are associated with negative Pb and Zr anomalies (Zr/Zr* = 0.43-0.57), and positive Ti anomalies are observed (Ti/Ti* = 1.8 -2.1; Fig.5.10B).

Figure

  Figure 5.10A and B -Chondritenormalized REE (A) and incompatible trace elements patterns (B) for clinopyroxenes from clinopyroxenite BOU4 sample (group 1 pyroxenite).

A

  Clinopyroxenes from the three Ol-websterite samples (group 4) do not show chemical compositional zoning from core to rim. Moreover, clinopyroxene porphyroclasts and neoblasts show similar patterns. Clinopyroxenes from TAK7 Ol-websterite sample show flat MREE to HREE pattern (at about 10xC1), associated with secondary enrichment in La and Ce (< 100xC1; La N /Sm N ≈ 3.0; La N /Yb N ≈ 3.0; La N /Ce N = 1.4; Fig.5.11A). The positive Eu anomaly is apparent. (Eu/Eu* = 1.2). Clinopyroxenes also show negative Pb, Ti and Zr anomalies (Ti/Ti*≈ 0.60; Zr/Zr* ≈ 0.50; Fig.5.11B). The Ba content is comprised between 0.78 and 9.97 ppm and the Th/U ratio is < 1. Clinopyroxene from Ol-websterite TAK7 is comparable with the clinopyroxene from the Morocco type 1 websterite described by Raffone et al. (2009; Fig.5.16A and B). Ol-websterite TAK13 and TAK17 samples possess unusual REE patterns. They are characterized by enrichment in LREE (≈ 10xC1), with a hump at Ce and Nd (La N /Ce N = 0.44 -0.51), a marked positive Eu anomaly (Eu/Eu* = 1.7 -2.0) and a flat HREE pattern (<10xC1; La N /Sm N = 0.84 -1.0; La N /Yb N = 1.6 -2.1; Fig.4.11A). This clinopyroxene pattern is associated with negative Pb and Zr anomalies (Zr/Zr* ≈ 0.40; Fig.5.11B). The samples show positive Sr anomalies (Sr/Sr* = 2.0, with Sr* = (Ce N /Nd N ) 1/2 . Ti anomaly is not observed. Finally, the Ba contents are variable (ranging from 0.0 to 0.21 ppm) and Th/U ratio < 1. Noticeably, positive Eu anomalies have been described by France (2006) for TAK4 Grt-clinopyroxenite (Fig.5.17A).

Figure 5 .

 5 Figure 5.11A and B -Chondrite-normalized REE (A) and incompatible trace element patterns (B) for clinopyroxenes from Ol-websterite TAK7, TAK13 and TAK17 samples (group 4 pyroxenites).

  5.13A) and TAK12 (Fig.5.13A) samples confirm this scenario, preserving clinopyroxene grains that still record the pristine chemical signature before garnet exsolution. Their patterns are almost flat in the MREE and HREE region at below 10xC1. The clinopyroxenes HREE depletion associated with the secondary crystallization of garnet is also reported by Raffone et al. (2009) for the clinopyroxenes from IBA21 websterite sample (Fig.5.15A and B). All the samples show negative Pb and Zr (Zr/Zr* = 0.34 -0.45) anomalies. With the exception for TAK9 and TAK10 samples (Fig.5.14B), all the other Grt-websterites are characterized by positive Ti anomaly (Ti/Ti* = 0.68 -1.4). Clinopyroxenes from TAK5, TAK8, TAK9, TAK10 and TAK12 samples show positive

Figure 5 .

 5 Figure 5.12A and B -Chondrite-normalized REE (A) and incompatible trace elements patterns (B) for clinopyroxenes and garnets from Grt-websterite TAK5 and TAK8 samples (group 3 pyroxenites).

Figure 5 .

 5 Figure 5.13A and B -Chondrite-normalized REE (A) and incompatible trace elements patterns (B) for clinopyroxenes and garnets from Grt-websterite TAK6 and TAK12 samples (group 3 pyroxenites).

Figure 5 .

 5 Figure 5.14A and B -Chondrite-normalized REE (A) and incompatible trace elements patterns (B) for clinopyroxenes from Grt-websterite TAK9 and TAK10 samples (group 3 pyroxenites).

Figure 5 .

 5 Figure 5.17A and B -Chondrite-normalized REE (A) and incompatible trace elements patterns (B) for clinopyroxenes and garnet from Grt-websterite TAK3 sample (group 2) and Grt-clinopyroxentite TAK4 sample (group 4; France, 2006).

  Figure 5.18A, B and C -Chondrite-normalized REE patterns for clinopyroxenes and garnet from Beni Bousera websterites (A), Grtpyroxenites (B) and Grtgraphite pyroxenites (C;[START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF].

  Fig.5.13A; Table 9, Appendix B). The incompatibility diagrams (Fig.5.12B and Fig.5.13B) are characterized by marked negative Ti (Ti/Ti* ≈ 0.05) and Sr (Sr/Sr* = 0.23 -0.38) anomalies.

Figure 5 .

 5 Figure 5.19 -Amphibole to clinopyroxene trace element ratios for Amp-bearing lherzolite KAD5 and KAD14.

Figure 5 .

 5 Figure 5.20 -Garnet to clinopyroxene trace element ratios for Grtwebsterite TAK6 and TAK8.

Figure 5 .

 5 Figure 5.21 -Garnet to clinopyroxene trace element ratios for Moroccan pyroxenites TAK3 and TAK4.

  for the type 1 lherzolites from Middle Atlas. According to the Authors, most of the Middle Atlas peridotites (i.e. type 2 peridotites) fall in the Ocean Island Basalt (OIB) field and overlap the composition of the Moroccan alkaline lavas described by El Azzouzi et al. (1999). The new isotopic data of peridotites from Middle Atlas, together with those reported by Raffone and co-workers for the same area, strongly suggest that only few sectors of the older lithospheric mantle beneath the Middle Atlas escaped isotopic overprinting by alkaline melts during Neogene events.

Figure 6

 6 Figure 6.1 -Nd versus Sr isotope isotope ratios for Middle Atlas lherzolite samples.As mentioned in text, the Moroccan lherzolites fall in the field of beni Bousera[START_REF] Pearson | Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera Peridotites Massif, North Morocco[END_REF], Ronda[START_REF] Reisberg | Futher Sr and Nd isotopic results from peridotites of the Ronda Ultramafic Complex[END_REF] and Hoggar[START_REF] Beccaluva | Intracratonic asthenosphere upwelling and lithosphere rejuvenation beneath the Hoggar swell (Algeria): evidence from HIMU metasomatised lherzolite mantle xenoliths[END_REF] 2008). End-member mantle components afterZindler &[START_REF] Zindler | Geochemical geodynamics[END_REF][START_REF] Hofmann | Mantle geochemistry: the message from oceanic volcanism[END_REF].

Figure 6

 6 Figure 6.2 -Nd versus Sr isotope ratios for Moroccan pyroxenites. As mentioned in text, some samples overlap the fields of the Moroccan alkaline lavas (El Azouzzi et al., 1999) and the Middle Atlas pyroxenites[START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF]. End-member mantle components afterZindler &[START_REF] Zindler | Geochemical geodynamics[END_REF][START_REF] Hofmann | Mantle geochemistry: the message from oceanic volcanism[END_REF].

Figure 6

 6 Figure 6.3 -Clinopyroxenes and olivines δ 18 O values for the analyzed Middle Atlas pyroxenites. The δ 18 O values for various reservoirs (mantle, MORB, HIMU, hydrothermal altered upper and lower oceanic crust) are shown for comparative purpose. Moreover, the composition of websterites and Grt-pyroxenites from Beni Bousera is reported. In comparison with the Beni Bousera pyroxenites, the Middle Atlas samples possess a restricted range of δ 18 O values. Mantle and MORB values from Rollinson (1993); hydrothermal altered upper and lower oceanic crust from Eiler (2001); HIMU values from…

Figure

  Figure 6.7δ 7 Li versus δ 18 O for clinopyroxenes and olivines from Middle Atlas pyroxenites.

Figure 6

 6 Figure 6.6 -Clinopyroxenes and olivines δ 7 Li values for the analyzed clinopyroxenites. δ 7 Li values for various reservoirs (HIMU, OIB, fresh and altered MORB, eclogite and volcanic arc) are reported for comparative purpose. HIMU and OIB values from Halama et al. (2007); fresh MORB data from Chan et al. (2002) and Moriguti & Nakamura (1998b); altered MORB values from Chan et al. (2002); eclogite values from Zack et al. (2003); volcanic arc data from Moriguti & Nakamura (1998b) and Tomascack et al. (2009).

  1 and 3 still record old melt extraction processes, possibly Neo-to Paleoproterozoic in age, documented by MORB-(KAD1 and HEBRI3 samples) and DMM-like (2003-1 sample) isotopic signatures. However, the DMM-like isotopic signatures of 2003-1 lherzolite resulting from Sr and Nd isotopic ratios are not supported by the clinopyroxene REE patterns (see Fig.4.1A). Whereas the other investigated lherzolites are characterized by relatively enriched Sr-Nd isotopic signatures that are associated with depleted (i.e. KAD1) or slightly enriched (i.e. HEBRI3) clinopyroxene LREE patterns, the clinopyroxenes of 2003-1 sample show higher LREE enrichment. According to Raffone et al. (

  Fig. 7.1 -RGB image from France (2006) of the inclusion described in text. R: Si-Mg-Al; G: Si-K-Mg; B: K (alteration phases); Spr: sapphirine.

  figure 7.3 clearly shows the overgrowth of sapphirine on a spinel grain. The sapphirine grains develop at the spinel-garnet contact. In particular, the clinopyroxene+sapphirine association within the spinel is not supported by the reaction proposed by[START_REF] France | Etude pétrologique e géochimique de pyroxénites a grànats: origines et implications géodinamiques[END_REF]. These petrographic features strongly support the reaction described by[START_REF] Morishita | High-pressure aluminous mafic rocks from the Ronda peridotite massif, southern Spain: significance of sapphirine-and corundum-bearing mineral assemblages[END_REF], in which garnet, spinel and plagioclase are the reactants to form clinopyroxene+sapphirine as follow: garnet+spinel+plagioclase = sapphirine+clinopyroxene.

Figure 7

 7 Figure 7.3 -Sapphirine overgrowth on spinel grain. The sapphirine grains develop at spinel-garnet boundaries (Nicol //).

  .

Figure 7

 7 Figure 7.4 -Al 2 O 3 vs. SiO 2 bulk rock content of Morocco pyroxenites. The field of fresh MORB (data from Cooganet al., 2001) and of altered MORB (data from[START_REF] Bach | The geochemical consequences of latestage low-grade alteration of lower ocean crust at the SW Indian Ridge: results from ODP Hole 735 (Leg 176)[END_REF] are reported for comparative purpose.

Figure 7

 7 Figure 7.6δ 7 Li vs. 1/Li of Morocco pyroxenites. Black arrow show trend for alteration of oceanic crust and the grey arrow the fractionation trend for Reyleigh distallation during low-temperature dehydration of the altered crust. Fresh MORB from Chan et al. (2002a) and Moriguti e Nakamura (1998); altered MORB from Chan et al. (1992); eclogite from Zack et al. (2003); arc lavas from Moriguti & Nakamura (1998b).

Figure 7

 7 Figure7.5 -Bulk rock REE pattern of TAK4 Grtclinopyroxenite. Its REE pattern is similar to those reported by[START_REF] Godard | Geochemistry of a long in-situ section of intrusive slow-spread oceanic lithosphere: results from IODP Site U1309 (Atlantis Massif, 30°N Mid-Atlantic-Ridge)[END_REF] for the gabbroic rocks of the Mid-Atlantic ridge. The patterns of altered gabbros from the SW Indian Ridge[START_REF] Bach | The geochemical consequences of latestage low-grade alteration of lower ocean crust at the SW Indian Ridge: results from ODP Hole 735 (Leg 176)[END_REF] and of troctolite from Corsica ophiolite[START_REF] Sanfilippo | The generation of lower crust in (ultra-) slow spreading settings: Insights from the Alpine ophiolites and from Godzilla Megamullion[END_REF] are also report to comparative purpose.

Figure 7

 7 Figure 7.7 -Calculated composition of liquids in equilibrium with clinopyroxenes from group 4 pyroxenites. Liquid have been calculated using cpx/L D values from Skulski et al. (1994).

  for three mantle sectors beneath the East Rift in Tanzania. According to the Authors, the Li features previously described result from the kinetic Li diffusivities in mantle minerals. The Authors hypothesized two main mechanisms able to generate diffusion-driven kinetic Li isotope fractionation in mantle xenoliths: 1 -Li diffusion from grain boundary melts into mineral during the metasomatism or entrainment in the host magma; 2subsolidus intermineral Li-redistribution. The latter can produce both isotopically light (Li-addition) and heavy (Li-loss) minerals and may occur in response to changes in pressure and/or temperature.

Figure 7

 7 Figure 7.8 -Bulk rock REE pattern of TAK13 and TAK17 Ol-websterite. Their REE patterns are similar to those reported by[START_REF] Godard | Geochemistry of a long in-situ section of intrusive slow-spread oceanic lithosphere: results from IODP Site U1309 (Atlantis Massif, 30°N Mid-Atlantic-Ridge)[END_REF] for the gabbroic rocks of the Mid-Atlantic ridge. The patterns of fresh gabbros from SW Indian Ridge (SWIR;[START_REF] Coogan | Whole-rock geochemistry of gabbros from the Southwest Indian Ridge: constraints on geochemical fractionations between the upper and lower oceanic crust and magma chamber processe at (very) slow-spreanding ridges[END_REF] and of troctolite from Corsica ophiolite[START_REF] Sanfilippo | The generation of lower crust in (ultra-) slow spreading settings: Insights from the Alpine ophiolites and from Godzilla Megamullion[END_REF] are also report to comparative purpose.

Figure 7

 7 Figure 7.9 -Calculated composition of liquids in equilibrium with clinopyroxenes from group 2 pyroxenite (TAK3) and TAK5 Grtwebsterite. Liquid have been calculated using cpx/L D values from Skulski et al. (1994).

Figure 7 .

 7 Figure 7.10 -Calculated composition of liquids in equilibrium with clinopyroxenes from group 1 pyroxenite (BOU4) and group 3 pyroxenites (TAK6, TAK8, TAK9, TAK10, TAK12). Liquid have been calculated using cpx/L D values from Skulski et al. (1994).

Figure 8

 8 Figure 8.1 -Schematic illustration of the geodynamic scenario beneath the Middle Atlas (northwesetrn Morocco). The location of the different group of lherzolites and pyroxenites and the sectors of rejuvenated lithosphere formed by intra-cratonic upwelling and accretion of asthenospheric material are shown (modified after Raffone et al., 2009).

  Ol porphyroclasts (2.4 -7.0 mm) have tabular shape; they are locally rounded and show small inclusion of rounded neoblastic Opx or Ol with different optical orientation. The porphyroclasts show kink-band deformation with curvilinear grain boundaries. The neoblasts of Ol (0.40 -2.0 mm) have rounded shape and do not show deformation. Total olivine is about 75%. The porphyroclasts of Opx (1.5 -4.3 mm) have subhedral to anhedral shape and appear weakly deformed. Locally, the grains show Cpx exsolution lamellae. The neoblast (0.25 -1.3 mm) have anhedral shape; they are undeformed and locally rounded. Total orthopyroxene is about 18%.

  grained neoblastic crystallization of Ol, Opx, Cpx and Cr-Spl. The neoblasts show mosaic equigranular texture. Melt pockets also occur; they occupy interstitial position and contain small phenocrysts of Ol and Cpx.The Ol porphyroclasts (2.5 -8.0 mm) have rounded shape, with curvilinear grain boundaries occupied by neoblastic crystallization. The grains of Ol show kink-band deformation and small inclusions of rounded Ol neoblasts. The Ol neoblasts of Ol (0.02 -1.3 mm) have tabular shape, seldom rounded, and are undeformed. Total olivine is about 65%.The Opx porphyroclasts (2.3 -3.1 mm) have anhedral shape; they show kink-band deformation and may contain rounded neoblastic Ol. Some grains of Opx contain Cpx exsolution lamellae. Neoblastic Opx (0.35 -0.63 mm) has subhedral shape and is undeformed. Total orthopyroxene is about 20%.

  neoblastic crystallization of Ol, Opx, Cpx and Cr-Spl. The sample shows foliation due to orientation of the grains. Locally, the grains have spongy rims; the melt pockets are associated with pyroxenes. The Ol porphyroclasts (0.92 -3.0 mm) have elongated shape with kink-band deformation. Locally, small inclusions of rounded Opx, Al-Spl and Ol with different optical orientations are present. The boundaries of porpyroclasts grains are curvilinear and show neoblastic crystallization. Neoblastic Ol (0.28 -0.63 mm) has rounded shape and is not deformed. Total olivine is about 50%. The Opx porphyroclasts (about 3.0 mm) have subhedral/anhedral shape, with irregular and curvilinear grain boundaries where neoblastic crystallization is observed. They show Cpx exsolution lamellae and ondulate extinction. The porphyroclasts are poikilitic and show small inclusions of rounded Ol. The neoblastic Opx (0.30 -0.90 mm) generally has anhedral shape.

  Ol porphyroclasts (1.1 -3.8 mm) have tabular shape. They show kink-band deformation and are partially replaced by neoblast crystallization. The neoblasts of Ol (0.3 -0.8 mm) have rounded shape and are deformed. Total olivine is about 160%. The porphyroclasts of Opx (3.8 -4.8 mm) have subedral to anhedral shape, with curvilinear grain boundaries surrounded by the neoblasts. The porphyroclasts show kink-band deformation and Cpx+ Al-Spl exsolutions lamellae. The neoblasts of Opx (about 0.95 mm in size) have anhedral shape and are not deformed. Total orthopyroxene is about 20%. The grains of Cpx (15%; about 1.4 mm in size) occupy interstitial position. They show Opx and Al-Spl exsolution lamellae. The Cpx is characterized by spongy rims.

  Ol porphyroclasts (3.4 -4.8 mm) have both tabular and rounded shape, with kink-band deformation. The grain boundaries are curvilinear with neoblastic recrystallization. The neoblasts of Ol (0.75 -1.13 mm) have rounded shape and are not deformed. Total olivine is about 60%.The porphyroclasts of Opx (about 6.65 mm in size) have subhedral shape. They are partially replaced by neoblastic crystallization. The porphyroclasts of Opx show Cpx exsolution lamellae and, locally, contain small inclusions of rounded neoblasts of Ol. The neoblasts of Ol (about 0.5 mm) are undeformed and rounded in shape. Total orthopyroxene is about 15%.The grains of Cpx (20%; 1.0 -4.4 mm) are interstitial and show kink-band deformation and Opx ±Al-Spl exsolution lamellae.

  medium-grained neoblastic crystallization of Ol, Opx and Cpx. The sample is strongly altered, although alteration mainly affects the grains of Ol. Moreover, several intergranular melt veins connecting melt pockets cross the sample. The porphyroclasts of Ol (2.3 -4.8 mm) have rounded shape. They show kink-band deformation and are partially replaced by neoblasts. The neoblasts of Ol (about 0.63 mm in size) have rounded shape and are undeformed. Total olivine is about 60%. The porphyroclasts of Opx (3.8 mm) have anhedral shape and show kink-band deformation. The grains are characterized by Cpx exsolution lamellae. Neoblasts occur around curvilinear grain boundaries. The neoblastic Opx (about 1.1 mm in size) has rounded shape and is undeformed. Total orthopyroxene is about 30%. The grains of Cpx (10%; 2.0 -3.8 mm) occur in interstitial position. They show Spl exolution lamellae and are undeformed. Cpx grains have more pronounced spongy rims relative to the other mineralogical phases.

  sample is characterized by coarse-grained porphyroclastic texture, with fine-to medium-grained neoblastic crystallization of Ol, Opx and Cpx. The neoblasts show mosaic equigranular texture. Melt pockets containing fresh glass and ehuedral phenocrysts of Pl, Ol, Px are observed. Locally, these phenocrysts show preferential orientation. The porphyroclasts of Ol (1.1 -12.5 mm) have tabular shape and show kink-band deformation. The grains of Ol are partially replaced by neoblasts. Neoblastic Ol (0.01 -0.25 mm) has rounded shape and is weakly deformed. Total olivine is about 70%. Opx porphyroclasts (1.0 -5.0 mm) have anhedral shape with irregular grain boundaries marked by neoblasts. The porpyroclasts are characterized by kink-band deformation; locally, they show small inclusions of rounded Ol neoblasts. The neoblasts of Opx (0.62 -0.75 mm) have rounded shape and are weakly deformed. Total orthopyroxene is about 25%.

  occurs as corona around Al-Spl and Cpx porphyroclasts (more seldom around the neoblasts) or exsolution lamellae in Cpx porpyroclasts. The porphyroclasts of Cpx (1.80 -4.50 mm) have anhedral shape and are partially replaced by neoblasts. The porphyroclasts are deformed (ondulate extinction) and may contain Opx and Grt (the latter partially replaced by kelyphite) exsolution lamellae. The Cpx locally is poikilitic and show small rounded neoblastic inclusions of Cpx and Opx. The neoblasts of Cpx (0.75 -1.25 mm) have rounded shape and are undeformed. The porphyroclasts of Opx (about 4.50 mmin size) have anhedral shape, with curvilinear grain boundaries marked by neoblastic recrystallization. Seldom the grains of Opx are poikilitic and contain small rounded neoblasts of Opx and Cpx. The neoblasts of Opx (about 0.40 mm in size) have rounded shape. The grains of greenish Al-Spl (0.35 -1.26 mm) are interstitial relative to Opx and Cpx porphyroclasts. They always show kelyphitic coronas. Locally, coronas also occur around Cpx and, more seldom, around fine-grained neoblasts.

  The porphyroclasts of Cpx (1.75 -4.25 mm) have anhedral shape and are partially replaced by neoblasts. The porphyroclasts of Cpx show double exsolution lamellae (both Al-Spl and Opx), but not Grt exsolutions. Moreover, some grains show ondulate extinction. The neoblasts of Cpx (0.75 -1.25 mm) have rounded shape and are undeformed.

  spongy rims. Cpx porphyroclasts (2.5 -10.0 mm) have subhedral to anhedral shape and are partially replaced by neoblastic recrystallization. They are deformed (i.e. ondulate extinction) and show double and parallel exsolution lamellae (both Opx and Al-Spl). The neoblasts of Cpx (0.38 -1.38 mm) have rounded shape and are not deformed. The porphyroclasts of Opx (4.75 -5.25 mm) have anhedral shape, with irregular grain boundaries associated with neoblastic recrystallization. The grains show double exsolution lamellae (both Cpx and Al-Spl) and kink-band deformation. The neoblasts of Opx (about 0.5 mm) have rounded shape and are not deformed. Ol porphyroclasts (3.5 -5.25 mm) have tabular shape, with curvilinear grain boundary marked by neoblastic recrystallization. The porphyroclasts show kink-band deformation. The neoblasts of Ol (about 0.5 mm) have rounded shape and are not deformed.

Table

Table 2

 2

.2 -Summary table of textural characteristics and mineral mode of the studied lherzolites, harzburgites and pyroxenites. Ol: olivine; Opx: orthopyroxene; Cpx: clinopyroxene; Spl: spinel; Amp: amphibole; Grt: garnet

Table 4 .

 4 1 -Summury table of studied pyroxenites.

on a Grt-free basis) Cpx trace element mineral chemistry

	Sample	Lithology	Mineral mode	Mineral mode (Major element	Trace element Whole rock
	TAK5	Grt-websterite	Cpx: 60%; Spl: 15%; Grt: 14%; Opx: 11%	Cpx: 58%; Opx: 23%; Spl: 19%	High Al 2 O 3 content (17.8 -22.4 w t%) associated w ith low SiO 2 content (17.8 w t%)	Group 3: patterns flat in the MREE to HREE region (around 6.5xC1, Gd N /Lu N =1.1); no positive Eu anomalies; variably secondary enrichment in LREE	Convex upw ard REE patterns (La N <10xC1), w ith maximum at Eu N ≤ 10xC1 and LREE enrichment over HREE; positive Eu anomaly is observed
								Convex upw ard REE patterns
	TAK6	Grt-websterite	Cpx: 68%; Opx: 16%; Grt: 12%; Spl: 4%	Cpx: 77%; Opx: 22%; Spl: 7%	Low Al 2 O 3 content (4.6 -12.6 w t%) associated w ith high SiO 2 content (46.8 -49.9 w t%)	Group 3: patterns flat in the MREE to HREE region (around 6.5xC1, Gd N /Lu N =1.1); no positive Eu anomalies; variably secondary enrichment in LREE	(secondary enrichment in La and Ce )and LREE enrichment over HREE; positive Eu anomaly is observed. Some Cpx still record the pristine chemical signature before
								the Grt exsolution
	TAK7	Ol-websterite	Opx: 54%; Ol: 27%; Cpx: 17%; Spl: 2%		Low er Al 2 O 3 content (4.6 -12.6 w t%) associated w ith higher SiO 2 content (46.8 -49.9 w t%). High MgO content	Group 4: patterns very depleted in HREE (around 2.5 x C1; Gd N /Lu N = 0.95); no Eu anomalies; marked LREE enrichment	Flat MREE to HREE pattern (at about 10xC1), associated w ith secondary enrichment in La and Ce (< 100xC1). Positive Eu anomaly is apparent.
	TAK8	Grt-websterite	Cpx: 70%; Grt: 15%; Opx: 10%; Spl: 5%	Cpx: 77%; Opx: 17%; Spl: 6%	Low Al 2 O 3 content (4.6 -12.6 w t%) associated w ith high SiO 2 content (46.8 -49.9 w t%)	Group 3: patterns flat in the MREE to HREE region (around 6.5xC1, Gd N /Lu N =1.1); no positive Eu anomalies; variably secondary enrichment in LREE	Convex upw ard REE patterns (secondary enrichment in La and Ce ) and LREE enrichment over HREE; positive Eu anomaly is observed
	TAK9	Grt-websterite	Cpx: 70%; Grt: 12%; Opx: 11%; Spl: 7%	Cpx: 75%; Opx: 16%; Spl: 9%	Low Al 2 O 3 content (4.6 -12.6 w t%) associated w ith high SiO 2 content (46.8 -49.9 w t%)	Group 3: patterns flat in the MREE to HREE region (around 6.5xC1, Gd N /Lu N =1.1); no positive Eu anomalies; variably secondary enrichment in LREE	Convex upw ard REE patterns (secondary enrichment in La and Ce ) and LREE enrichment over HREE; positive Eu anomaly is observed
	TAK10	Grt-websterite	Cpx: 75%; Opx: 16%; Spl: 9%	Cpx: 74%; Opx: 18%; Spl: 8%	Low Al 2 O 3 content (4.6 -12.6 w t%) associated w ith high SiO 2 content (46.8 -49.9 w t%)	Group 3: patterns flat in the MREE to HREE region (around 6.5xC1, Gd N /Lu N =1.1); no positive Eu anomalies; variably secondary enrichment in LREE	Convex upw ard REE patterns (secondary enrichment in La and Ce ) and LREE enrichment over HREE; positive Eu anomaly is observed
								Convex upw ard REE patterns
	TAK12	Grt-websterite	Cpx: 67%; Opx: 17%; Grt: 15%; Spl: 1%	Cpx: 75%; Opx: 21; Spl: 4%	Low Al 2 O 3 content (4.6 -12.6 w t%) associated w ith high SiO 2 content (46.8 -49.9 w t%)	Group 3: patterns flat in the MREE to HREE region (around 6.5xC1, Gd N /Lu N =1.1); no positive Eu anomalies; variably secondary enrichment in LREE	(secondary enrichment in La and Ce )and LREE enrichment over HREE; positive Eu anomaly is observed. Some Cpx still record the pristine chemical signature before
								the Grt exsolution
					Low Al 2 O 3 content (4.6 -	Group 4: patterns very depleted	Pattern w ith enrichment in LREE (≈
	TAK13	Ol-websterite	Cpx: 43%; Opx: 36%, Ol: 15%; Spl: 6%		12.6 w t%) associated w ith high SiO 2 content	in HREE (around 2.5 x C1; Gd N /Lu N = 0.95); significant positive Eu	10xC1), hump at Ce and Nd and flat HREE region (<10xC1); marked
					(46.8 -49.9 w t%)		anomalies; hump at Ce and Nd	positive Eu anomaly
					Low Al 2 O 3 content (4.6 -	Group 4: patterns very depleted	Pattern w ith enrichment in LREE (≈
	TAK17	Ol-websterite	Cpx: 58%; Opx: 35%; Spl: 7%		12.6 w t%) associated w ith high SiO 2 content	in HREE (around 2.5 x C1; Gd N /Lu N = 0.95); significant positive Eu	10xC1), hump at Ce and Nd and flat HREE region (<10xC1); marked
					(46.8 -49.9 w t%)		anomalies; hump at Ce and Nd	positive Eu anomaly
	BUO4	Clinopyroxenite	Cpx: 96%; Ol: 2%; Pl: 2%		Low Al 2 O 3 content (4.6 -12.6 w t%) associated w ith high SiO 2 content (46.8 -49.9 w t%), High CaO content	Group 1: convex upw ard LREE pattern and an overall fractionation from MREE to HREE	Marked LREE enrichment, associated w ith a fractionation from MREE to HREE; slight positive Eu anomaly is observed
	TAK3	Grt-websterite	Grt: 38%; Opx: 35%; Cpx: 17%; Spl: 10%	Opx: 43%; Cpx: 34%; Spl: 23%	High Al 2 O 3 content (17.8 -22.4 w t%) associated w ith low SiO 2 content (17.8 w t%)	Group 2: spoon-shape pattern, w ith high HREE content, depletion in MREE and enrichment in LREE	Convex upw ard REE patterns (secondary enrichment in LREE) and LREE enrichment over HREE; positive Eu anomaly is observed
	TAK4	Grt-clinopyroxenite	Grt: 52%; Cpx: 32%; Sapph: 13%; Opx: 3%	Cpx: 53%; Opx: 28%; Spl: 19%	High Al 2 O 3 content (17.8 -22.4 w t%) associated w ith low SiO 2 content (17.8 w t%)	Group 4: patterns very depleted in HREE (around 2.5 x C1; Gd N /Lu N = 0.95); significant positive Eu anomalies; marked LREE enrichment	Convex upw ard REE patterns (secondary enrichment in LREE) and LREE enrichment over HREE; marked positive Eu anomaly

Table 7 .

 7 1 -Summary of the main petrographic and chemical features of the investigated pyroxenites. 134 TAK4 pyroxenite represents the crystallization of percolating melts formed at mantle conditions during the Panafrican times. According to the Author, this sample crystallized at shallower pressure relative to the Ariegite subfacies. Moreover, as reported in Table7.1, this sample is characterized by relatively high sapphirine mode (about 13%). Based on observation of the sapphirine rim

	between spinel and garnet (as described in Chapter 2, § 2.5.5), the Author suggested that the
	transition to Ariegite subfacies conditions was mainly governed by a decrease in temperature,
	causing the reaction orthopyroxene+plagioclase+spinel = garnet+sapphirine. According to the
	Author, this reaction is possible in TAK4 sample due to the Al-rich composition of orthopyroxene
	(as reported in Chapter 3, § 3.2.2). Moreover, the presence of inclusions of both sapphirine within
	spinel and spinel+sapphirine+plagioclase+orthopyroxene within clinopyroxene would document the
	inverse reaction (i.e. garnet+sapphirine = orthopyroxene+plagioclase+spinel) before the sample has

equilibrated in the Ariegite subfacies, probably in response to a decrease in pressure. Petrographic features led the Author to hypothesise also an igneous origin for sapphirine. Figure

7

.1 shows the previously described inclusion of spinel+sapphirine+plagioclase+orthopyroxene within the clinopyroxene grain. It is worth noting that the sapphirine grain is characterized by linear grain boundary, a feature that can be hardly reconciled with the destabilization reaction of sapphirine described by

Table data Table 1

 data1

	-Olivine wt% SiO 2 TiO 2 Al 2 O 3 Cr 2 O 3 FeO MnO NiO MgO CaO Na 2 O K 2 O ∑ apfu Si Fe 2+ Fe 3+ Mn Ni Mg Ca Table 1 -Olivine (continued) Lherzolite TAK16 A-5 porphyroclast core 40.77 0.00 0.01 0.00 9.25 0.14 0.33 50.17 0.04 0.01 0.00 100.72 0.989 0.164 0.023 0.003 0.006 1.813 0.001 TAK16 B-2 neoblast wt% SiO 2 40.92 TiO 2 0.00 Al 2 O 3 0.00 Cr 2 O 3 0.00 FeO 8.94 MnO 0.11 NiO 0.32 MgO 49.41 CaO 0.06 Na 2 O 0.01 K 2 O 0.01 ∑ 99.78 apfu Si 1.002 Ti 0.000 Al 0.000 Cr 0.000 Fe 2+ 0.183 Fe 3+ 0.000 Mn 0.002 Ni 0.006 Mg 1.803 Ca 0.002 Na 0.001 K 0.000 Table 1 -Olivine (continued) TAK16 L-4 neoblast wt% SiO 2 41.38 TiO 2 0.00 Al 2 O 3 0.00 Cr 2 O 3 0.00 FeO 9.27 MnO 0.15 NiO 0.38 MgO 49.73 CaO 0.05 Na 2 O 0.01 K 2 O 0.01 ∑ 100.99 apfu Si 1.002 Fe 2+ 0.188 Fe 3+ 0.000 Mn 0.003 Ni 0.007 Mg 1.795 Ca 0.001 Table 1 -Olivine (continued) TAK19 B-1 neoblast wt% SiO 2 40.34 TiO 2 0.01 Al 2 O 3 0.02 Cr 2 O 3 0.00 FeO 8.73 MnO 0.16 NiO MgO 50.30 CaO 0.07 Na 2 O 0.00 K 2 O 0.00 ∑ 100.00 apfu Si 0.983 Table 1 -Olivine (continued) TAK25 C4 porphyroclast core wt% SiO 2 40.83 TiO 2 0.01 Al 2 O 3 0.01 Cr 2 O 3 0.00 FeO 9.43 MnO 0.18 NiO 0.40 MgO 49.76 CaO 0.02 Na 2 O 0.00 K 2 O 0.01 ∑ 100.66 apfu Si 0.993 Fe 2+ 0.177 Fe 3+ 0.014 Mn 0.004 Ni 0.008 Mg 1.803 Ca 0.001 Table 1 -Olivine (continued) TAK25 C2 neoblast wt% SiO 2 40.83 TiO 2 0.01 Al 2 O 3 0.00 Cr 2 O 3 0.00 FeO 9.27 0.12 NiO 0.43 MgO 49.06 CaO 0.03 Na 2 O 0.02 K 2 O 0.00 ∑ 99.77 apfu Si 1.002 Table 1 -Olivine (continued) 2003-1 E-2 porphyroclast rim wt% SiO 2 38.36 TiO 2 0.08 Al 2 O 3 0.05 Cr 2 O 3 0.00 FeO 18.94 MnO 0.34 NiO 0.16 MgO 41.83 CaO 0.38 Na 2 O 0.00 K 2 O 0.00 ∑ 100.15 apfu Si 0.979 Ti 0.002 Al 0.002 Cr 0.000 Fe 2+ 0.368 Fe 3+ 0.036 Mn 0.007 Ni 0.003 Mg 1.592 Ca 0.010 Table 1 -Olivine (continued) 2003-1 C-3 neoblast wt% SiO 2 40.50 TiO 2 0.00 Al 2 O 3 0.05 Cr 2 O 3 0.03 FeO 9.23 MnO 0.14 NiO 0.39 MgO 49.69 CaO 0.05 Na 2 O 0.04 K 2 O 0.01 ∑ 100.12 apfu Si 0.988 Fe 2+ 0.165 Fe 3+ 0.023 Mn 0.003 Ni 0.008 Mg 1.807 Ca 0.001 Table 1 -Olivine (continued) 2003-2 D-5 porphyroclast rim wt% SiO 2 41.27 TiO 2 0.00 Al 2 O 3 0.00 Cr 2 O 3 0.00 FeO 7.16 MnO 0.15 NiO 0.41 MgO 50.91 CaO 0.06 Na 2 O 0.00 K 2 O 0.01 ∑ 99.97 apfu Si 1.001 Fe 2+ 0.145 Fe 3+ 0.000 Mn 0.003 Ni 0.008 Mg 1.840 Ca 0.002 Table 1 -Olivine (continued) KAD1 H-2 porphyroclast rim wt% SiO 2 40.47 TiO 2 0.00 Al 2 O 3 0.00 Cr 2 O 3 0.01 FeO 9.64 MnO 0.14 NiO 0.42 MgO 49.00 CaO 0.05 Na 2 O 0.00 K 2 O 0.00 ∑ 99.73 apfu Si 0.995 Table 1 -Olivine (continued) KAD2 D1 porphyroclast core wt% SiO 2 40.73 TiO 2 0.00 Al 2 O 3 0.00 Cr 2 O 3 0.00 FeO 9.95 MnO 0.14 NiO 0.39 MgO 49.08 CaO 0.03 Na 2 O 0.00 K 2 O 0.02 ∑ 100.35 apfu Si 0.996 Fe 2+ 0.195 Fe 3+ 0.009 Mn 0.003 Ni 0.008 Mg 1.788 Ca 0.001 Table 1 -Olivine (continued) KAD15 E-6 porphyroclast core wt% SiO 2 39.96 TiO 2 0.00 Al 2 O 3 0.01 Cr 2 O 3 0.02 FeO 9.59 MnO 0.15 NiO 0.27 MgO 50.45 CaO 0.06 Na 2 O 0.01 K 2 O 0.00 ∑ 100.53 apfu Si 0.970 Fe 2+ 0.134 Fe 3+ 0.061 Mn 0.003 Ni 0.005 Mg 1.824 Ca 0.002 Na 0.001 K 0.000 Table 1 -Olivine (continued) I-4 porphyroclast rim wt% SiO 2 40.30 TiO 2 0.03 Al 2 O 3 0.01 Cr 2 O 3 0.01 FeO 9.63 MnO 0.17 NiO 0.35 MgO 49.85 CaO 0.05 Na 2 O 0.00 K 2 O 0.00 ∑ 100.40 apfu Si 0.982 Ti 0.001 Al 0.000 Cr 0.000 Fe 2+ 0.161 Fe 3+ 0.035 Mn 0.003 Ni 0.007 Mg 1.810 Ca 0.001 Na 0.000 K 0.000 Table 1 -Olivine (continued) KAD15 C-8 neoblast wt% SiO 2 40.60 TiO 2 0.00 Al 2 O 3 0.03 Cr 2 O 3 0.03 FeO 9.64 MnO 0.18 0.29 MgO 50.36 CaO 0.08 Na 2 O 0.01 K 2 O 0.02 ∑ 101.25 apfu Si 0.972 Fe 2+ 0.096 Fe 3+ 0.052 Mn 0.002 Ni 0.010 Mg 1.860 Ca 0.005 Table 1 -Olivine (continued) KAD15 M-3 neoblast wt% SiO 2 40.37 TiO 2 0.02 Al 2 O 3 0.00 Cr 2 O 3 0.00 FeO 9.63 MnO 0.15 NiO 0.46 MgO 50.19 CaO 0.07 Na 2 O 0.00 K 2 O 0.00 ∑ 100.90 apfu Si 0.978 Fe 2+ 0.152 Fe 3+ 0.043 Mn 0.003 Ni 0.009 Mg 1.812 Ca 0.002 0.002 Table 1 -Olivine (continued) A-6 C-1 C-2 C-5 C-6 porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim 41.03 41.06 40.46 41.19 40.81 0.03 0.00 0.00 0.03 0.02 0.00 0.02 0.00 0.02 0.00 0.00 0.00 0.00 0.01 0.02 9.10 8.89 9.23 9.05 8.99 0.09 0.16 0.11 0.09 0.17 0.39 0.43 0.35 0.38 0.42 49.70 49.79 50.04 49.89 49.82 0.04 0.04 0.04 0.06 0.07 0.01 0.01 0.04 0.00 0.03 0.00 0.00 0.00 0.00 0.00 100.38 100.40 100.27 100.73 100.35 0.999 0.999 0.985 0.999 0.994 0.185 0.180 0.156 0.184 0.170 0.001 0.001 0.032 0.000 0.013 0.002 0.003 0.002 0.002 0.004 0.008 0.008 0.007 0.007 0.008 1.804 1.806 1.815 1.804 1.808 0.001 0.001 0.001 0.002 0.002 0.000 E-1 porphyroclast core 41.30 0.00 0.05 0.07 9.12 0.07 0.36 49.71 0.03 0.00 0.00 100.71 1.002 0.995 0.001 E-1b porphyroclast rim 40.86 0.03 0.00 0.00 8.95 0.17 0.33 49.94 0.03 0.00 0.00 100.31 0.000 0.185 0.173 0.000 0.009 0.001 0.003 0.007 0.006 1.797 1.812 0.000 A-1 C-4 C-8 E-3 F-1 H-4 neoblast neoblast neoblast neoblast neoblast neoblast 40.90 40.79 40.78 41.08 40.98 40.80 0.03 0.06 0.00 0.00 0.00 0.04 0.00 0.02 0.04 0.04 0.00 0.01 0.01 0.05 0.00 0.00 0.00 0.09 9.00 9.08 9.06 9.10 9.05 9.06 0.10 0.15 0.08 0.14 0.15 0.18 0.47 0.35 0.34 0.36 0.33 0.37 50.16 49.76 49.12 49.89 49.34 51.65 0.07 0.06 0.05 0.05 0.06 0.06 0.00 0.03 0.01 0.00 0.02 0.02 0.01 0.00 0.01 0.00 0.00 0.01 100.76 100.34 99.49 100.66 99.94 102.29 0.991 0.993 1.002 0.997 1.002 0.971 0.001 0.001 0.000 0.000 0.000 0.001 0.000 0.001 0.001 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.002 0.166 0.174 0.186 0.181 0.185 0.125 0.016 0.011 0.000 0.004 0.000 0.055 0.002 0.003 0.002 0.003 0.003 0.004 0.009 0.007 0.007 0.007 0.006 0.007 1.812 1.806 1.798 1.805 1.798 1.832 0.002 0.001 0.001 0.001 0.002 0.002 0.000 0.001 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 TAK19 A-2 A-3 F-1 F-2 H-1 H-3 porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast L-1 porphyroclast core 40.82 0.00 0.06 0.00 9.34 0.15 0.30 49.55 0.04 0.01 0.00 100.26 0.000 0.184 0.007 0.003 0.006 1.802 0.000 H-5 neoblast 40.83 0.04 0.03 0.01 9.15 0.14 0.34 49.49 0.05 0.00 0.00 100.07 0.998 0.001 0.001 0.000 0.185 0.002 0.003 0.007 1.803 0.001 0.000 0.000 H-5 core porphyroclast L-2 porphyroclast rim 41.28 0.03 0.03 0.01 8.18 0.15 0.29 50.03 0.08 0.03 0.00 100.10 0.000 0.166 0.000 0.003 0.006 1.813 0.000 L-3 neoblast 40.54 0.04 0.03 0.00 9.04 0.17 0.40 49.83 0.05 0.02 0.00 100.10 0.989 0.001 0.001 0.000 0.164 0.021 0.003 0.008 1.812 0.001 0.001 0.000 H-4 rim neoblast C-4 40.56 40.54 40.62 40.32 40.81 40.61 40.61 40.52 40.76 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.04 0.00 0.03 0.03 0.01 0.02 0.02 0.04 0.00 0.03 0.04 0.00 0.00 0.00 0.05 0.06 0.00 0.01 0.00 0.00 8.45 8.52 8.54 8.30 8.65 8.82 8.72 8.41 8.66 0.17 0.13 0.16 0.13 0.14 0.10 0.15 0.14 0.15 0.38 0.40 0.34 0.35 0.29 0.40 0.39 0.43 0.34 50.43 50.38 50.90 51.29 50.59 50.52 50.83 50.65 50.29 0.06 0.06 0.06 0.12 0.04 0.05 0.06 0.06 0.06 0.00 0.00 0.01 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.01 100.08 100.06 100.66 100.59 100.60 100.54 100.77 100.27 100.31 0.987 0.986 0.982 0.973 0.988 0.984 0.981 0.000 0.000 0.000 0.000 0.145 0.147 0.136 0.114 0.153 0.148 0.139 0.140 0.157 0.027 0.026 0.037 0.053 0.022 0.031 0.038 0.031 0.019 0.004 0.003 0.003 0.003 0.003 0.002 0.003 0.003 0.003 0.007 0.008 0.007 0.007 0.006 0.008 0.008 0.008 0.007 1.828 1.827 1.833 1.845 1.825 1.825 1.830 1.832 1.821 0.001 0.001 0.002 0.003 0.001 0.000 0.000 0.000 0.000 TAK25 D-4 D-5 D-7 E-2 E-3 G-1 L-2 B1 B2 neoblast neoblast neoblast neoblast neoblast neoblast neoblast porphyroclast core porphyroclast rim 40.37 40.66 40.30 41.28 40.78 40.56 40.59 41.42 40.92 0.00 0.00 0.00 0.00 0.03 0.05 0.03 0.04 0.02 0.03 0.00 0.00 0.00 0.00 0.00 0.03 0.00 0.02 0.04 0.00 0.00 0.12 0.19 0.00 0.00 0.00 0.00 8.63 8.48 8.59 8.94 8.90 8.53 8.60 9.22 9.13 0.17 0.14 0.11 0.12 0.16 0.14 0.13 0.02 0.14 0.37 0.39 0.37 0.41 0.41 0.45 0.39 0.34 0.36 50.68 50.39 50.82 36.78 50.46 50.66 50.36 48.90 49.38 0.07 0.05 0.04 0.07 0.03 0.06 0.08 0.01 0.05 0.01 0.02 0.00 0.00 0.01 0.00 0.00 0.01 0.01 0.02 0.00 0.00 0.00 0.02 0.00 0.01 0.00 0.00 100.39 100.13 100.24 87.73 100.98 100.46 100.23 99.95 100.03 0.979 0.989 0.978 1.135 0.985 0.983 0.987 0.000 0.000 0.000 0.000 C6 C8 C5 C7 C9 D5 D6 A2 B4 Ol porfiroclasto core porphyroclast core porphyroclast rim porphyroclast rim porphyroclast rim porphyroclast core porphyroclast rim neoblast neoblast 40.72 41.38 40.68 40.87 38.66 40.67 40.39 40.70 40.60 0.03 0.00 0.00 0.00 0.00 0.01 0.00 0.04 0.04 0.00 0.00 0.01 0.01 0.03 0.00 0.05 0.00 0.01 0.00 0.00 0.00 0.00 0.04 0.00 0.06 0.02 0.00 9.37 9.35 9.39 9.55 9.19 9.38 9.33 9.17 9.11 0.15 0.13 0.16 0.10 0.16 0.12 0.15 0.16 0.13 0.30 0.40 0.30 0.39 0.30 0.32 0.33 0.32 0.38 49.86 49.17 52.17 50.15 52.06 49.28 49.84 49.35 49.67 0.03 0.02 0.02 0.04 0.04 0.03 0.04 0.00 0.01 0.00 0.00 0.00 0.06 0.03 0.04 0.01 0.00 0.00 0.00 0.02 0.01 0.02 0.00 0.01 0.00 0.01 0.00 100.45 100.46 102.74 101.18 100.50 99.86 100.20 99.77 99.96 0.991 1.007 0.963 0.987 0.932 0.996 0.985 0.000 0.001 0.000 0.000 0.173 0.190 0.112 0.165 0.049 0.183 0.162 0.185 0.173 0.017 0.000 0.074 0.028 0.136 0.009 0.028 0.003 0.013 0.003 0.003 0.003 0.002 0.003 0.003 0.003 0.003 0.003 0.006 0.008 0.006 0.007 0.006 0.006 0.007 0.006 0.007 1.808 1.784 1.841 1.806 1.870 1.799 1.811 1.803 1.809 0.001 0.001 0.000 0.000 0.000 0.000 2003-1 C3 D9 F2 Mb C-8 C-9 D-1 D-2 E-1 neoblast neoblast neoblast neoblast porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core 40.71 41.67 40.03 41.07 40.45 39.96 40.34 40.09 40.15 0.00 0.02 0.01 0.00 0.00 0.02 0.00 0.07 0.00 0.03 0.01 0.00 0.06 0.01 0.00 0.05 0.02 0.00 0.12 0.03 0.03 0.11 0.02 0.00 0.09 0.00 0.00 9.67 9.49 9.57 8.79 9.40 9.18 8.99 10.32 9.25 0.23 0.11 0.14 0.14 0.10 0.10 0.17 0.15 0.12 0.36 0.36 0.33 0.15 0.32 0.36 0.32 0.39 0.44 49.32 49.14 49.21 49.62 49.68 49.48 49.97 48.85 49.40 0.04 0.03 0.01 0.20 0.05 0.11 0.07 0.25 0.07 0.00 0.03 0.01 0.00 0.00 0.00 0.00 0.03 0.00 0.02 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 100.51 100.89 99.37 100.15 100.03 99.20 100.01 100.17 99.44 0.993 1.010 0.986 1.001 0.988 0.984 0.984 0.000 0.000 0.000 0.000 F-1 F-2 H-1 H-2 A-3 A-6 B-3 B-4 C-2 porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim neoblast neoblast neoblast neoblast neoblast 40.27 38.46 40.63 40.37 40.40 40.44 40.42 40.29 39.97 0.00 0.06 0.00 0.00 0.05 0.00 0.00 0.04 0.06 0.00 0.03 0.02 0.02 0.03 0.04 0.00 0.02 0.02 0.00 0.01 0.00 0.05 0.04 0.00 0.00 0.05 0.03 9.21 20.41 9.16 9.03 9.04 9.28 9.32 9.35 9.55 0.15 0.42 0.15 0.16 0.06 0.09 0.08 0.12 0.13 0.33 0.13 0.32 0.34 0.34 0.39 0.31 0.31 0.30 49.88 40.88 49.34 49.90 49.71 49.79 49.82 49.89 50.02 0.05 0.35 0.07 0.13 0.18 0.09 0.07 0.06 0.06 0.00 0.00 0.01 0.04 0.02 0.00 0.00 0.00 0.01 0.00 0.01 0.00 0.01 0.00 0.00 0.01 0.01 0.00 99.89 100.75 99.70 100.05 99.87 100.12 100.03 100.14 100.14 0.984 0.983 0.996 0.985 0.988 0.987 0.987 0.983 0.975 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.001 0.001 0.000 0.001 0.000 0.000 0.001 0.001 0.000 0.001 0.000 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.001 0.001 0.157 0.405 0.181 0.153 0.163 0.164 0.164 0.159 0.147 0.032 0.031 0.007 0.031 0.022 0.025 0.026 0.032 0.048 0.003 0.009 0.003 0.003 0.001 0.002 0.002 0.003 0.003 0.007 0.003 0.006 0.007 0.007 0.008 0.006 0.006 0.006 1.817 1.557 1.803 1.814 1.811 1.811 1.813 1.814 1.818 0.001 0.010 0.002 0.003 0.005 0.000 0.000 0.000 0.000 2003-2 C-4 D-4 G-5 G-7 A-4 A-5 D-1 D-2 D-4 neoblast neoblast neoblast neoblast porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core 40.74 40.29 40.43 40.35 40.70 40.42 40.60 40.29 40.62 0.00 0.00 0.00 0.00 0.02 0.02 0.03 0.00 0.00 0.02 0.06 0.03 0.01 0.02 0.00 0.00 0.00 0.00 0.03 0.09 0.00 0.00 0.00 0.05 0.02 0.03 0.01 9.36 9.08 9.08 9.21 9.09 8.67 9.53 9.49 9.72 0.13 0.15 0.18 0.08 0.12 0.17 0.14 0.14 0.12 0.33 0.38 0.47 0.34 0.39 0.34 0.35 0.38 0.34 49.36 49.55 49.71 49.99 49.88 50.17 49.22 49.04 49.34 0.07 0.07 0.09 0.14 0.07 0.05 0.06 0.07 0.05 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.03 0.02 0.00 0.01 0.01 0.00 0.00 0.01 0.01 0.01 0.00 100.04 99.69 100.00 100.11 100.29 99.90 99.99 99.48 100.22 0.997 0.987 0.988 0.984 0.991 0.986 0.994 0.001 0.000 0.000 0.000 0.186 0.164 0.162 0.155 0.169 0.150 0.184 0.177 0.183 0.006 0.022 0.024 0.033 0.016 0.027 0.011 0.018 0.016 0.003 0.003 0.004 0.002 0.003 0.004 0.003 0.003 0.003 0.007 0.007 0.009 0.007 0.008 0.007 0.007 0.008 0.007 1.800 1.810 1.810 1.816 1.811 1.824 1.797 1.798 1.797 0.002 0.002 0.002 0.004 0.002 0.001 0.000 0.000 0.000 0.000 KAD1 G-1 G-2 A-8 A-9 E-1 E-2 F-1 F-2 H-1 porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core 40.59 40.87 40.92 40.58 40.82 40.56 40.70 40.58 40.45 0.04 0.00 0.00 0.01 0.00 0.01 0.03 0.05 0.00 0.00 0.00 0.00 0.01 0.00 0.01 0.00 0.01 0.03 0.05 0.00 0.03 0.06 0.05 0.00 0.00 0.02 0.00 9.76 9.31 9.93 9.87 10.11 9.91 10.01 9.71 10.13 0.09 0.13 0.12 0.16 0.21 0.11 0.15 0.11 0.13 0.42 0.41 0.33 0.37 0.41 0.38 0.37 0.35 0.40 49.59 49.90 49.41 48.72 48.91 48.99 49.20 49.15 49.10 0.06 0.05 0.04 0.05 0.04 0.03 0.02 0.08 0.02 0.00 0.00 0.04 0.02 0.02 0.01 0.01 0.00 0.02 0.00 0.00 0.01 0.01 0.00 0.00 0.01 0.00 0.00 100.61 100.66 100.84 99.86 100.56 99.99 100.49 100.06 100.29 0.988 0.993 0.995 0.998 0.997 0.995 0.994 0.000 0.000 0.000 0.000 0.178 0.174 0.190 0.199 0.201 0.193 0.192 0.189 0.186 0.021 0.015 0.012 0.004 0.005 0.010 0.012 0.010 0.021 0.002 0.003 0.002 0.003 0.004 0.002 0.003 0.002 0.003 0.008 0.008 0.007 0.007 0.008 0.007 0.007 0.007 0.008 1.799 1.806 1.790 1.785 1.781 1.791 1.790 1.794 1.790 0.002 0.000 0.000 0.000 0.000 KAD2 A-5 B-3 C-2 C-4 G-4 G-6 O-11 E4 E5 neoblast neoblast neoblast neoblast neoblast neoblast neoblast porphyroclast core porphyroclast rim 41.51 40.46 40.95 41.06 40.63 40.92 40.95 40.71 40.80 0.00 0.00 0.00 0.01 0.03 0.00 0.00 0.00 0.02 0.02 0.02 0.03 0.00 0.00 0.01 0.00 0.00 0.03 0.12 0.01 0.07 0.01 0.00 0.00 0.01 0.04 0.00 10.47 10.10 9.85 9.87 9.95 10.15 9.91 9.83 9.82 0.10 0.10 0.18 0.19 0.13 0.11 0.13 0.16 0.14 0.27 0.36 0.49 0.43 0.47 0.42 0.34 0.33 0.36 47.62 49.63 48.91 48.91 49.14 49.02 49.23 49.31 49.12 0.03 0.01 0.04 0.04 0.04 0.03 0.03 0.02 0.05 0.02 0.00 0.00 0.02 0.00 0.00 0.01 0.00 0.01 0.01 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.00 100.18 100.69 100.53 100.54 100.39 100.65 100.61 100.40 100.35 1.017 0.985 1.000 1.002 0.993 0.999 0.998 0.000 0.000 0.000 0.000 KAD15 H2 H1 N2 N1 E6 C3 F3 C-6 E-1 porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core neoblast neoblast neoblast porphyroclast core Ol porfiroclasto core 40.86 40.98 40.67 40.55 40.66 40.73 40.62 40.15 40.55 0.00 0.01 0.01 0.01 0.00 0.03 0.00 0.00 0.00 0.03 0.02 0.03 0.05 0.02 0.05 0.01 0.02 0.02 0.07 0.01 0.05 0.02 0.03 0.00 0.00 0.01 0.00 10.14 9.84 9.91 9.83 9.71 9.88 9.88 9.73 9.34 0.16 0.17 0.14 0.18 0.13 0.14 0.19 0.13 0.17 0.37 0.38 0.29 0.34 0.38 0.22 0.28 0.35 0.38 49.14 49.58 49.46 49.35 49.08 49.54 48.85 49.84 49.72 0.11 0.04 0.06 0.04 0.10 0.05 0.09 0.07 0.06 0.02 0.00 0.00 0.00 0.00 0.00 0.01 0.02 0.00 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.90 101.03 100.62 100.36 100.12 100.63 99.93 100.31 100.24 0.995 0.994 0.991 0.990 0.996 0.991 0.997 0.000 0.000 0.000 0.000 0.196 0.189 0.185 0.183 0.192 0.186 0.197 0.155 0.169 0.010 0.011 0.017 0.018 0.007 0.015 0.006 0.044 0.021 0.003 0.003 0.003 0.004 0.003 0.003 0.004 0.003 0.003 0.007 0.007 0.006 0.007 0.008 0.004 0.006 0.007 0.007 1.782 1.793 1.795 1.796 1.791 1.797 1.787 1.810 1.807 0.003 0.001 0.001 0.001 0.003 0.000 0.000 0.000 0.000 E-2 E-7 F-3 F-1 G-1 G-2 H-1 H-2 I-3 porphyroclast rim porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core 40.47 40.50 40.20 40.32 40.37 40.40 40.45 40.74 40.48 0.02 0.04 0.00 0.02 0.01 0.00 0.01 0.01 0.00 0.02 0.02 0.01 0.00 0.03 0.00 0.00 0.01 0.02 0.01 0.00 0.00 0.00 0.00 0.01 0.00 0.08 0.02 9.59 9.65 9.79 9.76 9.60 9.44 9.80 8.96 9.49 0.17 0.12 0.18 0.12 0.13 0.13 0.21 0.11 0.19 0.29 0.48 0.29 0.30 0.35 0.34 0.40 0.24 0.37 49.87 50.08 50.12 49.75 49.91 49.95 49.79 50.01 49.85 0.07 0.04 0.07 0.06 0.08 0.05 0.04 0.10 0.08 0.00 0.04 0.02 0.00 0.00 0.00 0.00 0.03 0.00 0.02 0.01 0.00 0.00 0.00 0.01 0.02 0.00 0.00 100.54 100.99 100.68 100.32 100.48 100.34 100.73 100.28 100.51 0.984 0.981 0.976 0.983 0.982 0.984 0.983 0.000 0.000 0.001 0.000 0.164 0.157 0.149 0.166 0.161 0.160 0.166 0.166 0.164 0.031 0.038 0.049 0.033 0.034 0.033 0.034 0.017 0.029 0.004 0.003 0.004 0.002 0.003 0.003 0.004 0.002 0.004 0.006 0.009 0.006 0.006 0.007 0.007 0.008 0.005 0.007 1.808 1.807 1.813 1.808 1.810 1.813 1.804 1.814 1.808 0.002 0.001 0.002 0.001 0.002 0.001 0.001 0.003 0.002 0.000 0.002 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 A-5 B-2 B-11 B-12 B-14 B-15 B-16 B-19 B-20 neoblast neoblast neoblast neoblast neoblast neoblast neoblast neoblast neoblast 40.48 40.01 40.34 40.36 40.25 40.88 40.34 40.53 40.52 0.00 0.02 0.03 0.03 0.04 0.01 0.03 0.00 0.00 0.04 0.01 0.01 0.04 0.05 0.06 0.05 0.04 0.02 0.02 0.02 0.10 0.05 0.00 0.00 0.07 0.00 0.00 9.84 9.65 8.14 8.09 9.47 7.33 7.31 9.45 9.48 0.18 0.22 0.15 0.16 0.12 0.11 0.11 0.18 0.17 0.33 0.40 0.22 0.09 0.49 0.35 0.52 0.31 0.32 50.02 49.71 51.98 51.20 50.13 51.77 51.77 49.96 49.59 0.09 0.06 0.17 0.15 0.07 0.16 0.19 0.07 0.06 0.00 0.01 0.02 0.01 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.01 0.00 0.01 101.00 100.11 101.15 100.19 100.62 100.69 100.40 100.53 100.17 1.066 1.068 1.074 1.059 0.981 0.977 0.966 0.977 0.977 0.012 0.012 0.011 0.013 0.000 0.000 0.001 0.001 0.001 0.428 0.425 0.418 0.429 0.001 0.000 0.000 0.001 0.001 0.032 0.031 0.037 0.035 0.000 0.000 0.002 0.001 0.000 0.087 0.088 0.089 0.086 0.162 0.153 0.098 0.121 0.150 0.000 0.000 0.000 0.000 0.037 0.044 0.065 0.043 0.042 0.002 0.002 0.002 0.002 0.004 0.004 0.003 0.003 0.003 0.001 0.002 0.002 0.004 0.006 0.008 0.004 0.002 0.010 0.674 0.674 0.662 0.678 1.806 1.810 1.856 1.847 1.814 0.298 0.291 0.292 0.296 0.002 0.002 0.004 0.004 0.002 0.173 0.180 0.189 0.176 0.000 0.000 0.001 0.000 0.000 0.013 0.014 0.013 0.014 0.000 0.000 0.000 0.000 0.000 D-3 D-4 E-10 E-11 F-4 F-10 G-3 H-3 I-2 neoblast neoblast neoblast neoblast neoblast neoblast neoblast neoblast neoblast 40.32 40.64 40.58 40.21 40.57 39.94 40.63 40.19 40.45 0.08 0.00 0.01 0.00 0.02 0.00 0.03 0.02 0.00 0.00 0.03 0.01 0.00 0.05 0.03 0.03 0.00 0.00 0.00 0.04 0.00 0.01 0.02 0.04 0.00 0.00 0.00 9.60 9.54 9.66 9.81 9.66 9.52 9.72 9.68 9.55 0.15 0.14 0.13 0.13 0.13 0.11 0.16 0.17 0.11 0.41 0.31 0.37 0.35 0.42 0.36 0.40 0.36 0.32 50.10 49.86 49.63 50.16 50.14 50.05 49.72 49.91 49.72 0.06 0.06 0.07 0.05 0.05 0.09 0.05 0.05 0.04 0.00 0.00 0.01 0.03 0.02 0.00 0.00 0.03 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.01 0.00 0.00 100.73 100.63 100.47 100.75 101.07 100.13 100.75 100.42 100.20 0.985 0.989 0.976 0.980 0.982 0.974 0.987 0.001 0.000 0.000 0.000 0.164 0.173 0.113 0.155 0.160 0.144 0.174 0.153 0.169 0.028 0.021 0.048 0.040 0.036 0.051 0.024 0.044 0.026 0.004 0.004 0.003 0.004 0.003 0.002 0.003 0.004 0.002 0.006 0.006 0.005 0.006 0.008 0.007 0.008 0.007 0.006 1.810 1.805 1.848 1.811 1.808 1.819 1.801 1.811 1.808 0.002 0.002 0.004 0.002 0.001 0.000 0.000 0.000 0.000 BOU1 O-1 O-2 A-4 A-3 B-5 B-6 E-4 E-9 E-16 neoblast neoblast porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core Ol porfiroclasto core porphyroclast core 40.28 40.31 37.42 41.01 39.70 40.03 39.84 40.14 40.02 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.00 0.02 0.01 0.02 0.02 0.02 0.00 0.00 0.06 0.00 0.07 0.00 0.00 0.04 0.00 0.02 0.00 9.70 9.63 10.56 10.38 10.56 10.04 10.33 10.60 10.53 0.12 0.14 0.18 0.13 0.17 0.18 0.21 0.14 0.17 0.39 0.33 0.31 0.38 0.44 0.27 0.41 0.29 0.29 50.30 49.60 43.34 47.10 47.67 48.37 48.45 48.40 48.09 0.05 0.08 0.09 0.14 0.07 0.11 0.07 0.07 0.08 0.00 0.00 0.03 0.00 0.00 0.01 0.02 0.00 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.02 100.93 100.09 92.01 99.15 98.63 99.07 99.35 99.68 99.21 0.975 0.985 1.005 1.016 0.991 0.992 0.985 0.001 0.000 0.000 0.000 0.149 0.167 0.237 0.215 0.203 0.192 0.183 0.200 0.202 0.048 0.030 0.000 0.000 0.017 0.016 0.030 0.018 0.016 0.003 0.003 0.004 0.003 0.004 0.004 0.004 0.003 0.004 0.008 0.006 0.007 0.008 0.009 0.005 0.008 0.006 0.006 1.815 1.806 1.735 1.739 1.774 1.786 1.785 1.780 1.777 0.001 0.002 0.003 0.004 BOU1 E-5 E-12 F-7 F-10 F-6 F-11 I-1 I-2 L-1 L-4 porphyroclast rim porphyroclast rim porphyroclast core porphyroclast core porphyroclast rim porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core porphyroclast core wt% SiO 2 39.65 40.20 40.42 40.25 40.18 40.56 40.74 40.38 40.47 40.56 TiO 2 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.01 0.00 0.00 Al 2 O 3 0.02 0.04 0.00 0.05 0.03 0.04 0.00 0.00 0.02 0.07 Cr 2 O 3 0.01 0.00 0.01 0.00 0.00 0.00 0.01 0.00 0.01 0.07 FeO 10.30 10.24 10.57 10.48 10.19 10.04 10.27 10.18 10.35 10.20 MnO 0.19 0.15 0.15 0.15 0.17 0.16 0.11 0.16 0.15 0.18 NiO 0.39 0.34 0.29 0.39 0.42 0.29 0.36 0.31 0.36 0.35 MgO 48.76 48.38 48.71 48.42 48.62 48.07 48.17 48.32 48.18 47.64 CaO 0.14 0.09 0.06 0.05 0.05 0.04 0.07 0.13 0.06 0.06 Na 2 O 0.00 0.00 0.01 0.01 0.00 0.01 0.00 0.00 0.00 0.00 K 2 O 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 ∑ 99.46 99.45 100.21 99.80 99.66 99.22 99.76 99.49 99.61 99.14 apfu Si 0.978 0.993 0.992 0.992 0.990 1.004 1.004 0.998 Table 1 -Olivine (continued) BOU1 L-2 L-3 A-8 A-11 E-7 E-8 E-18 F-3 G-3 G-6 porphyroclast rim porphyroclast rim neoblast neoblast neoblast neoblast neoblast neoblast neoblast neoblast wt% SiO 2 40.45 40.85 40.05 40.22 40.17 40.32 40.48 40.51 54.58 40.34 TiO 2 0.04 0.00 0.04 0.00 0.00 0.00 0.05 0.00 0.07 0.01 Al 2 O 3 0.01 0.03 0.03 0.04 0.00 0.04 0.04 0.06 4.47 0.04 Cr 2 O 3 0.04 0.08 0.02 0.00 0.00 0.00 0.00 0.00 0.39 0.04 FeO 10.28 10.53 10.54 10.42 10.20 10.34 10.43 10.37 6.98 10.65 MnO 0.17 0.21 0.17 0.12 0.12 0.10 0.10 0.16 0.18 0.15 NiO 0.37 0.34 0.36 0.34 0.32 0.23 0.32 0.05 0.41 MgO 48.49 47.99 48.27 48.72 48.66 48.42 48.12 47.94 32.06 48.87 CaO 0.11 0.10 0.06 0.05 0.05 0.07 0.06 0.06 0.75 0.05 Na 2 O 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.07 0.02 K 2 O 0.00 0.00 0.01 0.01 0.00 0.00 0.01 0.00 0.01 0.00 ∑ 99.92 100.16 99.53 99.94 99.54 99.62 99.53 99.42 99.61 100.58 apfu Si 0.995 1.004 0.990 0.989 0.991 0.995 1.000 1.002 Table 1 -Olivine (continued) BOU1 SAI1 H-1 B1 B2 C1 C2 D1 D2 F7 F8 G7 neoblast porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core wt% SiO 2 39.52 41.03 41.47 41.31 41.23 41.30 40.89 40.76 41.10 40.92 TiO 2 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 Al 2 O 3 0.04 0.00 0.02 0.02 0.00 0.03 0.01 0.03 0.01 0.07 Cr 2 O 3 0.02 0.01 0.06 0.00 0.03 0.00 0.00 0.04 0.06 0.00 FeO 10.43 10.40 10.18 10.20 9.58 10.21 10.29 10.10 9.85 10.60 MnO 0.09 0.20 0.13 0.15 0.15 0.19 0.18 0.20 0.12 0.17 NiO 0.29 0.36 0.33 0.33 0.29 0.29 0.29 0.39 0.36 0.29 MgO 45.70 48.71 48.20 48.51 48.77 48.24 48.65 49.07 48.98 49.21 CaO 0.06 0.05 0.05 0.04 0.08 0.04 0.09 0.04 0.04 0.04 Na 2 O 0.05 0.02 0.00 0.02 0.00 0.00 0.01 0.02 0.00 0.01 K 2 O 0.01 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.01 0.00 ∑ 96.21 100.79 100.44 100.58 100.14 100.30 100.40 100.64 100.52 101.32 apfu Si 1.011 1.001 1.013 1.008 1.008 1.010 1.001 0.994 Table 1 -Olivine (continued) SAI1 G3 I1 I2 D3 D4 E5 F1 G6 H1 H2 porphyroclast rim porphyroclast core porphyroclast rim neoblast neoblast neoblast neoblast neoblast neoblast neoblast wt% SiO 2 41.08 41.37 41.32 41.21 41.19 41.40 41.14 41.20 41.25 41.19 TiO 2 0.01 0.00 0.06 0.00 0.00 0.06 0.00 0.03 0.00 0.00 Al 2 O 3 0.01 0.03 0.04 0.02 0.00 0.03 0.00 0.00 0.01 0.00 Cr 2 O 3 0.07 0.00 0.04 0.00 0.02 0.14 0.00 0.04 0.00 0.00 FeO 10.19 10.28 9.70 10.26 10.40 9.95 10.57 10.17 10.55 10.44 MnO 0.17 0.18 0.14 0.21 0.19 0.18 0.25 0.21 0.17 0.19 NiO 0.33 0.29 0.30 0.34 0.28 0.36 0.26 0.32 0.32 MgO 49.03 48.86 49.18 48.81 48.76 48.68 48.50 48.89 48.57 48.89 CaO 0.15 0.03 0.05 0.05 0.07 0.20 0.03 0.04 0.06 0.12 Na 2 O 0.02 0.01 0.00 0.00 0.02 0.02 0.04 0.00 0.00 0.03 K 2 O 0.00 0.00 0.00 0.00 0.01 0.01 0.00 0.00 0.01 0.00 ∑ 101.07 101.09 100.82 100.86 100.99 100.96 100.89 100.84 100.94 101.18 apfu Si 0.999 1.005 1.004 1.004 1.003 1.006 1.004 1.003 Table 1 -Olivine (continued) SAI1 SAI2 H3 B3 B6 B4 B5 H1 H2 H4 I1 I2 neoblast porphyroclast core porphyroclast core porphyroclast rim porphyroclast rim porphyroclast core porphyroclast rim porphyroclast rim porphyroclast core porphyroclast rim wt% SiO 2 40.87 40.40 40.38 40.16 40.24 39.23 39.66 39.31 40.73 41.04 TiO 2 0.02 0.01 0.00 0.00 0.00 0.00 0.03 0.00 0.05 0.02 Al 2 O 3 0.00 0.00 0.00 0.04 0.03 0.03 0.01 0.04 0.00 0.03 Cr 2 O 3 0.00 0.00 0.00 0.06 0.00 0.00 0.00 0.04 0.00 0.03 FeO 10.99 10.01 10.04 10.49 10.18 10.08 9.37 9.19 10.38 9.59 MnO 0.19 0.16 0.17 0.17 0.16 0.17 0.13 0.17 0.13 0.11 NiO 0.37 0.37 0.35 0.37 0.31 0.44 0.37 0.34 0.39 0.29 MgO 48.23 48.90 49.44 48.91 49.42 49.38 49.31 49.96 49.48 49.40 CaO 0.07 0.02 0.02 0.07 0.03 0.02 0.13 0.10 0.04 0.06 Na 2 O 0.03 0.00 0.01 0.00 0.00 0.02 0.00 0.00 0.02 0.03 K 2 O 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.00 0.00 ∑ 100.77 99.87 100.42 100.27 100.38 99.37 99.01 99.15 101.22 100.59 apfu Si 1.001 0.993 0.985 0.984 0.983 0.966 0.979 0.966 0.000 0.000 0.000 0.000 Table 1 -Olivine (continued) SAI2 L1 L2 M1 M2 A5 A6 A9 B1 B2 C2 porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim neoblast neoblast neoblast neoblast neoblast neoblast wt% SiO 2 41.07 40.74 40.76 40.76 40.76 41.20 41.00 41.02 40.47 40.93 TiO 2 0.00 0.07 0.00 0.00 0.00 0.00 0.02 0.00 0.00 0.00 Al 2 O 3 0.00 0.20 0.00 0.06 0.05 0.02 0.02 0.02 0.02 0.01 Cr 2 O 3 0.04 0.07 0.01 0.01 0.05 0.05 0.09 0.00 0.00 0.07 FeO 10.00 13.40 10.31 9.85 9.42 9.73 9.82 9.95 10.11 9.43 MnO 0.14 0.21 0.15 0.20 0.18 0.19 0.14 0.18 0.19 0.14 0.31 0.17 0.35 0.33 0.16 0.29 0.31 0.34 0.38 0.23 MgO 48.69 46.07 48.67 49.19 48.72 49.36 49.27 49.47 49.40 49.63 CaO 0.03 0.31 0.02 0.11 0.17 0.13 0.12 0.02 0.06 0.14 Na 2 O 0.01 0.01 0.00 0.00 0.00 0.04 0.02 0.01 0.00 0.00 K 2 O 0.00 0.00 0.01 0.00 0.02 0.01 0.00 0.00 0.00 0.00 ∑ 100.30 101.24 100.28 100.50 99.53 101.02 100.81 101.01 100.64 100.57 apfu Si 1.005 1.003 0.999 0.995 1.002 1.000 0.998 0.996 0.000 0.000 0.000 0.000 Table 1 -Olivine (continued) SAI2 HEBRI2 D1 E1 E2 M3 F2 A1 D1 D2 A4 A5 neoblast neoblast neoblast neoblast neoblast porphyroclast core porphyroclast core porphyroclast rim neoblast neoblast wt% SiO 2 41.21 41.28 40.77 40.98 40.69 40.22 40.87 40.48 40.06 37.08 TiO 2 0.02 0.04 0.00 0.03 0.00 0.00 0.04 0.00 0.05 0.03 Al 2 O 3 0.00 0.01 0.05 0.00 0.02 0.03 0.02 0.02 0.03 0.01 Cr 2 O 3 0.00 0.06 0.01 0.00 0.01 0.05 0.01 0.01 0.00 0.00 FeO 9.90 9.69 9.94 10.03 9.04 10.36 11.09 10.51 10.49 10.46 MnO 0.20 0.11 0.16 0.16 0.15 0.16 0.16 0.15 0.22 0.12 NiO 0.34 0.41 0.36 0.39 0.39 0.36 0.37 0.35 0.32 0.39 MgO 48.70 49.10 49.14 48.74 50.33 48.61 48.66 48.52 45.67 52.00 CaO 0.07 0.07 0.04 0.06 0.17 0.06 0.06 0.10 0.05 0.08 Na 2 O 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.03 0.01 0.04 K 2 O 0.01 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.01 0.04 ∑ 100.45 100.78 100.46 100.39 100.81 99.85 101.30 100.18 96.92 100.24 apfu Si 1.006 1.004 0.996 1.002 0.985 0.990 0.995 0.994 Table 1 -Olivine (continued) HEBRI3 A6 C2 D3 G4 G5 G6 G1 G2 D3 E4 neoblast neoblast neoblast neoblast neoblast neoblast porphyroclast core porphyroclast rim neoblast neoblast wt% SiO 2 41.18 40.57 39.61 42.21 40.24 40.12 40.02 40.81 40.96 40.93 TiO 2 0.00 0.00 0.00 0.00 0.00 0.03 0.01 0.00 0.00 0.00 Al 2 O 3 0.03 0.02 0.05 0.00 0.04 0.00 0.03 0.03 0.00 0.00 Cr 2 O 3 0.00 0.06 0.01 0.04 0.00 0.02 0.02 0.00 0.03 0.00 FeO 10.37 10.65 10.59 11.03 11.01 10.89 9.92 9.77 9.82 9.65 MnO 0.15 0.15 0.11 0.18 0.16 0.17 0.14 0.15 0.15 0.09 NiO 0.37 0.35 0.39 0.31 0.35 0.29 0.31 0.38 0.40 MgO 48.29 48.61 50.40 47.86 48.28 48.26 49.06 49.19 49.50 49.15 CaO 0.05 0.05 0.18 0.06 0.07 0.10 0.06 0.05 0.05 0.06 Na 2 O 0.01 0.02 0.05 0.02 0.02 0.00 0.00 0.01 0.00 0.00 K 2 O 0.00 0.00 0.03 0.00 0.01 0.00 0.01 0.02 0.00 0.00 ∑ 100.43 100.52 101.38 101.79 100.14 99.93 99.57 100.34 100.89 100.28 apfu Si 1.007 0.993 0.956 1.020 0.990 0.989 0.985 0.997 Table 1 -Olivine (continued) Amp-bearing lherzolite HEBRI3 KAD5 F2 G3 G5 G6 D-1 D-2 E-4 E-5 E-13 E-14 neoblast neoblast neoblast neoblast porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim wt% SiO 2 41.33 40.59 40.58 40.90 39.69 39.92 40.32 40.85 39.99 40.09 TiO 2 0.03 0.00 0.00 0.00 0.00 0.01 0.03 0.01 0.00 0.00 Al 2 O 3 0.02 0.03 0.02 0.00 0.00 0.00 0.00 0.01 0.00 0.00 Cr 2 O 3 0.03 0.03 0.00 0.00 0.00 0.03 0.01 0.00 0.00 FeO 9.95 10.03 9.79 9.64 10.13 10.06 10.29 10.19 10.00 10.05 MnO 0.14 0.14 0.14 0.18 0.20 0.17 0.15 0.21 0.17 0.19 NiO 0.37 0.42 0.33 0.34 0.29 0.41 0.33 0.21 0.30 0.33 MgO 48.93 49.37 49.17 48.94 49.34 49.08 49.59 49.49 49.86 49.81 CaO 0.08 0.07 0.05 0.06 0.05 0.02 0.06 0.05 0.05 0.05 Na 2 O 0.01 0.00 0.02 0.02 0.03 0.02 0.00 0.02 0.00 0.04 K 2 O 0.01 0.00 0.01 0.01 0.00 0.00 0.00 0.00 0.01 0.00 ∑ 100.88 100.68 100.13 100.10 99.73 99.69 100.80 101.05 100.38 100.56 apfu Si 1.005 0.989 0.993 1.002 0.974 0.981 0.981 0.992 0.000 0.000 0.000 0.000 Table 1 -Olivine (continued) KAD5 G-1 G-2 L-8 L-9 D-3 D-4 D-5 D-6 D-9 E-3 porphyroclast core porphyroclast rim porphyroclast core porphyroclast rim neoblast neoblast neoblast neoblast neoblast neoblast wt% SiO 2 40.57 40.17 39.81 40.36 40.13 39.79 40.11 40.48 39.91 39.73 TiO 2 0.00 0.01 0.04 0.00 0.01 0.01 0.00 0.00 0.00 0.02 Al 2 O 3 0.03 0.00 0.00 0.03 0.00 0.03 0.00 0.00 0.00 0.00 Cr 2 O 3 0.01 0.00 0.00 0.00 0.04 0.00 0.00 0.04 0.01 0.00 FeO 10.01 10.20 10.33 10.14 10.20 10.34 10.17 10.13 10.37 10.19 MnO 0.14 0.17 0.19 0.13 0.21 0.14 0.20 0.13 0.22 0.20 NiO 0.37 0.29 0.34 0.42 0.29 0.34 0.27 0.29 0.31 0.41 MgO 49.10 49.09 49.69 49.52 49.92 49.48 44.91 49.19 50.13 49.91 CaO 0.04 0.05 0.03 0.05 0.05 0.05 0.07 0.03 0.05 0.05 Na 2 O 0.01 0.00 0.03 0.00 0.01 0.00 0.00 0.01 0.00 0.00 K 2 O 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 ∑ 100.27 100.00 100.45 100.65 100.86 100.18 95.74 100.32 101.02 100.52 apfu Si 0.992 0.985 0.971 0.983 0.974 0.973 1.028 0.000 0.000 0.000 Fe 2+ 0.160 0.161 0.154 0.170 0.190 0.219 0.204 0.208 0.212 0.217 Fe 3+ 0.047 0.047 0.050 0.038 0.019 0.002 0.013 0.014 0.008 0.005 Mn 0.002 0.004 0.004 0.002 0.002 0.004 0.003 0.003 0.003 0.003 Ni 0.008 0.005 0.009 0.007 0.006 0.007 0.007 0.005 0.007 0.007 Mg 1.803 1.804 1.804 1.798 1.789 1.765 1.775 1.770 1.771 1.768 Ca 0.001 0.001 0.001 0.002 0.001 0.002 0.002 0.002 0.002 0.002 Na 0.001 0.000 0.001 0.001 0.001 0.001 0.002 0.002 0.000 0.000 K 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.990 0.000 Table 1 -Olivine (continued) KAD5 KAD14 E-10 F-8 F-14 L-3 L-11 A1 A5 B4 C1 A2 neoblast neoblast neoblast neoblast neoblast porphyroclast core porphyroclast core porphyroclast core porphyroclast core porphyroclast rim wt% SiO 2 39.88 39.95 40.17 40.25 40.53 40.81 40.45 40.64 40.07 40.48 TiO 2 0.05 0.01 0.00 0.01 0.01 0.04 0.00 0.01 0.00 0.00 Al 2 O 3 0.01 0.02 0.00 0.04 0.00 0.07 0.04 0.03 0.05 0.03 Cr 2 O 3 0.00 0.02 0.03 0.00 0.01 0.00 0.04 0.00 0.09 FeO 10.13 10.20 10.04 10.25 10.22 10.80 10.57 10.85 10.56 10.79 MnO 0.12 0.19 0.21 0.10 0.10 0.22 0.13 0.15 0.13 0.16 NiO 0.40 0.28 0.48 0.37 0.33 0.35 0.33 0.27 0.36 0.33 MgO 49.42 49.55 49.85 49.52 49.12 48.45 48.49 48.59 47.87 48.17 CaO 0.03 0.05 0.05 0.06 0.04 0.08 0.07 0.09 0.07 0.08 Na 2 O 0.03 0.00 0.01 0.01 0.02 0.01 0.03 0.04 0.00 0.00 K 2 O 0.00 0.01 0.03 0.01 0.00 0.00 0.00 0.01 0.00 0.00 ∑ 100.08 100.28 100.87 100.62 100.38 100.82 100.16 100.68 99.20 100.05 apfu Si 0.976 0.976 0.975 0.980 0.991 0.998 0.993 0.000 0.002 0.000 0.994 0.001 Table 1 -Olivine (continued) KAD14 A6 B5 C2 A3 A4 B2 D5 I3 I4 porphyroclast rim porphyroclast rim porphyroclast rim neoblast neoblast neoblast neoblast neoblast neoblast wt% SiO 2 40.27 40.14 39.97 40.14 40.40 40.52 40.79 40.96 40.87 TiO 2 0.00 0.01 0.05 0.00 0.00 0.00 0.04 0.00 0.06 Al 2 O 3 0.06 0.03 0.07 0.09 0.01 0.01 0.05 0.05 0.01 Cr 2 O 3 0.06 0.00 0.02 0.01 0.00 0.00 0.01 0.00 0.00 FeO 10.81 10.61 10.47 10.49 10.36 10.52 10.64 10.64 10.62 MnO 0.19 0.13 0.22 0.12 0.24 0.14 0.19 0.18 0.20 NiO 0.35 0.29 0.47 0.36 0.30 0.24 0.35 0.36 0.33 MgO 48.13 48.76 48.00 48.76 48.56 48.18 48.62 48.49 48.21 CaO 0.10 0.08 0.07 0.07 0.09 0.08 0.07 0.09 0.08 Na 2 O 0.00 0.03 0.00 0.00 0.02 0.01 0.01 0.01 0.01 K 2 O 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.03 ∑ 99.97 100.07 99.34 100.03 100.00 99.71 100.77 100.79 100.42 apfu Si 0.993 0.985 0.991 0.986 0.993 1.000 0.997 Table 1 -Olivine (continued) Harzburgite
	∑ ∑ ∑ ∑ ∑ ∑ ∑ ∑ ∑ ∑ ∑ ∑ ∑ ∑ ∑ ∑ ∑ ∑ ∑	3.000 2.999 2.998 3.000 3.000 2.999 3.000 3.000 2.999 3.000 3.000 3.000 3.000 3.000 3.000 2.995 2.995 3.000 3.000	3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 2.982 3.000 3.000 2.786 3.000 2.993 3.000 3.000 3.000	3.000 3.000	3.000 3.000 3.000 2.993 2.990 3.000 3.000 3.000 3.000 3.000 3.000 2.789 3.000 3.000 3.000 3.000 3.000 3.000 3.000	3.000 3.000 3.000 3.000 3.000 3.000 2.999 3.000 3.000 2.788 3.000 3.000 2.999 3.000 3.000	2.998 3.000 3.000 3.000	3.000 2.864 3.000 2.997 3.000 3.000 2.998 3.000 3.000 2.791 3.000 2.997 3.000 3.000	3.000 3.000 3.000 3.000 3.000	3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000	2.998 3.000 3.000 3.000 3.000 3.000 3.000 3.000	2.997 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 2.972	3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000	3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000	3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000	2.996 3.000 3.000 2.988 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000	3.000 2.999 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000
	Fo Fo Fo Fo Fo Fo Fo Fo Fo Fo Fo Fo Fo Fo Fo Fo Fo Fo Fo	91 91 91 91 90 90 80 91 93 90 90 90 90 93 89 90 90 90 90	91 91 90 90 91 90 90 89 90 90 89 90 86 90 90 90	91	91 90	91 91 90 90 78 91 91 90 90 90 88 90 89 90 90 90	91	91 90	91 91 91 90 91 91 90 90 90 88 92 90 90 90 90	91 90 91 89	91 88 90 91 91 91 90 90 90 89 90 90 90 90	91 90 92 90 90	91 91 91 91 90 90 90 90 90 90 90	91 91 90 91 90 90 90 89	91 91 90 91 90 90 90 90 90 90 89	91 91 91 91 90 90 90 89	91 91 90 90 90 90 90 92 90 90 90	91 91 90 90 91 90 89	91	90 91 90 91 92 90 90 90	91 90 89 90 90 90 90 89 90 89	91	92 91 90 90 90 90 90 90	91 91 90 90 90 90 90 90 90 89

Table 1 -

 1 Olivine (continued)

	2

Table

	Table 1 -Olivine (continued) Table 1 -Olivine (continued)
		ZYA1 ZYA1
		ZYA1-C-6 ZYA1-F-3	ZYA1-C-6b ZYA1-F-4	ZYA1-C-10 ZYA1-H-5	ZYA1-C-12 ZYA1-I-3	ZYA1-C-13 ZYA1-L-2		ZYA1-D-3 ZYA1-L-4		ZYA1-D-4 ZYA1-L-6		ZYA1-E-5 ZYA1-L-8		ZYA1-E-6 ZYA1-L-9		ZYA1-E-7	5
		porphyroclast core neoblast neoblast	porphyroclast rim neoblast neoblast neoblast neoblast neoblast	neoblast neoblast neoblast	neoblast neoblast neoblast	neoblast neoblast neoblast	neoblast neoblast neoblast	neoblast neoblast neoblast	neoblast neoblast neoblast	neoblast neoblast
	wt% wt% wt%
	SiO 2 SiO 2 SiO 2	40.31 40.66 39.89	35.97 40.34	40.39	40.06 40.33	38.30	39.86 40.43	39.51	40.02 40.53	40.18	39.98 40.27	39.75	40.05 40.64	39.99	39.89 40.41	40.63	39.51 40.62	39.97	40.01	40.45
	TiO 2 TiO 2 TiO 2	0.00 0.00 0.00	0.02 0.00	0.03	0.00 0.02	0.00	0.00 0.01	0.00	0.01 0.00	0.00	0.00 0.00	0.03	0.00 0.07	0.00	0.00 0.00	0.04	0.00 0.00	0.02	0.00	0.00
	Al 2 O 3 Al 2 O 3 Al 2 O 3	0.02 0.00 0.00	1.28 0.01	0.00	0.00 0.03	0.01	0.00 0.00	0.01	0.02 0.00	0.00	0.04 0.02	0.00	0.02 0.01	0.00	0.01 0.01	0.03	0.00 0.03	0.03	0.01	0.01
	Cr 2 O 3 Cr 2 O 3 Cr 2 O 3	0.08 0.03 0.01	1.39 0.00	0.01	0.00 0.00	0.10	0.10 0.03	0.00	0.11 0.12	0.00	0.10 0.01	0.00	0.01 0.07	0.01	0.05 0.08	0.00	0.00 0.06	0.06	0.05	0.06
	FeO FeO FeO	9.91 9.49 9.60	9.45 9.72	9.39	9.33 9.67	9.66	9.65 9.98	9.95	9.37 9.57	9.77	9.80 9.86	9.87	9.77 9.44	9.94	9.96 9.33	9.35	9.50 9.34	10.13	9.67	9.36
	MnO MnO MnO	0.23 0.23 0.20	0.19 0.19	0.18	0.25 0.27	0.19	0.23 0.25	0.19	0.16 0.21	0.23	0.22 0.22	0.21	0.18 0.21	0.20	0.12 0.18	0.19	0.16 0.21	0.21	0.19	0.24
	NiO NiO NiO	0.37 0.19 0.38	0.13 0.38	0.43	0.14 0.42	0.34	0.20 0.31	0.38	0.19 0.21	0.45	0.20 0.18	0.35	0.33 0.29	0.36	0.30 0.19	0.19	0.37 0.17	0.20	0.35	0.23
	MgO MgO MgO	49.60 49.67 49.51	42.92 49.71	49.50	49.87 49.25	47.79	48.69 49.31	48.69	49.02 49.06	48.88	49.18 46.10	48.91	49.16 49.76	48.90	47.25 49.71	48.55	53.71 50.05	48.81	49.64	49.31
	CaO CaO CaO	0.06 0.16 0.07	0.31 0.05	0.06	0.14 0.06	0.06	0.15 0.07	0.06	0.14 0.14	0.04	0.18 0.15	0.05	0.20 0.10	0.05	0.06 0.15	0.13	0.14 0.18	0.14	0.07	0.09
	Na 2 O Na 2 O Na 2 O	0.02 0.05 0.00	0.05 0.01	0.01	0.00 0.01	0.02	0.02 0.02	0.01	0.02 0.00	0.02	0.03 0.02	0.02	0.00 0.01	0.00	0.02 0.00	0.03	0.00 0.01	0.04	0.02	0.00
	K 2 O K 2 O K 2 O	0.00 0.00 0.00	0.10 0.02	0.01	0.00 0.00	0.00	0.02 0.00	0.03	0.00 0.01	0.00	0.01 0.00	0.01	0.00 0.00	0.01	0.00 0.00	0.01	0.01 0.00	0.01	0.00	0.00
	∑ ∑ ∑	100.61 100.48 99.66	91.81 100.41	100.01	99.79 100.06	96.48	98.92 100.41	98.84	99.06 99.84	99.56	99.74 96.83	99.20	99.73 100.60	99.47	97.66 100.06	99.15	103.40 100.66	99.62	100.02	99.75
	apfu apfu apfu
	Si Fe 2+ Fe 3+ Mn Ni Mg Ca Si Fe 2+ Fe 3+ Mn Ni Mg Ca Na K Si	0.982 0.166 0.036 0.005 0.007 1.800 0.002 0.990 0.170 0.023 0.005 0.004 1.802 0.004 0.003 0.000 0.979	0.969 0.213 0.000 0.004 0.003 1.723 0.009 0.002 0.003 0.983	0.988 0.169 0.024 0.004 0.008 1.804 0.002	0.980 0.150 0.041 0.005 0.003 1.818 0.004 0.000 0.000 0.988	0.972 0.150 0.055 0.004 0.007 1.807 0.002	0.987 0.175 0.025 0.005 0.004 1.797 0.004 0.001 0.001 0.987	0.980 0.164 0.042 0.004 0.008 1.799 0.002	0.988 0.172 0.022 0.003 0.004 1.804 0.004 0.001 0.000 0.995	0.989 1.003 0.000 0.982 0.986 0.000 0.000 0.000 0.179 0.167 0.176 0.193 0.022 0.037 0.029 0.000 0.005 0.004 0.004 0.004 0.009 0.007 0.007 0.004 1.794 1.800 1.796 1.786 0.001 0.001 0.001 0.000 0.000 0.981 0.984 1.003 0.002 0.000 0.001 0.166 0.169 0.210 0.036 0.032 0.000 0.004 0.004 0.003 0.004 0.007 0.006 1.799 1.799 1.771 0.005 0.005 0.002 0.001 0.000 0.001 0.000 0.000 0.000 1.019 0.988 0.000 0.000 0.000	0.000 0.037 0.149 0.003 0.007 1.875 0.003 0.000 0.000 0.000	0.001 0.177 0.032 0.004 0.004 1.791 0.000	0.001 0.155 0.043 0.004 0.007 1.809 0.002 0.001 0.000	0.001 0.178 0.014 0.005 0.004 1.803 0.000
	∑ ∑ ∑	3.000 3.000 3.000	2.998 3.000	3.000	3.000 3.000	3.000	3.000 3.000	3.000	3.000 3.000	3.000	3.000 2.981	3.000	3.000 3.000	3.000	2.997 3.000	2.997	3.000 3.000	3.000	3.000	3.000
	Fo Fo Fo	90 90 90	89 90	90	90 90	90	90 90	90	90 90	90	90 89	90	90 90	90	89 90	90	91 91	90	90	90

Table 1 -

 1 Olivine (continued)

	6

Table 1 -

 1 Olivine (continued)

	2

Table 2 -

 2 Orthopyroxene (continued)

	4

Table 2 -

 2 Orthopyroxene (continued)

	-D7

Table 2 -

 2 Orthopyroxene (continued)

	2

Table

Table 2 -

 2 Orthopyroxene (continued)

	2

Table 2 -

 2 Orthopyroxene (continued)

	1

Table 2 -

 2 Orthopyroxene (continued)

	4

Table

Table 3 -

 3 Clinopyroxene (continued)

	5

Table 7 -

 7 Clinopyroxene trace element (continued)

	-20031CPXA5B	07-20031CPXA5

Table 7 -

 7 Clinopyroxene trace element (continued)

	Harzburgite

Table 7 -

 7 Clinopyroxene trace element (continued)

	Ol-websterite

Table 7 -

 7 Clinopyroxene trace element (continued)

	Grt-free pyroxenite

Table 12 -

 12 Radiogenic isotopic data

	Pyroxenite
	Grt-websterite	Nd (ppm)	143 Nd/ 142 Nd	1!	Sr (ppm)	86 Sr/ 87 Sr	1!
	TAK3 -Cpx	6.3	0.513253	0.000003	101	0.703113	0.000004
	TAK3 -Grt	0.42	0.513302	0.00001	0.19	0.703329	0.000023
	TAK5 -Cpx	2.7	0.51305	0.000003	45.1	0.702739	0.000004
	TAK6 -Cpx	4.2	0.512966	0.000004	110	0.703193	0.000004
	TAK8 -Cpx	2.6	0.513086	0.000003	149	0.703342	0.000004
	TAK9 -Cpx	3.2	0.513182	0.000003	68.8	0.70304	0.000004
	TAK10 -Cpx	3.1	0.513051	0.000004	78.1	0.703229	0.000004
	TAK12 -Cpx	2.5	0.513033	0.000005	85.4	0.703043	0.000004
	IBA21c -Cpx	2.8	0.513195	0.000004	55.8	0.702909	0.000004
	Ol-websterite
	TAK7 -Cpx	4.4	0.51307	0.000003	69.8	0.702981	0.000005
	TAK7 -Ol
	TAK13 -Cpx	3.7	0.512904	0.000003	139	0.702508	0.000004
	TAK 13 -Ol
	TAK17 -Cpx	3.9	0.512908	0.000004	138	0.702507	0.000005
	TAK17 -Ol
	Grt-clinopyroxenite
	TAK4 -Cpx	4.3	0.512865	0.000004	205	0.703166	0.000004
	TAK4 -Grt	0.53	0.512865	0.000015	5.2
	Clinopyroxenite
	BOU4 -Cpx	13.2	0.51284	0.000003	141	0.703963	0.000004
	Lherzolite
	KAD1	3.8	0.513135	0.000005	45.8	0.702695	0.000004
	2003-1	4.4	0.51334	0.000003	74.0	0.702405	0.000004
	HEBRI3	4.5	0.513128	0.000004	103	0.702799	0.000005

Figure 5.16A and B -Chondrite-normalized REE (A) and incompatible trace element patterns (B) for clinopyroxenes from Morocco type 1 websterite[START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF].

Bousera these pyroxenites could represent old mafic rocks that they have been isolated in the subcontinental lithospheric mantle for very long time spans. On this ground, the fragments of oceanic material and the crustal components recorded by pyroxenites may be tentatively related to subduction processes occurred during Pan-African times (Neoproterozoic).If so, these pyroxenites maintained for long time their pristine geochemical signatures withourt marked changes, which are expected at least for stable isotopes (and particularly Li). An alternative interpretation to be still explored is that these pyroxenites contain crust-derived components involved in or released from recent (<85 ma) subduction processes occurred in western Mediterranean. According to several Authors[START_REF] Gelabert | A new proposal for the late Cenozoic geodynamic evolution of the western Mediterranean[END_REF][START_REF] Duggen | Deep roots of the Messinian salinity crisis[END_REF][START_REF] Duggen | Post-collisional transition from subduction-to intraplate-type magmatism in the westernmost Mediterranean: evidence for the continental-edge delamination of subcontinental lithosphere[END_REF] 2009; see Chapter 1; § 1.1.1), subduction processes started since the late Cretaceous and developed until 10-8 ma, when slab rollback and continental age delamination caused subduction suction. In this scenario, fragments of oceanic crust could have been temporarely stored in the lithosphere before their uptake by plume-related Plio-Quaternary alkaline lavas that brought them to the surface.

0.995 0.997 Ti 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 Al 0.000 0.000 0.000 0.001 0.000 0.002 0.001 0.001 0.001 0.001 Cr 0.000 0.000 0.001 0.000 0.000 0.000 0.989 0.988 Ti 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.001 Al 0.001 0.000 0.000 0.001 0.001 0.000 0.000 0.001 0.000 0.000 Cr 0.000 0.001 0.001 0.002 0.000 0.002 0.000 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 K 0.000 0.000 0.000 0.000 0.000 0.000 0.984 0.992 Ti 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.001 0.000 0.000 Al 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.000 Cr 0.001 0.000 0.002 0.000 0.004 0.004 0.002 Na 0.001 0.000 0.001 0.000 0.001 0.001 0.000 0.001 0.002 0.000 K 0.000 0.000 0.000 0.001 0.000 0.000 0.925 0.978 Ti 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Al 0.000 0.041 0.000 0.000 0.001 0.001 0.001 0.000 0.000 0.000 Cr 0.001 0.030 0.000 0.002 0.002 0.983 0.989 Ti 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Al 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 Cr 0.001 0.000 0.000 0.000 0.004 0.006 0.001 Na 0.001 0.000 0.000 0.000 0.000 0.002 0.000 0.000 0.000 0.001 K 0.000 0.000 0.000 0.000 0.000 0.000

 [START_REF] Raffone | Metasomatism in the lithospheric mantle beneath Middle Atlas, (Morocco) and the origin of Fe-and Mg-rich wehrlites[END_REF]