Federico Rossetti
email: federico.rossetti@uniroma3.ittel

Riccardo Asti

Claudio Faccenna

Axel Gerdes

Federico Lucci

Thomas Theye

Magmatism and crustal extension: constraining activation of the ductile shearing along the Gediz detachment, Menderes Massif (western Turkey)

Keywords: extensional tectonics, magmatism, mylonite shearing, thermobarometry, U-Pb geochronology, Menderes Massif, Turkey

The Menderes Massif of western Turkey is a key area to study feedback relationships between magma generation/emplacement and activation of extensional detachment tectonics. Here, we present new textural analysis and in situ U-(Th)-Pb titanite dating from selected samples collected in the transition from the undeformed to the mylonitized zones of the Salihli granodiorite at the footwall of the Neogene, ductile-to-brittle, top-to-the-NNE Gediz-Alaşheir (GDF) detachment fault. Ductile shearing was accompanied by the fluid-mediated sub-solidus transformation of the granodiorite to orthogneiss, which occurred at shallower crustal levels and temperatures compatible with the upper greenschist-to-amphibolite facies metamorphic conditions (530-580 °C and P<2 GPa). The syn-tectonic metamorphic overgrowth of REE-poor titanite on pristine REE-rich igneous titanite offers the possibility to constrain the timing of magma crystallisation and solid-state shearing at the footwall of the Gediz detachment. The common Pb corrected 206 Pb/ 238 U ( 206 Pb*/ 238 U) ages and the REE re-distribution in titanite that spatially correlates with the Th/U zoning suggests that titanite predominantly preserve opensystem ages during fluid-assisted syn-tectonic re-crystallisation in the transition from magma crystallization and emplacement (at ~16-17 Ma) to the syn-tectonic, solid-state shearing (at ~14 Ma). A minimum time lapse of ca. 1-2 Ma is then inferred between the crustal emplacement of the Salihli granodiorite and nucleation of the ductile extensional shearing along the Gediz detachment. The reconstruction of the cooling history of the Salihli granodiorite documents a punctuated evolution dominated by two episodes of rapid cooling, between ~14 Ma and ~12 Ma (~100 °C/Ma) and between ~3 and ~2 Ma (~105 °C/Ma). We relate the first episode to nucleation and development of post-emplacement of ductile shearing along the GDF and the second to brittle high-angle faulting, respectively. Our dataset suggests that in the Menderes Massif the activation of ductile extension was a consequence, rather than the cause, of magma emplacement in the extending crust.

Introduction

Detachment faults are high-strain, ductile-to-brittle, low-angle extensional shear zones, typically constituted by an upper cataclastic or ultracataclastic horizon, underlain by a ductile, hundreds of meters thick, mylonitic to ultramylonitic zone (e.g. [START_REF] Lister | The origin of metamorphic core complexes and detachment faults formed during Tertiary continental extension in the northern Colorado River region, USA[END_REF]. When exposed at the surface, these shear zones generally separate a non-metamorphosed or slightly metamorphosed hanging wall, from a higher grade metamorphic footwall, also known as metamorphic core complexes (e.g. Crittenden et al., 1980;Davis and Coney, 1989;[START_REF] Davis | Fault and fault-rock characteristics associated with Cenozoic extension and core-complex evolution in the Catalina-Rincon region, southeastern Arizona[END_REF]Gautier and Brun, 1994;[START_REF] Famin | Evolution of hydrothermal regime along a crustal shear zone, Tinos Island, Greece[END_REF]Lister et al., 1984;[START_REF] Wernike | Uniform-sense normal simple shear of the continental lithosphere[END_REF]Whitney et al., 2013 and references therein). The role of magmatism in core complex formation and, more in general, in the activation of ductile extensional tectonics is still debated. In particular, it is a key issue to understand whether is magmatism that facilitates detachment faulting (and core complex formation in general) or the other way around, because despite extension-driven decompression may cause melting, melting itself may promote and guide the extensional process (e.g. [START_REF] Corti | Analogue modelling of continental extension: a review focused on the relations between the patterns of deformation and the presence of magma[END_REF][START_REF] Laurent | Interrelations between extensional shear zones and synkinematic intrusions: The example of Ikaria Island (NE Cyclades, Greece)[END_REF]Parson and Thompson 1993;[START_REF] Teyssier | Gneiss domes and orogeny[END_REF][START_REF] Whitney | Continental and oceanic core complexes[END_REF]. In particular, crustal heating induced by pluton emplacement at shallow depths may generate a time-dependent variation in the rheological properties of the crust by causing an upward migration of the (regional) brittle-ductile transition and allowing shear strain localization facilitated by thermal softening [START_REF] Caggianelli | Post-emplacement thermorheological history of a granite intrusion and surrounding rocks: the Monte Capanne pluton, Elba Island, Italy[END_REF][START_REF] Jolivet | Ductile extension and the formation of the Aegean sea[END_REF][START_REF] Lister | Plutonism and the origin of metamorphic core complexes[END_REF][START_REF] Rabillard | Interactions between plutonism and detachments during metamorphic core complex formation, Serifos Island (Cyclades, Greece)[END_REF]. The thermal softening induced by magmatism may also facilitates the slip on low-angle normal faults by inducing rotation of the principal stresses [START_REF] Parsons | Does magmatism influence low-angle normal faults?[END_REF]. As a matter of fact, the general chronological relationship between the onset of extension and magmatism is not straightforward: it has been documented that one can alternatively pre-date the other, or these may even be synchronous (e.g. [START_REF] Aoya | Northsouth extension in the Tibetan crust triggered by granite emplacement[END_REF][START_REF] Jolivet | Cenozoic geodynamic evolution of the Aegean[END_REF][START_REF] Laurent | Interrelations between extensional shear zones and synkinematic intrusions: The example of Ikaria Island (NE Cyclades, Greece)[END_REF][START_REF] Lister | Plutonism and the origin of metamorphic core complexes[END_REF][START_REF] Metcalf | Introduction to special section: Magmatism and extension[END_REF][START_REF] Rabillard | Interactions between plutonism and detachments during metamorphic core complex formation, Serifos Island (Cyclades, Greece)[END_REF].

The Menderes Massif of western Turkey (Fig. 1) is a key area to study feedback relationships between Neogene magma generation/emplacement and activation of extensional detachment tectonics [START_REF] Bozkurt | Southern Menderes massif: an incipient metamorphic core complex in western Anatolia, Turkey[END_REF][START_REF] Çemen | Postcollisional extensional tectonics and exhumation of the Menderes massif in the Western Anatolia extended terrane, Turkey[END_REF][START_REF] Dilek | Syn-extensional granitoids in the Menderes core complex and the late Cenozoic extensional tectonics of the Aegean province[END_REF] , 2013;[START_REF] Glodny | Precise U-Pb ages of syn-extensional Miocene intrusions in the central Menderes Massif, western Turkey[END_REF]Hetzel et al., 1995a,b;[START_REF] Işik | Ductile-brittle transition along the Alaşehir detachment fault and its structural relationship with the Simav detachment fault, Menderes massif, western Turkey[END_REF][START_REF] Öner | Geology and geochemistry of the synextensional Salihli granitoid in the Menderes core complex, western Anatolia, Turkey[END_REF]Ring et al., 1995;Ring and Collins, 2005;[START_REF] Thomson | Thermochronologic evaluation of post-collision extension in the Anatolide Orogen, western Turkey[END_REF]. Pluton emplacement is commonly considered as syn-extensional (e.g. [START_REF] Dilek | Syn-extensional granitoids in the Menderes core complex and the late Cenozoic extensional tectonics of the Aegean province[END_REF]Erkül et al., 2013 and references therein;[START_REF] Işik | Ductile-brittle transition along the Alaşehir detachment fault and its structural relationship with the Simav detachment fault, Menderes massif, western Turkey[END_REF], but some uncertainty still persists on the timing of magma crystallization and ductile shearing [START_REF] Catlos | Geochemistry, geochronology, and cathodoluminescence imagery of the Salihli and Turgutlu granites (central Menderes Massif, western Turkey): implications for Aegean tectonics[END_REF]2011).

In this study, we report new mineralogical, petrographical observations and in situ U-(Th)-Pb titanite geochronology results from selected samples collected in the transition from the undeformed to the mylonitized zones of the early Miocene Salihli granodiorite at the footwall of the Gediz-Alaşheir detachment fault (Hetzel et al., 1995a;[START_REF] Işik | Ductile-brittle transition along the Alaşehir detachment fault and its structural relationship with the Simav detachment fault, Menderes massif, western Turkey[END_REF]Figs. 1 and 2; hereafter referred as GDF), documenting a minimum time lapse of ca. 1-2 Ma between magma crystallization/emplacement and activation of ductile shearing associated with the development of the GDF. We conclude that the Neogene extensional detachment tectonics was a consequence, rather than the cause, of magma emplacement in the Menderes Massif.

Geological background

The Menderes Massif of western Turkey (Fig. 1) is an Alpine extensional province, which has been affected by post-orogenic crustal stretching since the Oligocene-Miocene times as a part of the Tertiary Aegean extensional system (e.g. Gessner et al., 2001a;[START_REF] Jolivet | Exhumation of deep crustal metamorphic rocks and crustal extension in arc and back-arc regions[END_REF][START_REF] Erkül | Tectonic significance of synextensional ductile shear zones within the Early Miocene Alacamdag granites, northwestern Turkey[END_REF][START_REF] Jolivet | Cenozoic geodynamic evolution of the Aegean[END_REF]Ring et al., 2003;[START_REF] Thomson | Thermochronologic evaluation of post-collision extension in the Anatolide Orogen, western Turkey[END_REF]. The Menderes Massif consists of continental-derived basement nappes, currently interpreted as a metamorphic core complex (Menderes Metamorphic Core Complex, MMCC), whose exhumation was dominantly assisted by ductile-to-brittle extensional detachment tectonics and closely associated with emplacement of syn-tectonic granitoids and formation of supradetachment basins [START_REF] Bozkurt | Southern Menderes massif: an incipient metamorphic core complex in western Anatolia, Turkey[END_REF][START_REF] Bozkurt | Tectonic evolution of the Gediz Graben: field evidence for an episodic, two-stage extension in western Turkey[END_REF][START_REF] Dilek | Syn-extensional granitoids in the Menderes core complex and the late Cenozoic extensional tectonics of the Aegean province[END_REF][START_REF] Erkül | Petrology, mineral chemistry and Sr-Nd-Pb isotopic compositions of granitoids in the central Menderes metamorphic core complex: Constraints on the evolution of Aegean lithosphere slab[END_REF][START_REF] Glodny | Precise U-Pb ages of syn-extensional Miocene intrusions in the central Menderes Massif, western Turkey[END_REF]Hetzel et al., 1995a,b;Işık et al., 2003;[START_REF] Öner | Geology and geochemistry of the synextensional Salihli granitoid in the Menderes core complex, western Anatolia, Turkey[END_REF][START_REF] Öner | Supradetachment basin evolution during continental extension: the Aegean province of western Anatolia, Turkey[END_REF][START_REF] Thomson | Thermochronologic evaluation of post-collision extension in the Anatolide Orogen, western Turkey[END_REF].

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6 Indeed, the activity of the extensional detachment tectonics in the MMCC is chiefly constrained by the age of crystallization and cooling of the syn-extensional magmatism in the immediate footwall of the detachment faults. In particular, a two-stage extensional detachment tectonics has been reconstructed (Çemen et al., 2006). The early stage is associated with the activity of the early Miocene (~ 21-19 Ma) top-to the-N Simav detachment in the northern part of the Menderes Massif, as constrained by the syn-tectonic Alaçamdağ magmatic suite (Bozkurt and Satır, 2000;[START_REF] Erkül | Tectonic significance of synextensional ductile shear zones within the Early Miocene Alacamdag granites, northwestern Turkey[END_REF][START_REF] Işik | Ductile-brittle transition along the Alaşehir detachment fault and its structural relationship with the Simav detachment fault, Menderes massif, western Turkey[END_REF]Ring and Collins, 2005). The second stage is associated with the middle Miocene activity of the north-dipping Gediz and the southdipping Büyük Menderes detachment faults, associated with the emplacement and ductile shearing of the Salihli and Turgutlu granodiorites in the central part of the Menderes Massif [START_REF] Glodny | Precise U-Pb ages of syn-extensional Miocene intrusions in the central Menderes Massif, western Turkey[END_REF]Hetzel et al., 1995;[START_REF] Lips | Multistage exhumation of the Menderes Massif, western Anatolia (Turkey)[END_REF] (Figs. 1 and2). Geochemical signatures of the syn-tectonic granitoids document for I-and S-type magmatism, derived from heterogeneous sub-continental lithospheric mantle sources [START_REF] Catlos | Geochemistry, geochronology, and cathodoluminescence imagery of the Salihli and Turgutlu granites (central Menderes Massif, western Turkey): implications for Aegean tectonics[END_REF][START_REF] Dilek | Syn-extensional granitoids in the Menderes core complex and the late Cenozoic extensional tectonics of the Aegean province[END_REF][START_REF] Erkül | Magma interaction processes in syn-extensional granitoids: the Tertiary Menderes metamorphic core complex, western Turkey[END_REF][START_REF] Erkül | Petrology, mineral chemistry and Sr-Nd-Pb isotopic compositions of granitoids in the central Menderes metamorphic core complex: Constraints on the evolution of Aegean lithosphere slab[END_REF]Oner et al., 2010) with a strong crustal fingerprint [START_REF] Altunkaynak | Spatial, temporal and geochemical evolution of Oligo-Miocene granitoid magmatism in western Anatolia, Turkey[END_REF]. Igneous thermobarometry documents shallow crustal emplacement conditions for the Miocene granitoids, with crystallization temperatures ranging 700-800°C over 0.2-0.3 GPa [START_REF] Catlos | Geochemistry, geochronology, and cathodoluminescence imagery of the Salihli and Turgutlu granites (central Menderes Massif, western Turkey): implications for Aegean tectonics[END_REF][START_REF] Erkül | Petrology, mineral chemistry and Sr-Nd-Pb isotopic compositions of granitoids in the central Menderes metamorphic core complex: Constraints on the evolution of Aegean lithosphere slab[END_REF].

The Miocene Turgutlu and Salihli granitoids outcrop at the footwall of the NNE dipping GDF (e.g. [START_REF] Erkül | Petrology, mineral chemistry and Sr-Nd-Pb isotopic compositions of granitoids in the central Menderes metamorphic core complex: Constraints on the evolution of Aegean lithosphere slab[END_REF][START_REF] Glodny | Precise U-Pb ages of syn-extensional Miocene intrusions in the central Menderes Massif, western Turkey[END_REF]Hetzel et al., 1995a;[START_REF] Işik | Ductile-brittle transition along the Alaşehir detachment fault and its structural relationship with the Simav detachment fault, Menderes massif, western Turkey[END_REF], a ductile-to-brittle gently dipping (~20°) extensional fault that separates the crystalline rocks of the MMCC at the footwall, from the supradetachment Neogene deposits of the Gediz Graben at the hanging wall (e.g. Gessner et al., 2001a;Hetzel et al., 1995a,b;[START_REF] Işik | Ductile-brittle transition along the Alaşehir detachment fault and its structural relationship with the Simav detachment fault, Menderes massif, western Turkey[END_REF][START_REF] Öner | Supradetachment basin evolution during continental extension: the Aegean province of western Anatolia, Turkey[END_REF]) (Fig. 2). The crystallization age of these granodioritic intrusions is constrained to the middle Miocene, based on TIMS U-Pb dating of monazite (16.1±0.2 Ma; Turgutlu) and allanite (15.0±0.3 Ma; Salihli) aliquots [START_REF] Glodny | Precise U-Pb ages of syn-extensional Miocene intrusions in the central Menderes Massif, western Turkey[END_REF]. The 40 Ar/ 39 Ar biotite ages of 13.1±0.2 Ma from Turgutlu and 12.2±0.4 Ma from Salihli indicate slow cooling and continuous deformation to the late Miocene [START_REF] Glodny | Precise U-Pb ages of syn-extensional Miocene intrusions in the central Menderes Massif, western Turkey[END_REF]Hetzel et al., 1995a,b). A relatively wide range of ages spanning between 21.7 ± 4.5 and 9.6 ± 1.6 Ma was obtained through in situ

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ACCEPTED MANUSCRIPT

7 ion microprobe monazite Th-Pb dating from the Salihli granodiorite [START_REF] Catlos | Monazite geochronology, magmatism and extensional dynamics within the Menderes massif, Western Turkey[END_REF][START_REF] Catlos | Geochemistry, geochronology, and cathodoluminescence imagery of the Salihli and Turgutlu granites (central Menderes Massif, western Turkey): implications for Aegean tectonics[END_REF].

The youngest among these ages, obtained from a monazite grain located in the outer edge of an altered plagioclase crystal, was interpreted as a deformation age, rather than a crystallization age, also suggesting that this range of ages most likely dates episodes of deformation and tectonic exhumation [START_REF] Catlos | Geochemistry, geochronology, and cathodoluminescence imagery of the Salihli and Turgutlu granites (central Menderes Massif, western Turkey): implications for Aegean tectonics[END_REF]. 40 Ar/ 39 Ar dating of syn-kinematic white micas from the top of the detachment fault zone yielded ages of 7 ± 1 Ma [START_REF] Lips | Multistage exhumation of the Menderes Massif, western Anatolia (Turkey)[END_REF], interpreted as the time when the shear zone crossed the brittle-ductile transition [START_REF] Glodny | Precise U-Pb ages of syn-extensional Miocene intrusions in the central Menderes Massif, western Turkey[END_REF]. Finally, low-temperature thermochronology data (zircon (ZFT) and apatite (AFT) fission track and zircon (ZHe) and apatite (AHe) U-Th/He dating) on the Salihli granodiorite at the footwall of the GDF documents a Messinian-Pliocene (starting at c. 4-6 Ma) event of rapid cooling, slowing down after 2 Ma [START_REF] Buscher | Quantifying rates of detachment faulting and erosion in the central Menderes massif (western Turkey) by thermochronology and cosmogenic 10Be[END_REF].

For what concerns the upper-plate of the GDF, the sedimentary record of the Gediz Graben indicates that activity of the GDF was pulsed and hence the region experienced episodes of pulsed extension [START_REF] Bozkurt | Tectonic evolution of the Gediz Graben: field evidence for an episodic, two-stage extension in western Turkey[END_REF]Purvis and Robertson, 2005). Recently, new detrital AFT ages are made available from the basal sedimentary sequences filling the Gediz

Graben, which provided central ages of 16 ± 1.4 Ma [START_REF] Asti | Unraveling supradetachment basin evolution by detrital apatite fission track analysis: the Gediz Graben (Menderes Massif, Western Turkey)[END_REF]. This evidence attests that Middle Miocene is the maximum age for the beginning of sedimentation in the Gediz Graben, as already suggested by Ҫiftçi and [START_REF] Çiftçi | Evolution of the Miocene sedimentary fill of the Gediz Graben, SW Turkey[END_REF].

Methods

To constrain the age of activation of ductile shearing along the GDF, textural and petrographic observations were carried out in selected S-L tectonites developed at the expenses of the Salihli granodiorite and sampled along a structural transect running sub-parallel to the main NE-trending stretching direction (Fig. 2). Representative samples were chosen for the U- Details on the analytical methods and protocols adopted in this study are provided in the Appendix. Mineral compositions and representative chemical formulae are provided in the supplementary material. In the following, mineral abbreviations are after [START_REF] Whitney | Abbreviations for names of rock-forming minerals[END_REF].

Structures, textures and petrography

The GDF is exposed over an along-strike distance of more than 80 km along the southern margin of the Gediz graben, where it consists of a NNE dipping, flat-lying (10° to 30° dip) ductile-to-brittle shear zone with variable thickness (generally not exceeding ~100 m) (Figs. 1 and2). Eastward, the shear zone bends NS, striking sub-parallel to the main stretching direction (Fig. 2b). The shear zone formed at the expenses of the Miocene Salihli granodiorite and consists of a basal (up to 50 m thick) mylonite that gradually transition upward into cataclastic and ultracataclasitic fault rocks [START_REF] Buscher | Quantifying rates of detachment faulting and erosion in the central Menderes massif (western Turkey) by thermochronology and cosmogenic 10Be[END_REF][START_REF] Catlos | Linking microcracks and mineral zoning of detachment-exhumed granites to their tectonomagmatic history: Evidence from the Salihli and Turgutlu plutons in western Turkey (Menderes Massif)[END_REF]Hetzel et al., 1995a;[START_REF] Işik | Ductile-brittle transition along the Alaşehir detachment fault and its structural relationship with the Simav detachment fault, Menderes massif, western Turkey[END_REF]. Shear sense criteria systematically point to top-to-the-NNE (i.e. dip-slip) sense of shear, in a continuum from ductile-to-brittle deformation conditions (see also [START_REF] Buscher | Quantifying rates of detachment faulting and erosion in the central Menderes massif (western Turkey) by thermochronology and cosmogenic 10Be[END_REF]Hetzel et al., 1995a;[START_REF] Işik | Ductile-brittle transition along the Alaşehir detachment fault and its structural relationship with the Simav detachment fault, Menderes massif, western Turkey[END_REF].

The study area corresponds to the south-eastern portion of the GDF (Figs. 1 and2). Our samples are from the high strain domains (Fig. 2c), corresponding to the protomylonitic (T14-09)

and mylonitic (T14-06, T14-08 and T14-10) zones. At the meso-scale, protomylonites consist of light, medium-to-fine-grained rocks typified by variably-developed secondary, sub-horizontal foliation outlined by quartz-biotite folia with variable proportions of feldspar porphyroclasts (Fig. 3a). Igneous textures are commonly well preserved. Magmatic mineralogy (see All,Ap,Ilm (up to 3% in vol.) and minor Zrc as accessory minerals (Fig. 3b). In the mylonitic zone, ductile shearing is responsible for the transformation of the original igneous texture into a plano-linear gneissic fabric (S-L tectonite), outlined by C-type shear bands (e.g. [START_REF] Berthé | Orthogneiss, mylonite and non coaxial deformation of granites: the example of the South Armorican Shear Zone[END_REF][START_REF] Gapais | Shear structures within deformed granites: mechanical and thermal indicators[END_REF][START_REF] Passchier | Microtectonics[END_REF] and pronounced porphyroclastic appearance (Fig. 4a). The stretching lineations attitude is dip-parallel and they are provided by Qz-Fsp-Bt ± Amp aggregates, trending between N20°E and N40°E (Fig. 2a). At the thin sections scale, shear foliation is defined by the preferred orientation of ribbon Qz, secondary plagioclase (Pl 2 ), amphibole (Amp 2 ) and biotite (Bt 2 ), that together with Ep (X Fe [Fe 3+ /(Fe 3+ +Al 3+ )]= 0.14-0.17) and secondary titanite (Ttn 2 ) define penetrative oblique foliations with respect to C surfaces (Fig. 4). Tectonic foliations wrap around Fsp porphyroclasts to produce augen, which typically show a σ-type geometry with the sense of shear indicating topto-the-NNE (Figs. 3b-d). Ttn 1 grains also form σ-shaped porphyroclasts and occurs as boudinaged and stretched grains within the shear foliation (Fig. 4c). Feldspar porphyroclasts commonly show recrystallized grains at their boundaries, producing a core-and-rim structure diagnostic of dynamic recrystallization, compatible with medium-to high-grade temperature conditions (600-400 °C) during deformation (e.g., [START_REF] Gapais | Shear structures within deformed granites: mechanical and thermal indicators[END_REF][START_REF] Leloup | The Ailao Shan-Red River shear zone (Yunnan, China), Tertiary transform boundary of Indochina[END_REF][START_REF] Passchier | Microtectonics[END_REF]. Myrmekite growth along the boundaries of K-Fsp porphyroclasts and albite flame pertites suggests a fluid-assisted deformation under medium-grade temperature conditions (400-600 °C) [START_REF] Menegon | Ductile deformation of granitic rocks: selected examples from the Western Alps[END_REF][START_REF] Passchier | Microtectonics[END_REF]. Albite-rich Pl 2 also commonly occur as rims of Pl 1 (Fig. 4d). Bent twin lamellae, undulose extinction, and microfracturing suggest deformation under lower-grade temperature conditions (300-400 °C; e.g., [START_REF] Passchier | Microtectonics[END_REF] (Fig. 4d). Quartz shows dynamic recrystallization, dominantly assisted by subgrain rotation that resulted in pronounced grain size reduction (average grain size of 20 µm in the higher strain domains). Healed textures are also observed with evidence of static recrystallization accommodated by grain boundary migration (Figs. 4b-d). These structures are typical at medium-to high-grade conditions (600-400 °C; [START_REF] Drury | Deformation related recrystallization processes[END_REF][START_REF] Drury | Deformation related recrystallization processes[END_REF][START_REF] Hirth | Dislocation creep regimes in quartz aggregates[END_REF][START_REF] Passchier | Microtectonics[END_REF]Stipp et al., 2002). Quartz grains also exhibit undolose extinction

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and subgrain formation typical of strain-enhanced low-grade conditions (below 300 °C; [START_REF] Passchier | Microtectonics[END_REF]. Igneous biotite and amphibole porpyroclasts usually form asymmetric "fishes" aligned along the stretching lineation (Fig. 4f). Primary Bt 1 also shows undolose extinction and, in some samples, kink folding, attesting for deformation temperature below 250 °C [START_REF] Passchier | Microtectonics[END_REF].

Igneous plagioclase is characterized by anorthite-rich cores (X An 43-66%), showing both patchy and oscillatory compositional zoning, affected by corrosion and cracking (see also [START_REF] Catlos | Linking microcracks and mineral zoning of detachment-exhumed granites to their tectonomagmatic history: Evidence from the Salihli and Turgutlu plutons in western Turkey (Menderes Massif)[END_REF]. Outer cores consists of X An 31-35%, rimmed by thin albite-rich (X An 25-26%) overgrowth (Pl 2 ). Igneous Bt 1 is distinctly richer in TiO 2 (1.21-3.016 Al always minor than 0.81, corresponding to actinolite [START_REF] Leake | Nomenclature of amphiboles: Additions and revisions to the International MineralogicalAssociations amphibole nomenclature[END_REF] compositions.

Titanite microtextures and chemistry

Ttn makes up up to 1-2% of the rock and shows evidence of a polyphase crystallization, in a continuum from magma crystallization to solid-state, syn-metamorphic shear zone nucleation and development. Magmatic Ttn 1 occurs as isolated grains with euhedral, rhomboid to elongate and rounded shapes (300-500 µm across; Fig. 3b and5a). Magmatic origin is indicated by: (i) equilibrium textures with recrystallized magmatic Fsp-Qz-Amp-Bt assemblages (Figs. 3b and 5a-b); (ii) Ttn 1 inclusion in igneous Fsp and Amp 1 ; (iii) bright oscillatory and sector zoning in back-scattered electron (BSE) imaging (cfr. [START_REF] Wintsch | Foliation development and reaction softening by dissolution and precipitation in the transformation of granodiorite to orthogneiss, Glastonbury Complex, Connecticut[END_REF] (Fig. 5c); and

(iv) the pre-kinematic crystallisation relative to the shear foliation (Figs. 4d and5b).

Metamorphic Ttn 2 occurs within metamorphic foliation both as minute subhedral grains (10-30 µm across) associated and intergrowth with metamorphic Ep and fabric-forming secondary Bt 2 as the replacement products of igneous Bt 1 and Amp 1 in conjunction with Ep during syn-tectonic

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11 re-crystallisation (Fig. 5d). Metamorphic Ttn 2 also occurs as overgrowth onto magmatic Ttn 1 as outlined by uniform dark grey BSE domains that truncate oscillatory zoning patterns (Fig. 5c).

The two titanites types are chemically distinct (see

P-T conditions of shearing

The studied mylonitic shear zone developed at subsolidus conditions after crystallization of the Salihli granodiorite, at temperatures below 700-800 °C [START_REF] Catlos | Geochemistry, geochronology, and cathodoluminescence imagery of the Salihli and Turgutlu granites (central Menderes Massif, western Turkey): implications for Aegean tectonics[END_REF][START_REF] Erkül | Petrology, mineral chemistry and Sr-Nd-Pb isotopic compositions of granitoids in the central Menderes metamorphic core complex: Constraints on the evolution of Aegean lithosphere slab[END_REF]. The syn-kinematic assemblage made of Bt 2 -Qz-Pl 2 -Amp 2 -Ep-Ttn 2 made not possible the application of inverse multiequilibrium thermobarometry to constrain P-T conditions of shearing.

Inverse thermobarometry as based on the hornblende-plagioclase [START_REF] Anderson | The effect of temperature and oxygen fugacity on Al-inhornblende barometry[END_REF][START_REF] Holland | Non-ideal interactions in calcic amphiboles and their bearing on amphibole-plagioclase thermometry[END_REF] and the Ti-in-hornblende [START_REF] Otten | The origin of brown hornblende in the Artfjallet gabbro and dolerites[END_REF] thermometry and the temperature corrected Al-in-hornblende barometry [START_REF] Anderson | Status of thermobarometry in granitic batholiths[END_REF][START_REF] Anderson | The effect of temperature and oxygen fugacity on Al-inhornblende barometry[END_REF][START_REF] Schmidt | Amphibole composition in tonalite as a function of pressure: an experimental calibration of the Al-in-hornblende barometer[END_REF] as derived from compositions of both the magmatic and syn-tectonic assemblages are used here. The P-T estimates are obtained following the computation scheme provided in [START_REF] Anderson | Thermometers and thermobarometers in granitic systems[END_REF] and are shown in Table 2c. The Amph 1 compositions provide

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thermometry), in good agreement with P-T estimates calculated for Pl 1 -rims compositions (X An = 35%), which give P = 0.16-0.21 ± 0.06 GPa GPa at T = 590-632 ± 30 °C. Thermobarometry using Pl 1 -core compositions (X An = 66%) results in large uncertainty, suggesting no exchange equilibrium occurred between Pl l core and Amph 1 composition. The Amph 2 composition shows Al tot = 0.70-0.81 apfu that are near the lower limit of applicability of the horneblende-plagioclase thermobarometry [START_REF] Anderson | The effect of temperature and oxygen fugacity on Al-inhornblende barometry[END_REF], indicating very low P (< 0.1 GPa) at 570-578 ± 25 °C °C (Ti-in-Hbl), compatible with Pl-Hbl thermometry (531-556 ± 30 °C °C, for X An =25%

in Pl 2 ). These estimates are integrated with Zr-in-titanite thermometry [START_REF] Hayden | A thermobarometer for sphene (titanite)[END_REF]). The mean ZrO 2 content measured in Ttn 1 is 0.02 ± 0.01 wt% (1σ, n=57). Assuming a TiO 2 activity of 0.7 for rutile-free granitoids [START_REF] Hayden | A thermobarometer for sphene (titanite)[END_REF]) and a lithostatic pressure of 0.2 GPa, temperature estimates range 628-691 °C (Table 2d). The ZrO 2 content of Ttn 2 is systematically below the detection limit of the microprobe (< 0.01 wt%), attesting lower temperature conditions during the solid-state (syn-shearing) metamorphic overprint.

Collectively, the P-T conditions in the transition from magma crystallization and activation of ductile shearing along the GDF can be placed in the temperature windows of 530-690 °C for pressure around 0.2 GPa. In particular, the thermobaric environment for shear zone nucleation and development are placed at 530-580 °C for pressure below of ca. 0.2 GPa.

Assuming an average crustal density of 2700 kg/m 3 , this scenario conforms to an apparent paleogeothermal gradient of about 70-90 °C/km.

Titanite U-Pb geochronology

An in situ laser ablation induction-coupled mass spectrometry (LA-ICPMS) U-(Th)-Pb dating approach was adopted in this study to constrain age of shearing on selected samples from the protomylonitic (T14-09 sample) and mylonitic (T14-06 sample) zones of the GDF.

Analytical protocols and method adopted in this study are detailed in the Appendix. Analytical

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13 results are listed in Table 3. Plots and age calculations were made using the ISOPLOT4.1 software [START_REF] Ludwig | Isoplot/EX version 3.0, A geochronological toolkit for Microsoft Excel[END_REF]. Selected spots (n =180) of 30-43 µm in diameter show that titanites have variable concentrations of U (11-830 ppm) with generally low concentrations of radiogenic 206 Pb (0.02-3 ppm; mean: 0.5 ppm) and high common Pb (e.g. 63 to >99% of 206 Pb is common).

In the Tera-Wasserburg diagram, the measured, uncorrected, compositions of titanites cluster close to the Concordia for both samples, yielding nearly coincident lower intercept ages of 15.78 ± 0.64 Ma and 15.42 ± 0.39 Ma, for the proto-mylonitic (T14-09) and mylonitic (T14-06) sample, respectively (Fig. 6). Elevated MSWD of 2.0 (T14-09) and 3.2 (T14-06) indicate some scatter of the data, suggesting either disturbance of the isotope system or that the analysed Collectively, the common Pb corrected 206 Pb/ 238 U ( 206 Pb*/ 238 U) ages range from 18.1 ± 0.7 to 11.2 ± 0.7 Ma (Table 3) It is worth nothing that the 206 Pb*/ 238 U ages correlate with Th/U ratios and zoning domains in Ttn, with the oldest ages from the oscillatory zoned high Th/U domains and the youngest ages from the homogeneous overgrowth low Th/U domains, respectively (Fig. 7). Best fit Gaussian 206 Pb*/ 238 U age plots for the two samples consistently shows a bimodal distribution with peaks at 17.1 ± 0.2 Ma (73% of the data population; n = 54) and 14.4 ± 0.3 Ma (27% of the data population) and 16.1 ± 0.1 Ma (63% of the data population; n = 124) and 14.5 ± 0.1 Ma (37% of the data population), for sample T14-09 and T14-06, respectively (Figs. 6a-b).

Discussion

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14

The textural and petrographic features described in this study are compatible with a syntectonic, metamorphic overprint that operated below the solidus temperature of the Salihli granodiorite during transformation of the granodiorite to orthogneiss. In particular, taking into account (i) the syn-tectonic recrystallization of feldspar grains, suggesting deformation under high-to medium-grade temperature conditions (~600-400 °C) (Fig. 4), and (ii) the results from hornblende-plagioclase inverse thermobarometry (see Table 2c-d), ductile shearing and mylonite formation in the investigated rocks took place under retrograde conditions and was completed below 600 °C in a continuum from magma crystallisation to solid-state shearing that occurred at shallow crustal conditions and thermal environments indicative of the upper-greenschist to lower-amphibolite facies metamorphic conditions (climax T = ~600-500 °C).

Mylonitization was dominantly assisted by retrograde, fluid-mediated reactions at the expenses of the pristine igneous assemblage, during replacement of the main magmatic assemblage K-Fsp + Hb + Mg/Ilm and the syn-tectonic growth of Bt 2 -Ep-Qz±Pl 2 . This was associated with alkalis, Ca, Fe and Mg, H + , and SiO 2 mobility, mostly consequence of the alteration of the Amp-Fsp igneous assemblage (e.g., [START_REF] Aleinikoff | U-Pb geochronology of zircon and polygenetic titanite from the Glastonbury Complex, Connecticut, USA: an integrated SEM, EMPA, TIMS, and SHRIMP study[END_REF][START_REF] Wintsch | Foliation development and reaction softening by dissolution and precipitation in the transformation of granodiorite to orthogneiss, Glastonbury Complex, Connecticut[END_REF], and lost of the almost entire REE budget in the transition from Ttn 1 to Ttn 2 during structurally-controlled fluid flow. The occurrence of REE-rich magmatic (Ttn 1 ) and REE-poor metamorphic (Ttn 2 ) titanite in the same samples allows possibility to constrain time of magma crystallisation and solid-state shearing through U-Th-Pb geochronology. Distinction between magma crystallisation and shearing is challenging because the Ttn growth occurred in a narrow time lapse and in a temperature window (500-750°C) that is within the closure temperature interval of the U-Pb systematics [START_REF] Cherniak | Lead diffusion in titanite and preliminary results on the effects of radiation damage on Pb transport[END_REF][START_REF] Spencer | Campaign-style titanite U-Pb dating by laserablation ICP: Implications for crustal flow, phase transformations and titanite closure[END_REF] and therefore almost within limits of the method. Nonetheless, the fact that there is no evidence of common Pb Previously reported U-Pb TIMS ages of 16.1 ± 0.2 Ma (monazite, Turgutlu granodiorite) and 15.0 ± 0.3 Ma (allanite, Salihli granodiorite) [START_REF] Glodny | Precise U-Pb ages of syn-extensional Miocene intrusions in the central Menderes Massif, western Turkey[END_REF] are within uncertainty identical to our lower intercept U-Pb Ttn ages using spots of all analysed domains (Fig. 6). This suggests that the TIMS ages as our lower intercept ages dominantly record mixed ages, resulting from the analytical mixing of multiple (magmatic and metamorphic) age domains. We therefore propose that the bimodal distribution of the 206 Pb*/ 238 U Ttn ages (Fig. 6) records the transition from magma crystallization and emplacement (at ca. 16-17 Ma) to the syn-tectonic, solid-state recrystallisation (at ca. 14.5 Ma) of the Salihli granodiorite. A time lapse of about 1-2 Ma is therefore suggested between the crustal emplacement of the Salihli granodiorite and the activation of the ductile top-to-the-NNE extensional tectonics along the GDF.

Cooling history of the Salihli granodiorite: linking exhumation to extensional shearing

The rock microtextures attests for heterogeneous strain during progressive development of the shear zone fabrics along the GDF, from temperatures in the order of 400-600 °C down to low-grade conditions of <250 °C and hence from ductile-to-brittle-dominated shearing (see also [START_REF] Catlos | Linking microcracks and mineral zoning of detachment-exhumed granites to their tectonomagmatic history: Evidence from the Salihli and Turgutlu plutons in western Turkey (Menderes Massif)[END_REF]Hetzel et al., 1995a;[START_REF] Işik | Ductile-brittle transition along the Alaşehir detachment fault and its structural relationship with the Simav detachment fault, Menderes massif, western Turkey[END_REF]. Based on the results as obtained from the U-(Th)-Pb geochronology applied to the different (igneous and metamorphic) titanite 16 2008[START_REF] Erkül | Tectonic significance of synextensional ductile shear zones within the Early Miocene Alacamdag granites, northwestern Turkey[END_REF]Gessner et al., 2001;[START_REF] Glodny | Precise U-Pb ages of syn-extensional Miocene intrusions in the central Menderes Massif, western Turkey[END_REF]Hetzel et al., 1995a;2013;[START_REF] Lips | Multistage exhumation of the Menderes Massif, western Anatolia (Turkey)[END_REF]Ring et al., 2003), it is possible to reconstruct the time-temperature (T-t) evolution of the Salihli granodiorite at the footwall of the GDF (Fig. 8). In particular, the following key thermochronological constrains are assumed here: (i) cooling below 350 ± 50 °C [START_REF] Mcdougall | Geochronology and Thermochronology by the 40Ar/39Ar method[END_REF]) is placed at ~12 Ma based on Ar-Ar dating of biotite from the Salihli granodiorite (Hetzel et al., 1995a), and (ii) the final exhumation/cooling evolution below 260 ± 20 °C as constrained by the ZFT, AFT and the ZHe and AHe thermochronology [START_REF] Buscher | Quantifying rates of detachment faulting and erosion in the central Menderes massif (western Turkey) by thermochronology and cosmogenic 10Be[END_REF]Gessner et al., 2001a;Ring et al., 2003).

The reconstructed T-t diagram shows four distinct phases of cooling since the early/middle Miocene boundary, marked by different cooling rates and characterized by two episodes of enhanced cooling that both operated at rates of ~100°C/km, in the time lapse of 12-14 Ma and 2-3 Ma, respectively (Fig. 8). After ~12 Ma cooling rate dramatically decreased until ~5 Ma, with a mean value of 13 °C/Ma. This is followed by renewed cooling that culminated with the final episode starting at ~3 Ma. This final episode corresponds to the final exhumation event that drove the Salihli granodiorite and the GDF toward the surface (see also [START_REF] Buscher | Quantifying rates of detachment faulting and erosion in the central Menderes massif (western Turkey) by thermochronology and cosmogenic 10Be[END_REF].

Two major implications are derived from the reconstructed T-t history.

(1) The thermal perturbation associated with crystallisation, emplacement and onset of ductile deformation of the Salihli granodiorite in the crustal section of the MMCC was a long-lasting event that operated at temporal scales in the order of 10 6 years. Thermorheological modeling of the post-intrusive scenario in the crust predicts that the conditions for ductile deformation should last for a much shorter time interval, in the order of 10 4 -10 5 years (e.g., [START_REF] Caggianelli | Post-emplacement thermorheological history of a granite intrusion and surrounding rocks: the Monte Capanne pluton, Elba Island, Italy[END_REF]. A similar long-lasting thermal perturbation associated with granite emplacement in an extending crustal section has been documented in the Larderello geothermal field of Central Italy, where anomalous high gradient geothermal conditions were documented in the last 3 Ma, in concomitance with multiple granite intrusion ad depth [START_REF] Bertini | Geological structure of a long-living geothermal system, Larderello, Italy[END_REF]Dini et al., 2004;Rossetti et al., 2008). This suggests that the Miocene Salihli and Turgutlu granodiorites likely were

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the upper crustal apophyses of a deeper magma chamber responsible for the maintenance of a long-lasting regional positive thermal anomaly.

(2) The T-t diagram points to a pulsed nature of the cooling/exhumation history of the Salihli granodiorite, which also reflects the space-time rheological evolution (from ductile to brittle shearing) of the GDF. In particular, the reconstructed T-t evolution suggests that the transition from ductile to brittle behavior along the GDF did not occur as a continuous process, but was instead punctuated in time. Ductile, solid-state shearing is here placed in the 12-14 Ma time lapse, while an upper bound for the transition to brittle conditions along the GDF can be placed at ~7 ± 1 Ma, as derived from the 40 Ar/ 39 Ar dating of synkinematic white micas from the topmost horizons of the GDF [START_REF] Lips | Multistage exhumation of the Menderes Massif, western Anatolia (Turkey)[END_REF]) (Fig. 8). This is in line with the published low-T thermochronological data, showing that variations in the exhumation rates of the Salihli granodiorite have occurred in the last 5-6

Ma, ranging between 0.6 and 2.2 km/Ma [START_REF] Buscher | Quantifying rates of detachment faulting and erosion in the central Menderes massif (western Turkey) by thermochronology and cosmogenic 10Be[END_REF].

Similarly to many metamorphic core complexes [START_REF] Whitney | Continental and oceanic core complexes[END_REF], the last rapid cooling/exhumation phase (at rates in the order of 100 °C/Ma), starting at ~3 Ma, occurred when the footwall rocks of the GDF ascended to shallow crustal levels and normal faulting of the brittle upper crust, likely assisted by structurally-controlled fluid circulation (e.g. [START_REF] Morrison | Footwall refrigeration along a detachment fault: Implications for the thermal evolution of core complexes[END_REF], favored refrigeration of the exhuming footwall rocks.

Finally, it is worth noting that the composite exhumation model for the GDF and its delayed ductile (early-middle Miocene) to brittle (latest Miocene-Pliocene) activity as documented in this study is also compatible with the pulsed extension model proposed for the stratigraphic arrangement and structural evolution of the supradetachement Gediz Graben [START_REF] Altherr | A Late Oligocene/Early Miocene high temperature belt in the anti-cycladic crystalline complex (SE Pelagonian, Greece)[END_REF][START_REF] Bolhar | An integrated zircon geochronological and geochemical investigation into the Miocene plutonic evolution of the Cyclades, Aegean Sea, Greece: Part 1: Geochronology[END_REF][START_REF] Jolivet | Cenozoic geodynamic evolution of the Aegean[END_REF]Lee and Lister, 1992). Emplacement of the main Miocene Aegean granitoids occurred when the formation of metamorphic core complexes and ductile extensional deformation were already going on, as shown by the cases of Mykonos, Ikaria, Naxos, Paros and Serifos islands, where the intrusion of granitoids postdates the onset of migmatization and granitic bodies intruded older ductile extensional detachments (e.g. [START_REF] Brichau | Extensional faulting on Tinos Island, Aegean Sea, Greece: how many detachments?[END_REF][START_REF] Denèle | Granite intrusion in a metamorphic core complex: The example of the Mykonos laccolith (Cyclades, Greece)[END_REF][START_REF] Duchêne | Pressure-temperature-time evolution of metamorphic rocks from Naxos (Cyclades, Greece): constraints from thermobarometry and Rb/Sr dating[END_REF][START_REF] Laurent | Interrelations between extensional shear zones and synkinematic intrusions: The example of Ikaria Island (NE Cyclades, Greece)[END_REF][START_REF] Rabillard | Interactions between plutonism and detachments during metamorphic core complex formation, Serifos Island (Cyclades, Greece)[END_REF][START_REF] Seward | Cenozoic tectonic evolution of Naxos Island through a multifaceted approach of fission-track analysis[END_REF].

In the Menderes Massif, the onset of ductile extensional tectonics is constrained to the Early Miocene (21-22 Ma) by the activity of the Simav detachment fault and the syn-tectonic magmatism at the northern termination of the massif [START_REF] Çemen | Postcollisional extensional tectonics and exhumation of the Menderes massif in the Western Anatolia extended terrane, Turkey[END_REF][START_REF] Işik | Ductile-brittle transition along the Alaşehir detachment fault and its structural relationship with the Simav detachment fault, Menderes massif, western Turkey[END_REF]; Fig. 1). In the same region, stratigraphic evidence from the "NE-trending basins" (Selendi, Gördes, Demirci and Uşak basins; Fig. 1) attests that the Menderes basement rocks were already exhumed and exposed to erosion since the early-middle Miocene times (~14-21 Ma; [START_REF] Ercan | Batı Anadolu'daki Tersiyer ve Kuvaterner yaşlı volkanik kayaçlarda yeni yapılan radyometrik yaş ölçümlerinin yorumu [Some new radiometric ages from Tertiary and Quaternary volcanic rocks from West Anatolia[END_REF][START_REF] Ersoy | A geochemical approach to Neogene-Quaternary volcanic activity of western Anatolia: an example of episodic bimodal volcanism within the Selendi Basin, Turkey[END_REF][START_REF] Ersoy | Petrogenesis of the Neogene volcanic units in the NE-SW-trending basins in western Anatolia, Turkey[END_REF][START_REF] Ersoy | Tectono-stratigraphy of the Neogene basins inWestern Turkey: Implications for tectonic evolution of the Aegean Extended Region[END_REF][START_REF] Karaoğlu | Petrogenesis and 40Ar/39Ar geochronology of the volcanic rocks of the Uşak-Güre basin, western Türkiye[END_REF]Purvis et al., 2005;[START_REF] Seyitoğlu | Timing of Cenozoic extensional tectonics in west Turkey[END_REF][START_REF] Seyitoğlu | The evolution from Miocene potassic to Quaternary sodic magmatism in Western Turkey: implications for enrichment processes in the lithospheric mantle[END_REF]). Low-temperature thermochronological studies support this inference, with the majority of the AFT ages ranging between ~30 and ~15 Ma (Gessner et al., 2001a[START_REF] Gessner | What caused the denudation of the Menderes Massif: Review of crustal evolution, lithosphere structure, and dynamic topography in southwest Turkey[END_REF]Ring et al., 2003;[START_REF] Thomson | Thermochronologic evaluation of post-collision extension in the Anatolide Orogen, western Turkey[END_REF]. These data suggest that most of the Menderes Massif was already exhumed above the closure isotherm of the AFT system well before activation of the solid-state shearing of the Salihli granodiorite along the GDF, constrained at ~14 Ma in this study. As a matter of fact, no evidence of Neogene ductile extensional deformation predating the intrusion of the Turgutlu and Salihli plutons has been reported in the literature. Furthermore, younger ZFT and AFT ages (ranging ~2-10 Ma; [START_REF] Buscher | Quantifying rates of detachment faulting and erosion in the central Menderes massif (western Turkey) by thermochronology and cosmogenic 10Be[END_REF] are located only at the footwall of the main extensional detachment systems bounding the central part of the Menderes Massif, the Gediz Detachment to the N and the Büyük Menderes Detachment to the S, respectively (Fig. 1). This evidence suggests that even if extensional tectonics was already active in other areas of the Menderes Massif, at the local scale, the emplacement of the Salihli and

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Turgutlu granodiorites created the rheological conditions for the nucleation and localization of ductile extensional shearing on the GDF.

To sum-up, different crustal domains were exhumed along the Aegean-Menderes transect, with deeper crustal levels and higher degree of partial melting exposed in the Aegean with respect to the Menderes region. The formation of metamorphic core complexes is favored when high geothermal conditions in a thick crustal section promote efficient decoupling between the upper and lower crustal deformation during regional extension (e.g., Bassi, 1995;[START_REF] Brun | Analogue modelling of detachment fault systems and core complexes[END_REF][START_REF] Buck | Modes of continental lithosphere extension[END_REF][START_REF] Gueydan | Strain weakening enables continental plate tectonics[END_REF][START_REF] Whitney | Continental and oceanic core complexes[END_REF]. Crustal melting facilitates decoupling by reducing the effective viscosity and density of the lower crust, determining positive feedbacks between extension and magmatism in core complexes development [START_REF] Whitney | Continental and oceanic core complexes[END_REF]. It is therefore evident that post-orogenic extensional tectonics operated on different geothermal/rheological crustal sections in the Aegean and Menderes realms. In the Aegean, large-scale extension triggered the continuous ascent of the hot, partially molten ductile crust promoting partial melting at different crustal levels, with generation of multiple and distributed extensional detachments. On the other hand, in the Menderes crustal decoupling was not sufficient enough to localize crustal thinning and ductile flow of the lower crust at regional scale.

At local scale, instead, pluton emplacement at shallow crustal conditions caused the rheological weakening of the upper crust, generating the conditions for the localization of ductile extensional shearing and onset of extensional detachment tectonics in the Menderes. This is confirmed by the field evidence attesting the GDF wrapping around the Salihli granodiorite (Fig. 2), which supports the idea that the shape, distribution and activity of extensional detachment was strongly controlled by magma emplacement in the upper crust.

Based on the above, we propose a synthetic tectonic evolutionary model for the activation and development of the GDF in the transition from ductile to brittle deformation conditions (Fig. 9). The model starts in the Early Miocene, when regional crustal thinning promoted the rise of the geothermal gradient and melting of the lower crust (e.g., [START_REF] Whitney | Isothermal decompression, partial melting and exhumation of deep continental crust[END_REF]2013;[START_REF] Vanderhaeghe | Partial melting and flow of orogens[END_REF]. Positive feedbacks between crustal, thinning and melting allowed focused lower crustal flow below the site of active extension, resulting in further

A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 20
decompressional melting and segregation of the Sahlili granodiorite at ca. 17 Ma. Continuous crustal thinning allowed magma emplacement at shallow crustal levels and the transient, local, rise of the regional brittle-ductile transition zone. This process was associated with rheological weakening of the crustal section, allowing ductile shear strain localisation along the exhumed brittle-ductile transition zone and development of GDF at ca. 14 Ma. Solid shearing of the Sahlili granodiorite at the footwall of the GDF was accompanied by formation and subsidence of the Gediz Graben at the hangingwall of the GDF . Continued shearing along the GDF favored focused exhumation at the footwall of the GDF, dominantly assisted by high-angle brittle extensional faulting (Fig. 9).

Concluding remarks

The integrated textural, thermobaric and U-(Th)-Pb titanite geochronological data presented in this study provide evidence that crustal magma emplacement predated onset of the Miocene Gediz-Alaşehir extensional detachment in the Menderes Massif. This evidence suggests that activation of ductile extension was a consequence, rather than the cause, of magma emplacement in the extending crust during the Neogene crustal tinning in the region. This reconstruction also impacts on the amount of exhumation and, more in general, on the amount of extension accommodated by the detachment faults in the Menderes that could be much less than generally thought.

Finally, results of this study reinforce the importance of the rheological perturbation caused by magma intrusion in the crust and, in particular, the role of transient ductile-to-brittle transition and strain softening processes associated with pluton emplacement (e.g. [START_REF] Brun | Analogue modelling of detachment fault systems and core complexes[END_REF][START_REF] Caggianelli | Post-emplacement thermorheological history of a granite intrusion and surrounding rocks: the Monte Capanne pluton, Elba Island, Italy[END_REF][START_REF] Lister | Plutonism and the origin of metamorphic core complexes[END_REF][START_REF] Parsons | Does magmatism influence low-angle normal faults?[END_REF][START_REF] Rabillard | Interactions between plutonism and detachments during metamorphic core complex formation, Serifos Island (Cyclades, Greece)[END_REF] in controlling localization and nucleation of ductile extensional detachment tectonics in extensional provinces. Laurin Technic, Australia). Data were acquired in time-resolved pulse counting mode, with a laser energy of below 2 J cm -2 , a 5 Hz repetition rate and spot size of 43 µm for titanites and 30 µm for GJ-1 reference zircon. Raw data was corrected offline for background signal, common Pb and laser induced, time-dependent element fractionation using an in-house Excel spreadsheet program (Gerdes andZeh, 2006, 2009). Common Pb was estimated iterative from the non radiogenic 207 Pb calculated from the 206 Pb/ 238 U age and the 206 Pb signal assuming a concordant analysis (see [START_REF] Millonig | U-Th-Pb geochronology of metacarbonatites and meta-alkaline rocks in the sourthern Canadian Cordillera: a geodynamic perspective[END_REF]) and a model Pb composition (Stacey and Kramers, 1975).

Subsequently elemental fractionation and mass discrimination were monitored and corrected using GJ-1 zircon as primary reference, while Bearlake titanite BLR and GUF Namaqualand titanite T1 were measured as unknowns to assess precision and accuracy. Repeated analyses (n = 8 and 13) of these secondary reference titanites yield 206 Pb/ 238 U and 207 Pb/ 206 Pb ratios that are precise to about 1% (SD ~ 0.8 %) and 2% (SD ~1.8%), respectively and overlap within 1% with 206 Pb/ 238 U ID-TIMS ages (BLR, 1047.1±0.4 Ma [START_REF] Aleinikoff | Ages and origins of rocks of the Killingworth Dome, south-central Connecticut: implications for the tectonic evolution of southern New England[END_REF]; T1, 998±2 Ma, GUF, unpublished data). Thus there was no need to apply an offset factor to correct for the different sample matrix relative to zircon as primary reference. This was probably accomplish by using the low fluency during ablation and the smaller spot size for GJ-1 zircon.

Electron Microprobe Analysis (EMPA)

A C C E P T E D M A N U S C R I P T calculated at 0.2 GPa with a fixed TiO 2 activity of 0.7 by using the Zr-in-Titanite thermobarometry [START_REF] Hayden | A thermobarometer for sphene (titanite)[END_REF] na: not analyzed; bld: below detection limit a Within run background-corrected mean 207 Pb signal in cps (counts per second). b U and Pb content and Th/U ratio were calculated relative to GJ-1 reference zircon.

(

  Th)-Pb geochronological study in order to constrain timing of the ductile shear strain along the GDF in the transition from magma crystallization to solid-state shearing. Sample selection was based on the structure at the outcrop scale and on meso-and micro-scale textural and Samples are shown in their structural context in Figure2and listed in

  domains do not represent a homogeneous age population. The upper intercepts correspond to a common lead compositions of 207 Pb/ 206 Pb 0.836±0.003 (T14-09) and 0.840±0.003 (T14-06), which are very close or within uncertainty of the 207 Pb/ 206 Pb value predicted by the model of Stacey and Kramers (1975) at 15.5 Ma. Anchoring the 207 Pb/ 206 Pb value data sets to the Stacey and Kramer model (0.8367) results in a only small difference of the lower intercept ages, of 0.10 (T14-9) and 0.47 Ma (T14-6), respectively. Therefore, the data does not indicate any heterogeneity of the common Pb systematics during solid-sate shearing and recrystallisation.

  heterogeneity in the two generations of titanites, together with (i) the spread of 206 Pb*/ 238 U ages (Figs.6 and 7), (ii) the textural and mineralogical evidence documenting fluid assisted recrystallisation and metasomatism[START_REF] Catlos | Geochemistry, geochronology, and cathodoluminescence imagery of the Salihli and Turgutlu granites (central Menderes Massif, western Turkey): implications for Aegean tectonics[END_REF] this study), and (iii) the REE redistribution in Ttn that spatially correlates with the chemical zoning and the U-Pb-Th systematics in Ttn (see also[START_REF] Bonamici | Combined oxygen-isotope and U-Pb zoning studies of titanite: New criteria for age preservation[END_REF] (Figs.5 and 7) collectively suggest that the Ttn from the predominantly open-system dates and radiogenic Pb diffusion during fluid-assisted syn-tectonic allochemical re-equilibration/recrystallization of Ttn.

  generations, and assuming (i) the final crystallization/emplacement temperature of the Salihli granodiorite at ~630-700°C (Zr-in-Ttn 1 thermometry) at ~17 Ma (sample T14-09), (ii) the thermal environment associated with the solid-state syn-metamorphic overprint during ductile shearing as occurred under amphibolite-grade conditions (T window 530-580 °C; Amp-Pl thermobarometry) and completed at ~14 Ma (sample T14-06), and (iii) taking into account published radiometric and thermochronological age data[START_REF] Buscher | Quantifying rates of detachment faulting and erosion in the central Menderes massif (western Turkey) by thermochronology and cosmogenic 10Be[END_REF] Catlos et al., A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT

(

  [START_REF] Öner | Geology and geochemistry of the synextensional Salihli granitoid in the Menderes core complex, western Anatolia, Turkey[END_REF] Purvis and Robertson, 2007) Comparison with the Aegean region and a model for the development of the GDFIn the Aegean region, the Neogene post-orogenic tectonic setting is dominated by the activation of multiple ductile-to-brittle extensional detachment systems[START_REF] Grasemann | Localization of deformation triggered by chemomechanical feedback processes[END_REF] Jolivet et al., 2010 and references therein) associated with the polyphase syn-tectonic, middleA C C E P T E DM A N U S C R I P T

  Titanites were analysed in in situ in thin section by laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) at the Goethe University of Frankfurt (GUF), using a slightly modified method, as previously described inGerdes and Zeh (2006, 2009) and[START_REF] Millonig | U-Th-Pb geochronology of metacarbonatites and meta-alkaline rocks in the sourthern Canadian Cordillera: a geodynamic perspective[END_REF]. A ThermoScientific Element 2 sector field ICP-MS was coupled to a Resolution 193 nm ArF Excimer laser (CompexPro 102, Coherent) equipped with two-volume ablation cell (S-155;

Figure 1 -

 1 Figure 1 -Synthetic tectonic map of southwestern Turkey showing the main tectonic structures of

Figure 2 -

 2 Figure 2 -(a) Equal area stereoplots (Schmidt net, lower hemisphere projections) showing the

Figure 3 -

 3 Figure 3 -Proto mylonite textures. (a) Meso-scale appearance, with secondary sub-horzontal

Figure 4 -

 4 Figure 4 -Mylonite textures as observed in sections cut parallel to the stretching direction and

Figure 5 -

 5 Figure 5 -(a) Euhedral titanite (Ttn 1 ) grain in a recrystallised quartz-feldspar matrix. The circles

Figure 6 -

 6 Figure 6 -Tera-Wasserburg Concordia diagrams of not common Pb corrected data from titanites of the two samples. Probability density distributions of the common Pb corrected 206 Pb/ 238 U ages

Figure 7 -

 7 Figure 7 -Left: Plot of the cumulative common Pb corrected 206 Pb/ 238 U ages vs. the Th/U data for the studied titanite grains. Right: BSE image showing comparison of 206 Pb/ 238 U ages and

Figure 8 -Figure 9 -

 89 Figure 8 -Temperature-time (T-t) evolution of the Salihli granodiorite (footwall of the Gediz detachment fault). Time and temperature constrains are from: (1) Hetzel et al., 1995a ( 40 Ar/ 39 Ar

Table

  1, where their location, fabrics, and constituent mineralogy are detailed. Electron microprobe analyses (EMPA) were used to define compositions of the constituent mineral assemblages.

Table 2a

 2a

-d for representative mineral compositions) consists of Kfs (X Or 90-94%, X An < 2%) + Pl 1 + Qz + A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 9 Amp 1 + Bt 1 and Ttn 1 ,

Table 2d

 2d

	; Figs. 5e-f). The Ttn 1 grains
	systematically show elevated contents of Y 2 O 3 (1.02-2.45 wt%) and ΣREE (1.05-2.30 wt%), low
	(Ce/Nd) N (0.30-0.66, REE-Chondrite normalization after Sun and McDonough, 1989) and high
	(Y/Nb) N (0.32-1.59, Primitive Mantle normalization after McDonough et al., 1991), in
	conjunction with higher values of Th/U (0.70-1.23; see below). Ttn 2 composition presents Y 2 O 3
	(0.0-0.76 wt%) and ΣREE (< 0.70wt%), with low (Y/Nb) N (0.0-0.44) values, and lower Th/U
	(0.05-0.69; see below). The Zr content is high (up to 0.04 wt.% ZrO 2 ) in Ttn 1 , whereas in Ttn 2 ,
	either as overgrowth or matrix grains, it is below detection limit of the microprobe. Finally, the
	Ttn 1 generation usually shows higher contents of Al 2 O 3 and Fe 2 O 3 compared to Ttn 2 , but this
	pattern is not systematically observed. This is at odds with the observation of Wintsch et al.
	(2005), who measured systematically lower Al contents in the igneous cores compared to
	metamorphic rims.

Table Captions Table 1 -

 Captions1 Sample location, fabrics and constituent mineralogy

	Table 2a-d -Mineral chemistry
	Table 3 -U-(Th)-Pb LA-ICPMS data on titanite

Table 1 -Location of selected samples with constituent mineralogy and analytical technique adopted

 1

							Ttn U-(Th)-Pb
	Sample Latitude	Longitude	Structural fabric	Mineral assemblage	EMPA	geochronology
		N 38° 25'	E 28° 12'	S-L tectonite	Qz-Fsp-Pl-Bt-Amp + Ilm + Ttn + All + Ap +
	T14-6	13.7"	27.4"	(mylonite)	Zrc	X	X
		N 38° 24'	E 28° 13'	S-L tectonite
	T14-8	00.6"	25.9"	(mylonite)	Qz-Fsp-Pl-Bt-Amp + Ilm + Ttn + Ap + Zrc	X
		N 38° 24'	E 28° 13'		Qz-Fsp-Pl-Bt-Amp + Ilm + Ttn + All + Ap +
	T14-9	10.0"	37.6"	protomylonite	Zrc	X	X
		N 38°	E 28° 14'
	T14-10	24'22.7"	01.6"	protomylonite	Qz-Fsp-Pl-Bt-Amp + Ilm + Ap + Zrc	X

Table -

 - Representative EMPA and chemical formulas of feldspar

			ACCEPTED MANUSCRIPT
	Sample	T14-9 T14-9 T14-6	T14-6	T14-6	T14-6	T14-9 T14-6	T14-6	T14-6
	Mineral				Plagioclase				K-feldspar
	Pl1 -Core #32 50.95 51.17 55.39 #5 #6 31.33 30.70 28.63 0.05 0.04 0.04 13.59 13.54 10.50 3.80 3.90 5.44 0.10 0.15 0.10 0.02 0.02 bdl 99.83 99.51 100.09 100.17 #39 57.44 27.33 0.04 8.88 6.39 0.09 bdl Formula (8 Oxygens) Point No. SiO 2 Al 2 O 3 FeOt CaO Na 2 O K 2 O BaO Total	Pl1 -Rim #91 59.74 #37 60.47 25.77 25.62 0.12 0.01 7.05 6.73 7.27 7.48 0.11 0.08 0.01 0.02 100.07 100.42 M A N U S C R I P T Pl2 -overgrowth #3 #44 61.65 62.42 24.14 24.17 0.00 0.20 5.23 5.44 8.48 8.43 0.22 0.14 bdl bdl 99.72 100.81	#30 64.23 18.52 0.00 0.00 0.61 16.34 0.42 100.13 100.24 #87 65.06 18.43 0.01 0.03 0.96 15.30 0.47
	Si (apfu) Al Ba Ca Na K An Ab Or	2.32 1.68 0.00 0.66 0.34 0.01 0.66 0.33 0.01	2.34 1.65 0.00 0.66 0.35 0.01 0.65 0.34 0.01 A C C E P T E D 2.49 2.57 2.66 1.52 1.44 1.35 0.00 0.00 0.00 0.51 0.43 0.34 0.47 0.55 0.63 0.01 0.01 0.01 0.51 0.43 0.35 0.48 0.56 0.65 0.01 0.01 0.01	2.68 1.34 0.00 0.32 0.64 0.00 0.33 0.66 0.00	2.74 1.26 0.00 0.25 0.73 0.01 0.25 0.74 0.01	2.74 1.25 0.00 0.26 0.72 0.01 0.26 0.73 0.01	2.98 1.01 0.01 0.00 0.05 0.97 0.01 0.09 0.90	3.00 1.00 0.01 0.00 0.09 0.90 0.99 0.09 0.90
						51

Table 2b -

 2b Representative EMPA and chemical formulas of biotite and epidote

					ACCEPTED MANUSCRIPT
	Sample	T14-9	T14-6	T14-6	T14-6			T14-9	T14-6
	Mineral			Biotite				Epidote
			Bt1		Bt2
	Point No.	#10	#76	#48	#58			#28	#51
	SiO 2 TiO 2 Al 2 O 3 FeOt MnO MgO CaO Na 2 O K 2 O BaO	36.10 2.69 15.91 20.81 0.39 9.08 0.03 0.14 9.59 0.39	36.76 3.02 16.16 19.98 0.34 9.40 0.01 0.09 9.80 0.22	37.44 0.29 18.50 17.63 0.32 10.35 0.01 0.04 9.58 bdl	36.09 1.06 18.41 17.99 0.39 9.33 0.03 0.04 9.82 0.03	SiO 2 TiO 2 Al 2 O 3 FeOt MnO MgO CaO Na 2 O K 2 O BaO M A N U S C R I P T 39.44 38.73 0.11 0.13 27.19 27.84 6.94 6.26 0.17 0.22 0.03 bdl 23.48 23.06 0.03 0.02 0.07 bdl 0.02 0.01
	Total Formula (11 Oxygens) 95.12 Si (apfu) 2.79 Al_T 1.21 Ti 0.16 Al_O 0.25 Fe2 1.35 Mn 0.03 Mg 1.05	95.77 2.81 1.19 0.17 0.26 1.28 0.02 1.07	94.16 2.85 1.15 0.02 0.51 1.12 0.02 1.17 A C C E P T E D 93.18 2.80 1.20 0.06 0.48 1.17 0.03 1.08	Total Formula (12.5 Oxygens) 97.50 96.27 Si (apfu) 3.06 3.03 Ti 0.01 0.01 Al 2.48 2.57 Fe3 0.45 0.41 Mg 0.00 0.00 Mn --Ca 1.95 1.93
	Ca	-	-	-	-		Na	-	-
	Na	0.02	0.01	0.01	0.01		K	-	-
	K	0.95	0.95	0.93	0.97		Ba	-	-
	Ba	0.01	0.01	-	-
	XAl	0.12	0.13	0.25	0.24		XFe	0.15	0.14
							52

Table 2c .

 2c Representative EMPA and chemical formulas of amphiboles with results of the Hbl-Pl thermobarometry Amphibole formula and P-T models recalculated with "Plagioclase-Hornblende Thermobarometry" Excel spreadsheet in[START_REF] Anderson | Thermometers and thermobarometers in granitic systems[END_REF]. -Representative EMPA and chemical formulas of Titanite with results of the Zr-in Ttn thermobarometry

	Sample Point No. SiO 2 TiO 2 Al 2 O 3 FeOt MnO MgO CaO Na 2 O K 2 O Total Formula: 23(O) (*) Al(total) Si (T) Al iv (T) Fe 2+ Ca M4 site Fe Ca Na A site Ca Na K Sum A OH site OH Sum cations IMA-04 P (Al-in-Hbl) (kbar) T (Ti-in-Hbl) (°C) P (Hbl-Pl) (kbar) T (Hbl-Pl) (°C) Point No. SiO 2 (wt%) Al 2 O 3 P 2 O 5 La 2 O 3 Ce 2 O 3 Pr Yb 2 O 3 ƩREE ZrO 2 F Total Formula (25 O) Si P sum Nd Sm Gd Dy Er Yb sum (*) Table2d Sample [XAn 35%] [XAn 35%] T14-6 #3 29.10 2.32 0.06 bdl 0.28 na -1.06 0.041 0.10 95.73 1.006 0.002 1.011 0.006 0.004 ----0.994 TiO 2 33.88 Fe 2 O 3 0.64 MnO 0.02 Al 0.094 F 0.011 CaO 25.47 Fe 0.017 (Ce/Nd) N 0.43 Nb 2 O 5 1.09 Y 2 O 3 1.96 Ti 0.881 Nb 0.017 0.32 (Y/Nb) N T(Zr-in-Ttn)(°C) (*) 691 (*)	T14-6 T14-6 T14-9 T14-9 Amph1 #25 #64 #67 #68 49.71 48.50 49.44 49.40 0.65 0.68 0.62 0.62 5.47 5.90 5.82 5.34 16.48 16.09 15.76 15.42 0.67 0.66 0.62 0.62 11.53 11.34 11.24 11.86 11.81 11.16 11.29 11.29 0.63 0.76 0.61 0.64 0.54 0.54 0.50 0.50 97.49 95.63 95.91 95.71 0.951 1.044 1.026 0.942 7.34 7.29 7.39 7.39 0.66 0.71 0.61 0.61 1.83 1.76 1.85 1.74 0.00 0.00 0.00 0.00 0.01 0.05 0.04 0.05 1.87 1.80 1.81 1.81 0.12 0.15 0.15 0.14 0.00 0.00 0.00 0.00 0.06 0.07 0.03 0.05 0.10 0.10 0.10 0.10 0.16 0.17 0.12 0.14 2.00 2.00 2.00 2.00 15.16 15.17 15.12 15.14 Mg-hornblende 1.52 1.96 1.87 1.47 631 638 629 629 1.66 2.13 1.97 1.60 623 632 590 616 T14-6 T14-6 T14-6 T14-6 Magmatic Cores [XAn 25%] [XAn 25%] T14-6 #5 #6 #7 #11 #15 29.90 29.90 29.38 29.96 29.33 2.53 2.29 2.20 2.31 2.00 0.03 0.04 0.05 0.04 0.07 bdl bdl bdl bdl bdl 0.25 0.25 0.29 0.16 0.29 0.13 0.10 0.14 0.12 na -----1.92 2.13 2.29 1.06 0.90 0.011 0.023 0.024 0.008 0.019 0.17 0.22 0.14 0.29 0.22 98.64 99.41 97.97 98.60 96.89 1.008 1.003 1.002 1.006 1.001 0.001 0.001 0.001 0.001 0.002 1.003 1.006 1.002 1.013 1.015 0.005 0.005 0.006 0.002 0.005 0.003 0.003 0.003 -0.002 0.004 0.006 0.005 0.003 -0.004 0.004 0.005 0.003 -0.002 0.002 0.002 0.001 -0.001 0.001 0.001 0.001 -1.017 1.017 1.010 1.013 1.008 34.77 35.28 34.45 35.44 35.49 0.64 0.74 0.61 0.81 0.61 0.04 0.04 0.03 0.08 0.06 0.101 0.091 0.088 0.092 0.080 0.018 0.023 0.015 0.031 0.024 26.65 26.74 25.79 27.13 26.53 0.016 0.019 0.016 0.021 0.016 0.49 0.47 0.43 0.64 0.54 0.24 0.35 0.85 0.29 0.35 1.73 1.66 2.15 1.18 1.32 0.882 0.890 0.884 0.895 0.911 0.004 0.005 0.013 0.004 0.006 1.25 0.84 0.45 0.71 0.66 628 663 665 615 653	T14-6 #40 51.18 0.19 4.26 15.71 0.59 12.38 11.96 0.45 0.33 97.05 0.739 7.54 0.46 1.78 0.00 0.03 1.89 0.09 0.00 0.04 0.06 0.10 2.00 15.10 0.51 570.61 n.v. 553 T14-6 #31 29.88 2.15 0.06 bdl 0.36 0.07 -2.24 0.030 0.22 98.77 1.007 0.002 1.002 0.008 0.004 0.004 0.004 0.002 0.001 1.011 35.25 0.48 0.03 0.086 0.024 26.54 0.012 0.41 0.56 1.31 0.894 0.009 0.41 675	T14-6 #46 51.62 0.25 4.48 15.60 0.62 12.26 12.07 0.53 0.34 97.77 0.772 7.54 0.46 1.80 0.01 0.00 1.88 0.12 0.00 0.03 0.06 0.10 2.00 15.10 Actinolite T14-6 Amph2 #69 50.84 0.23 4.34 14.95 0.58 12.23 11.66 0.38 0.35 95.56 0.764 7.59 0.41 1.80 0.00 0.04 1.86 0.10 0.00 0.01 0.07 0.08 2.00 15.08 0.67 0.63 578.34 575.68 n.v. n.v. 556 531 T14-9 T14-9 T14-6 #66 #74 #3 29.76 29.8 4 30.9 2 1.94 1.85 2.30 1.39 1.64 1.33 1.69 1.46 1.92 2.01 T14-6 #89 50.95 0.18 4.62 15.15 0.64 12.17 11.98 0.45 0.36 96.50 0.805 7.54 0.46 1.79 0.00 0.00 1.90 0.10 0.00 0.03 0.07 0.10 2.00 15.10 0.82 569.51 n.v. 539 T14-6 T14-6 T14-6 T14-6 T14-6 T14-6 T14-6 Metamorphic Rim (overgrowth), Matrix #9 #14 #16 #26 #28 #48 #55 30.1 4 30.4 3 29.7 5 30.8 2 30.1 2 30.5 2 30.6 1 0.06 0.04 0.04 0.03 0.03 0.04 0.02 0.03 0.04 0.03 35.9 36.1 36.8 36.3 36.8 37.1 37.0 36.8 36.7 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 0.29 0.19 bdl 0.06 0.11 0.14 bdl 0.11 0.08 0.06 0.11 0.14 bdl 0.14 0.09 na bdl na bdl bdl ----------1.38 1.23 0.00 0.00 0.70 0.42 0.14 0.00 0.11 0.08 0.06 bdl 0.01 5 bdl bdl bdl bdl bdl bdl bdl bdl 0.22 0.20 0.45 0.27 0.20 0.24 0.44 0.33 0.33 0.34 98.63 98.5 7 98.7 4 98.2 2 98.2 6 97.3 5 99.0 8 98.0 3 99.0 0 98.9 2 1.000 1.00 3 1.02 6 1.01 0 1.01 6 1.00 4 1.02 1 1.00 9 1.01 1 1.01 4 0.002 0.00 1 0.00 1 0.00 1 0.00 1 0.00 1 0.00 1 0.00 1 0.00 1 0.00 1 1.008 4 2 8 7 5 3 1 7 9 0.96 0.99 0.97 0.98 1.01 1.00 1.00 1.00 1.00 0.004 3 ------------------0.004 0.00 3 -0.00 2 ------0.002 0.00 3 -0.00 2 0.00 2 -----0.001 0.00 2 -0.00 2 ------0.001 0.00 2 -0.00 1 0.00 1 -----1.012 1.01 5 0.99 8 1.01 3 1.00 8 1.02 0 1.01 2 1.00 8 1.01 7 1.01 4 35.91 1 8 5 7 6 1 7 3 8 0.47 0.57 0.60 0.33 0.51 0.35 0.40 0.54 0.37 0.43 0.06 0.08 0.077 0.07 3 0.09 0 0.09 2 0.06 5 0.05 3 0.06 6 0.05 8 0.07 5 0.07 0.02 0.04 0.02 0.02 0.02 0.04 0.03 0.03 0.03 9 0.01 0.01 0.01 0.01 0.00 0.01 0.01 0.00 0.023 2 7 9 1 6 6 5 4 5 0.01 0.08 0.06 0.06 0.08 0.05 0.07 0.06 0.07 26.87 26.9 0 27.9 3 28.0 5 27.4 7 27.9 5 28.4 1 27.9 0 28.4 3 0.012 5 5 6 3 9 0 4 9 1 28.3 0.90 0.90 0.89 0.91 0.93 0.92 0.93 0.91 0.91 0.66 0.63 --------9 0.66 0.43 0.20 0.31 0.37 0.37 0.13 0.29 0.25 0.13 1.31 1.50 0.04 0.08 0.76 0.22 0.02 0.11 0.16 0.07 0.908 9 3 5 3 6 5 5 8 7 0.010 0.00 7 0.00 3 0.00 4 0.00 6 0.00 6 0.00 2 0.00 4 0.00 4 0.35 0.62 0.03 0.04 0.37 0.11 0.02 0.07 0.11 0.09 0.00 -642 --------2 1.00 1.01 1.00 0.99 1.00 1.00 1.01 1.00 1.00
	Pr 2 O 3 Ca M1,2,3 sites Al vi Ti Nd 2 O 3 Mn Sm 2 O 3	bdl 0.943 0.49 0.001 0.29	bdl 0.962 0.29 0.07 0.38 0.001 0.23	bdl 0.961 0.33 0.08 0.41 0.001 0.26	bdl 0.942 0.42 0.07 0.51 0.001 0.29	bdl 0.976 0.33 0.07 0.19 0.002 bdl	bdl 0.970 0.41 0.002 0.20	bdl 0.959 0.28 0.02 0.66 0.001 0.30	bdl 0.968 0.31 0.03 0.33 0.002 bdl	bdl 9 0.23 0.35 0.03 0.00 2 bdl 0.02	bdl 2 bdl 0.00 2 bdl 0.00	bdl 6 0.34 bdl 0.00 2 0.02 bdl 0.02	bdl 3 bdl 0.00 2 bdl 0.01	bdl 1 bdl 0.00 2 bdl 0.00	bdl 8 bdl 0.00 1 bdl 0.00	bdl 2 bdl 0.00 2 bdl 0.00	bdl 9 bdl 0.00 2 bdl 0.00	bdl 8 0.00 bdl 2 bdl 0.00
	Fe 3+ Gd 2 O 3 Y	na 0.036	0.19 0.36 0.031	0.21 0.54 0.030	0.08 0.40 0.039	0.14 0.23 0.021	na 0.024	0.13 0.36 0.024	0.11 0.37 0.023	0.03 0.26 7	bdl 1	0.09 0.19 bdl 2 4	na 4	bdl 0	na 2	bdl 3	bdl 1
	Mg Mn Dy 2 O 3 La Er 2 O 3 Ce	na -na 0.004	2.54 0.08 0.36 -0.20 0.003	2.54 0.08 0.39 -0.17 0.003	2.50 0.08 0.45 -0.23 0.004	2.64 0.08 0.25 -0.11 0.002	na -na 0.004	2.72 0.07 0.36 -0.14 0.004	2.67 0.08 0.16 -0.12 0.004	2.72 0.07 0.24 -0.16 0.00 2	bdl -bdl -	2.68 0.08 0.17 0.22 na ---0.14 bdl na 0.00 0.00 0.00 2 1 2	bdl -bdl -	na -na 0.00 1	bdl -bdl 0.00 1	-bdl 0.00 bdl 1

Table 3 -U-Th-Pb data on Titanite

 3 30 and 43 µm, respectively; depth of crater ~15µm. 206 Pb/ 238 U error is the quadratic additions of the within run precision (2 SE) and the external reproducibility (2 SD) of the reference zircon. 207 Pb/ 206 Pb error propagation ( 207 Pb signal dependent) following Gerdes & Zeh (2009). 207 Pb/ 235 U error is the quadratic addition of the 207 Pb/ 206 Pb and 206 Pb/ 238 U uncertainty. uncertainty.

	Spot	Sample Grain 207 Pb a	U b	Pb b	Th b	206 Pb c	±2σ 207 Pb c	±2σ 207 Pb c	±2σ rho d 206 Pb	±2σ 206 Pb* ±2σ
				(cps)	(ppm) (ppm) U	238 U	(%) 235 U	(%) 206 Pb	(%)	238 U	(Ma) 238 U	(Ma)
	A06	T14-09	tit1	19401	209	15	0.95	0.02231 4.2	2.342	4.4	0.7616	1.3	0.95 142	6	17.6	1.3
	A07	T14-09	tit1	24420	168	13	0.67	0.02533 6.7	2.702	6.8	0.7738	1.3	0.98 161	11	14.2	1.3
	A08	T14-09	tit1	31233	134	47	0.71	0.1617	5.0	18.5	5.8	0.8300	2.9	0.87 966	45	14.5	0.9
	A09	T14-09	tit1	7011	157	5	0.75	0.01086 4.4	1.021	4.8	0.682	2.1	0.90 70	3	14.0	0.9
	A10	T14-09	tit1	11744	155	10	0.76	0.0209	6.0	2.117	6.3	0.7349	2	0.95 133	8	16.1	1.3
	A11	T14-09	tit1	18499	226	15	0.60	0.02288 4.2	2.35	4.5	0.7450	1.7	0.93 146	6	16.6	1.3
	A12	T14-09	tit1	8643	151	7	0.84	0.01399 5.2	1.335	5.6	0.6924	1.9	0.94 90	5	18.4	1.0
	A13	T14-09	tit1	37458	243	29	0.52	0.03537 9.6	3.767	9.6	0.7727	1.1	0.99 224	21	16.5	1.1
	A14	T14-09	tit1	17878	163	13	0.75	0.02211 5.2	2.316	5.5	0.7598	1.7	0.95 141	7	17.3	1.2
	A15	T14-09	tit1	9433	191	8	0.67	0.01468 4.1	1.427	4.5	0.7052	1.9	0.91 94	4	15.6	1.2
	A16	T14-09	tit1	21676	145	20	0.86	0.05797 5.3	6.332	6.4	0.7925	3.6	0.83 363	19	16.7	1.3
	A38	T14-09	tit3	13243	243	9	0.66	0.01151 4.9	1.043	5.2	0.6578	1.8	0.94 74	4	18.0	1.0
	A39	T14-09	tit3	11469	286	10	0.46	0.01265 3.9	1.173	4.2	0.6725	1.7	0.91 81	3	17.8	1.0
	A40	T14-09	tit3	43576	315	33	0.47	0.02963 12.2 3.134	12.2 0.7673	1.2	0.99 188	23	16.1	1.2
	A41	T14-09	tit3	32183	288	23	0.49	0.02293 12.6 2.382	12.7 0.7536	1.8	0.99 146	18	15.5	1.0
	A42	T14-09	tit3	22320	156	16	0.86	0.04006 14.8 4.273	14.9 0.7739	1.7	0.99 253	37	18.1	1.2
	A44	T14-09	tit3	19655	171	16	0.69	0.03145 4.9	3.303	5.1	0.7620	1.5	0.96 200	10	16.1	1.2
	A45	T14-09	tit4	56068	184	39	0.39	0.05819 6.3	6.456	6.4	0.8049	0.91 0.99 365	23	16.8	1.3
	A46	T14-09	tit4	82888	68	53	0.49	0.3058	3.8	35.37	3.9	0.8390	0.97 0.97 1720	57	18.1	1.7
	A48	T14-09	tit4	20416	347	14	0.74	0.01213 5.4	1.157	5.7	0.6920	2	0.94 78	4	16.5	0.9
	A49	T14-09	tit4	17464	281	14	0.58	0.01636 6.1	1.607	6.5	0.7127	2.2	0.94 105	6	16.5	0.9
	A50	T14-09	tit5	27502	242	21	0.57	0.02859 10.3 2.99	10.5 0.7585	1.5	0.99 182	19	17.5	1.6
	A51	T14-09	tit5	12537	277	9	0.54	0.0111	5.1	1.013	5.4	0.662	1.6	0.96 71	4	17.3	0.9
	A52	T14-09	tit5	61613	309	41	0.56	0.03465 11.0 3.737	11.0 0.7825	0.84 1.00 220	24	16.7	1.4
	A53	T14-09	tit5	14647	311	10	0.54	0.00972 3.9	0.8611 4.3	0.6430	1.7	0.92 62	2	13.5	0.8
	A54	T14-09	tit6	92575	309	33	0.47	0.00796 8.3	0.6624 8.4	0.6038	0.92 0.99 51	4	14.4	1.0
	A82	T14-09	tit9	26234	75	17	0.66	0.05301 5.8	5.907	5.9	0.8085	1.2	0.98 333	19	14.3	3.6
	A83	T14-09	tit9	19282	124	14	0.87	0.03476 6.0	3.788	6.2	0.7906	1.5	0.97 220	13	15.9	1.2

c corrected for background, within-run Pb/U fractionation (in case of 206 Pb/ 238 U) and subsequently normalised to GJ-1 (ID-TIMS value/measured value) 207 Pb/ 235 U calculated using 207 Pb/ 206 Pb/( 238 U/ 206 Pb*1/137.88) d rho is the 206 Pb/ 238 U/ 207 Pb/ 235 U error correlation coefficient. * corrected for common Pb using Stacy and Kramers (1975) model Pb composition e Accuracy and reproducibilty was checked by repeated analyses (n = 8) of reference zircon BB-16 and Plesovice, Manangotry monazite and Bear lake titanite; data given as mean with

Acknowledgements

This paper benefitted of constructive reviews and criticism from an anonymous reviewer and B. Cenki-Tok. Field assistance by Üha Özden, Oğuz H. Göğüş, Alper Yangöz, Semih Can Ülgen and Nazik Öğretmen is kindly acknowledged.