domain: spi chim

text:
Rabeb Lachhab
email: lachhab_rabeb@hotmail.com

Mohamed Ali Rekik

Thierry Baudin

Anne Laure Helbert

François Brisset

Mohamed Khitouni

Microstructure and mechanical properties of Fe-48(wt.%)Ni alloy processed by equal channel angular pressing

Keywords: Microstructure, FeNi alloys, ECAP, EBSD, mechanical properties

The microstructure and mechanical properties of a Fe-48wt%Ni alloy in form of stacked sheets and bulk billet after severe plastic deformation using equal channel angular pressing (ECAP) were investigated. Samples were passed through a die with an inner angle of Φ = 90° and outer arc of curvature of ψ = 17° at room temperature. X-ray diffraction and Electron Backscatter Diffraction were used to evaluate phase transformation and microstructure before and after ECAP process. Heterogeneous structure was identified by the formation of shear bands during severe plastic deformation. The crystallite size decreased down to 30 nm. In order to characterize the mechanical properties, tensile tests were carried out. Results of mechanical tests showed a significant loss of ductility after ECAP compared to the initial material with an increase in tensile strength from 459 MPa to a maximum value of 676 MPa. This increase is accompanied by enhanced dislocation density (2.10 15 m -2 ) and was related to grain refinement. Moreover, the alloy has shown a decrease in elongation to failure to values of approximately 22%. The fracture surface morphology shows the formation of a specific dimple relief.

Introduction

Severe plastic deformation (SPD) has been studied extensively due to its potential to produce full density fine-grained structures with attractive physical and mechanical properties [START_REF] Segal | Plastic working of metals by simple shear[END_REF][START_REF] Valiev | Plastic deformation of alloys with submicron-grained structure[END_REF][START_REF] Valiev | Structure and properties of ultrafinegrained materials produced by severe plastic deformation[END_REF][START_REF] Valiev | Bulk nanostructured materials from severe plastic deformation[END_REF][START_REF] Valiev | Principles of equal-channel angular pressing as a processing tool for grain refinement[END_REF]. Among the techniques for preparing such structures, High Pressure Torsion (HPT) [START_REF] Valiev | The innovation potential of bulk nanostructured materials[END_REF][START_REF] Heczel | Defect structure and hardness in nanocrystalline CoCrFeMnNi High-Entropy Alloy processed by High-Pressure Torsion[END_REF][START_REF] Pustov | Face-centered cubic phase stability and martensitic transformation under deformation in Fe-Ni and Fe-Mn alloys nanostructured by mechanical alloying and highpressure torsion[END_REF], Accumulative Roll Bonding (ARB) [START_REF] Saito | Ultra-fine grained bulk aluminum produced by accumulative roll-bonding (ARB) process[END_REF][START_REF] Tohidi | Nanograined Ti-Nb microalloy steel achieved by Accumulative Roll Bonding (ARB) process[END_REF][START_REF] Haj Larbi | Neutron diffraction versus EBSD analysis of the texture in Fe-36%Ni alloy after accumulative roll bonding[END_REF][START_REF] Tirsatine | Texture and microstructure evolution of Fe-Ni alloy after Accumulative Roll Bonding[END_REF][START_REF] Azzeddine | Texture evolution of an Fe-Ni alloy sheet produced by cross accumulative roll bonding[END_REF] and Equal Channel Angular Pressing (ECAP) are found [START_REF] Valiev | Bulk nanostructured materials from severe plastic deformation[END_REF][START_REF] Valiev | Principles of equal-channel angular pressing as a processing tool for grain refinement[END_REF][START_REF] Khelfa | Microstructure and strengthening mechanisms in an Al-Mg-Si alloy processed by equal channel angular pressing (ECAP)[END_REF][START_REF] Lugo | Grain refinement of pure copper by ECAP[END_REF]. ECAP is considered as a well-developed method to prepare materials with an ultra-fine grain (UFG) microstructure. In this process, a sample is pressed through a die having two channels of equal cross-section intersecting at an inner angle Φ and at the outer arc of curvature Ψ. During the ECAP process, although the sample undergoes severe shear deformation, it retains the same cross-sectional geometry. Therefore, the same piece can be pressed repetitively through the die channel introducing additional strain. There is much current interest in producing metals and alloys with very small grain sizes, because a reduction in grain size leads to significant material strength and toughness improvement at room temperature. The average grain size reduction during ECAP depends on several parameters including the processing route and the number of passes. So far, the main conclusions of previous investigations on the mechanical properties of metals and alloys processed by ECAP are hardening caused by grain refinement, sometimes dramatic, with a Hall-Petch-type relationship [START_REF] Valiev | Bulk nanostructured materials from severe plastic deformation[END_REF][START_REF] Valiev | Principles of equal-channel angular pressing as a processing tool for grain refinement[END_REF][START_REF] Khelfa | Microstructure and strengthening mechanisms in an Al-Mg-Si alloy processed by equal channel angular pressing (ECAP)[END_REF][START_REF] Lugo | Grain refinement of pure copper by ECAP[END_REF]. Due to their low grain size, the processed samples contain, therefore, large number of grain boundaries and high amount of lattice defects, such as vacancies, dislocations, and staking faults [START_REF] Dalla | Microstructures and properties of copper processed by equal channel angular extrusion for 1-16 passes[END_REF][START_REF] Ungar | The effect of dislocation contrast on X-ray line broadening:A new approach to line profile analysis[END_REF].

Soft magnetic nickel-iron alloys containing about 30 to 80% Ni are the most ductile and most flexible alloys currently in use [START_REF]ASM Specialty Handbook: Nickel, Cobalt, and Their Alloys[END_REF]. Their exceptional ductility permits production of thin foil or wire shapes. Furthermore, many elements can enter into solid solution, permitting tailoring of their magnetic and physical properties such as a low thermal expansion coefficient and an absence of brittleness at low temperatures, conservation properties after thermal cycling, paramagnetic to ferromagnetic transition after polymorphism, strain hardening, etc. [START_REF]ASM Specialty Handbook: Nickel, Cobalt, and Their Alloys[END_REF]. The nickel-iron alloys are extensively employed in various applications including electronic devices and electromagnetic shielding of computers and communication equipment.

Recently, many researchers have focused on the effect of SPD in Fe-Ni alloys. As an example, Pustov et al. [START_REF] Pustov | Face-centered cubic phase stability and martensitic transformation under deformation in Fe-Ni and Fe-Mn alloys nanostructured by mechanical alloying and highpressure torsion[END_REF] revealed that the temperature of →2 martensitic transformation of Fe100-xNix(x=14-28) alloys produced by mechanical alloying (MA) and HPT is reduced by 300-350K compared with conventionally prepared alloys. They attributed this decrease of temperature to small crystallite grain size (d=60-90 nm). Due to its exceptional properties, Fe-36%Ni alloy (Invar) has attracted great and unceasing attention and many studies were carried out to evaluate the texture and microstructure changes after SPD as ARB [START_REF] Haj Larbi | Neutron diffraction versus EBSD analysis of the texture in Fe-36%Ni alloy after accumulative roll bonding[END_REF][START_REF] Tirsatine | Texture and microstructure evolution of Fe-Ni alloy after Accumulative Roll Bonding[END_REF] and Cross Accumulative Roll Bonding CARB [START_REF] Azzeddine | Texture evolution of an Fe-Ni alloy sheet produced by cross accumulative roll bonding[END_REF]. In fact, after 10 ARB cycles, elongated ultrafine grains microstructure was obtained in Fe36%Ni and according to the authors [START_REF] Tirsatine | Texture and microstructure evolution of Fe-Ni alloy after Accumulative Roll Bonding[END_REF], six ARB cycles were enough to homogenize the UFG microstructures and the hardness of the materials without lubrication. Compared with ARB processing [START_REF] Tirsatine | Texture and microstructure evolution of Fe-Ni alloy after Accumulative Roll Bonding[END_REF], Azzedine et al [START_REF] Azzeddine | Texture evolution of an Fe-Ni alloy sheet produced by cross accumulative roll bonding[END_REF] have noted an improvement of Vickers microhardness up to 10% in samples processed by CARB.

As far as we know, few studies have focused on the evaluation of Fe-48%Ni alloy behavior after SPD [START_REF] Betanda | Influence of sulfur on the recrystallization and {100}<001> Cube texture formation in Fe48% Ni alloys tapes[END_REF][START_REF] Betanda | Measurement of stored energy in Fe-48%Ni alloys strongly cold-rolled using three approaches: Neutron diffraction, Dillamore and KAM approaches[END_REF][START_REF] Boudekhani-Abbas | Texture, microstructure and mechanical properties evolution in Fe-x (x=36 and 48 wt%) Ni alloy after accumulative roll bonding[END_REF][START_REF] Lachhab | Study of the microstructure and texture heterogeneities of Fe-48wt%Ni alloy severely deformed by equal channel angular pressing[END_REF]. Using three different approaches: Neutron diffraction, Dillamore and KAM approaches, Betanda et al [START_REF] Betanda | Measurement of stored energy in Fe-48%Ni alloys strongly cold-rolled using three approaches: Neutron diffraction, Dillamore and KAM approaches[END_REF] have measured the stored energy in severely cold rolled Fe-48%Ni sheets and they have demonstrated that the neutron diffraction method exhibits the best estimation because it takes into consideration all the dislocation types. Other study about the effect of microalloying elements sulfur and niobium on the formation of {100}<001> Cube texture in cold rolled Fe-48%Ni sheets has shown that sulfur favors and accelerates the nucleation and the development of Cube grains although niobium inhibits theses process [START_REF] Betanda | Influence of sulfur on the recrystallization and {100}<001> Cube texture formation in Fe48% Ni alloys tapes[END_REF]. Both prepared by ARB, Fe-48%Ni and Fe-36%Ni sheets have not exhibited the same texture evolution and higher strength and smaller grains have been found in Fe-48%Ni [START_REF] Boudekhani-Abbas | Texture, microstructure and mechanical properties evolution in Fe-x (x=36 and 48 wt%) Ni alloy after accumulative roll bonding[END_REF]. In particular, the heterogeneity, in different zones of the ECAPed Fe-48%Ni material, has been studied in terms of texture and mechanical properties [START_REF] Lachhab | Study of the microstructure and texture heterogeneities of Fe-48wt%Ni alloy severely deformed by equal channel angular pressing[END_REF]. Shearing deformation has typically enhanced in the top and the lower zone underwent considerably less hardening.

The present work focuses on the structural, microstructural and mechanical changes occurred in Fe-48%Ni (wt.%) alloy processed by ECAP method by means of Electron BackScatter Diffraction (EBSD) and tensile tests. Microstructural of different metallurgical states is characterized in terms of crystallite size, lattice strains and dislocation density using X-ray diffraction (XRD).

Experimental details

Materials and experimental methods

A Fe-48%Ni (wt.%) alloy was received in the form of strips with dimensions of 300×300×1 mm 3 and 300×45×10 mm 3 and then machined into blade specimens of 1 and 10 mm thickness, 10 mm width and 60 mm length. The ECAP process was conducted at room temperature using a die with Φ = 90° and ψ = 17° (Fig. 1a) using a pressing speed of 0.48 mm/s. A stacking of nine superposed samples (S.S) and a bulk billet (B.B) was introduced in the die (Fig. 1b and1c). The molybdenum disulphide (MoS2) was used as lubricant to reduce the friction. S.S and B.B samples were ECAPed twice and once respectively. After each pass of ECAP, peripherals samples, (located in the top and in the bottom of the stack along normal direction (ND), respectively) and central sheet of S.S and three longitudinal sections with 1 mm of thickness from B.B sample were characterized. For the EBSD analysis, sections in the TD-ND plane near the center of the ECAPed sheets were prepared by mechanical polishing to a mirror-like finish and electropolishing with a Struers A2 solution at room temperature.

Microstructure analysis was carried out using a FEG-SEM Supra 55 VP scanning electron microscope operating at 20 kV. EBSD data were analyzed using the TSL Orientation Imaging Microscopy, OIM™ software. The X-ray diffraction measurements of the ECAPed Fe-Ni samples were carried out on a Siemens goniometer system with a Co-Kα radiation.

The mechanical properties of the as received and the ECAPed samples located in the middle of S.S and the central section of B.B were also evaluated at room temperature in the longitudinal direction by tensile tests. The tensile tests were carried out using a Zwick/Roell (Z010) machine with a cross head speed of 4 × 10 -3 mm/s.

Evaluation of X-ray diffraction profiles

The ahkl lattice parameter before and after ECAP was deduced from a linear regression analysis, from each peak, and plotted using the Nilson-Reley (NR) function [23].

NR=(cos2θ/sinθ+cos2θ/θ)/2 (1)
and extrapolated to NR = 0, that is 2θ = 180°. The microstructural parameters such as the lattice parameter, the crystallite grain size (D), the lattice strains () and the dislocation density (D) can be determined from detailed analyses of the X-ray diffraction (XRD) profiles. In the present work, the analysis of the XRD profiles was performed via the Wiliamson-Hall (WH) method widely used in numerous studies [24,[START_REF] Salimon | The character of dislocation structure evolution in nanocrystalline FCC Ni-Co alloys prepared by high-energy mechanical milling[END_REF].

For severely deformed materials, dislocation density, ρ D (m -2 ), can be calculated in terms of the crystallite size, D, the lattice strains, ε, and the Burger's vector, b, according to formula

(2) [START_REF] Vinogradov | Effect of strain path on structure and mechanical behavior of ultra-fine grain Cu-Cr alloy produced by equal-channel angular pressing[END_REF][START_REF] Lachheb | Phase transformations and microstructural properties of nanocrystalline Fe75Si10B10Nb5 alloy synthesized by mechanical alloying[END_REF]:

ρ D = 2√3 <ε 2 > 1/2 D.b
Where "b" is equal to

a√2 2
for the fcc-structure and "a" is the unit cell length.

Results and discussion

X-ray diffraction patterns and stress-strain curves of the as-received materials (in the form of thin and bulk sheets) showed almost the same results.

Where h, k and l are the Miller indices, λ is the wavelength used in the XRD and θhkl is the Bragg angle.

According to formula (3), shifting in peak positions seems to depend certainly on the variation of the lattice parameter "a" resulting from a distortion in the crystal lattice. The introduction of crystalline defects in terms of dislocations and stacking defects during SPD remains the suitable explanation of this observation [START_REF] Lachheb | Phase transformations and microstructural properties of nanocrystalline Fe75Si10B10Nb5 alloy synthesized by mechanical alloying[END_REF][START_REF] Wederni | Structural, microstructural and thermal properties of nanostructured Fe60Al35Sn5 alloy synthesized by mechanical alloying[END_REF].

Table 1 illustrates the evolution of the microstructural parameters in the three studied zones of Also, mean microstrain ε in the B.B samples (0.58%) is greater than the S.S ones (0.31%) and mainly in the higher zone of the material (0.37 and 0.65% respectively for S.S and B.B). By increasing the number of passes, the microstrain rate rises for all sheets. It should be noted that this increase is higher for the lower sheet (+35%) than for the upper one (+22%). In fact, the reduced number of passes does not favor the acquisition of a totally homogeneous microstructure [START_REF] Haj Larbi | Neutron diffraction versus EBSD analysis of the texture in Fe-36%Ni alloy after accumulative roll bonding[END_REF][START_REF] Lachhab | Study of the microstructure and texture heterogeneities of Fe-48wt%Ni alloy severely deformed by equal channel angular pressing[END_REF], as well the effect of Φ and ψ angles and the die geometry, already mentioned by several authors [START_REF] Lachhab | Study of the microstructure and texture heterogeneities of Fe-48wt%Ni alloy severely deformed by equal channel angular pressing[END_REF][START_REF] Grosdidier | On microstructure and texture heterogeneities in single crystals deformed by equal channel angular extrusion[END_REF][START_REF] Beyerlein | Texture evolution in equal channel angular extrusion[END_REF][START_REF] Beyerlein | Non-uniform microstructure and texture evolution during equal channel angular extrusion[END_REF]. Also, it is important to mention that the mean microstrain values after 2 passes remain, however, lower than those found in the B.B bulk sample ECAPed once. Even though the variation was not dramatic, the deformation of the material in the bulk state was greater than the material in the stack form. This explains the high dislocation density values (Table 1) in the case of the bulk samples ECAPed once (2.14 × 10 15 m -2 ) compared with the S.S extruded twice (1.69 × 10 15 m -2 ). This difference can be explained by the slip effect of the stacked sheets during the ECAP tests (Figure 1) which limits the homogenous distribution of strain in different sheets.

Figure 3 shows the conventional tensile curves corresponding to the initial material and the ECAPed samples. Some mechanical parameters derived from tensile tests are also given in Table 2. 2).

Actually, as the material deforms, the grain size decreases which generates greater accumulation of dislocations at the grain boundaries. Since it requires a lot of energy to move dislocations to another grain, these dislocations accumulated along the grain boundary limit the dislocation movement and, therefore, increase the yield strength of the material [32]. The initial material showed an extended plastic region with a uniform deformation of about 43.7% whereas, after one pass, the elongation to failure (A) decreases to 8% and 10.5%, respectively for S.S and B.B samples. For the S.S sample, the A parameter is about 4.4% after two passes. A similar pattern of results was obtained in the Invar Fe-36wt%Ni alloy reinforced by WC nanoparticles and deformed by cold rolling [START_REF] Zheng | Fe-Ni Invar alloy reinforced by WC nanoparticles with high strength and low thermal expansion[END_REF]. In fact, the tensile strength increased by 31% and the elongation reduced from 22.7% to 4.5% after cold rolling of 25% thickness reduction. Moreover, the yield strength and tensile strength of the annealed Invar-WC are increased by 60% and 77%, respectively, compared with the Invar Fe-36wt%Ni, while after cold rolling, the values increased by 40% and 46%, respectively.

Several studies [32,34] have argued that the low elongation may be due to a limited hardening ability that promotes immediately the instability of the plastic domain and the breaking of the sample. These plastic instabilities could be favored by the presence of shear bands and microcracks after ECAP [35,36].

The following section has been an attempt to verify the formation of shear bands and microcracks within the material during ECAP. Thus, a section along [TD, ND] plane in the center of the massive material was studied by EBSD. This choice was made so as to avoid the sliding consequences noted in the case of S.S specimen. Figure 4 shows the orientation and grain boundary maps observed in B.B after its passage through the ECAP matrix. These results go beyond older research [37], showing the formation of these two structures in pure Ni deformed by ECAP at room temperature. As it was reported in this study, the microstructure evolution during ECAP can be described in three main stages. At the beginning, the deformation starts in a homogeneous way then it becomes heterogeneous by the formation of shear bands. The transformation in the deformation type depends on several parameters including the change in the slip systems activity, the local variation in intensity of shear as well as the stress imposed by the die walls. Finally, the formation of the small deformation bands by the fragmentation of fairly homogeneous zones delimited by shear bands. In other words, the formation of shear bands is considered as the response of the material unable to accommodate the continuation of the deformation by the formation of deformation bands. If the deformation continues, shear bands will eventually facilitate the appearance of cracks [37]. Thus, the existence of microcracks has already been demonstrated in Figure 5.

The fracture surfaces of the samples were examined by SEM after tensile tests (Figure 6). The observed surfaces are very irregular. The appearance of certain slip bands was noted especially on the surface of the specimen before ECAP. Typically, dimples appear after nucleation and coalescence of micro-voids in regions with local deformation discontinuities [START_REF] Meyers | Mechanical Behavior of Materials[END_REF]. This confirms the material plasticity and reveals a ductile fracture type. It has been reported that the formation of large and deep dimples initiates from germination of cavities at the grain boundaries due to an accumulation of dislocations [START_REF] Meyers | [END_REF]. Besides, the presence of shallow dimples can be attributed to grain refinement and hardening by severe plastic deformation during ECAP as reported in the literature [40][41][42]. According to Lynch [41], small dimples observed on fracture surfaces indicate that cracking occurs by a localized microvoid-coalescence process along slip bands.

Conclusion

A Fe-48%Ni (wt%) alloy was processed using ECAP technique at room temperature.

After ECAP, the alloy provided a heterogeneous microstructure, along ND in terms of unequal distributions of microstrains rate, crystallite size and dislocation density. Generally, However, despite this limitation, very high yield strength and tensile strength were achieved highlighting the possibility to use the Fe-48% Ni alloy for advanced structural applications in engineering. Owing to the lack of reports about processing this alloy by ECAP, new researches are strongly needed to provide the suitable experimental conditions that respect the hardening ductility ratio.

Figure 1 :

 1 Figure 1: Schematic illustration showing the geometry of the ECAP die (a) and samples after ECAP process (b and c).

Figure 2 (

 2 Figure 2 (a-c) illustrates the X-ray diffraction patterns of the Fe-48%Ni alloy after the ECAP

Figure 2 :

 2 Figure 2: XRD diagrams of the Fe-48% Ni alloy after ECAP (a) 1 pass and (b) 2 passes for

(

  S.S) and (B.B) samples after ECAP. By increasing the number of ECAP passes, the crystallite sizes D of the different sheets decrease and the upper sheet shows the lowest value (25 nm). By comparing the results obtained for S.S and B.B after one pass, it can be noted that the crystallite size of B.B is larger than S.S particularly in the lower zone of the material.

Figure 3 :

 3 Figure 3: Stress-strain curves of Fe-48% Ni alloy before and after ECAP

Figure 4 :

 4 Figure 4: a) Orientations maps (IPF) ({hkl} // (TD-ND) and b) the grain boundary map in the

  maps, there is an alternation of quite wide bands delimited by narrow bands characterized by high concentration of dislocation walls with medium and large misorientation reflecting a localization of the plastic deformation (areas indicated by ellipses in Figures4 a and b). Compared with existing definitions in literature, these narrow bands have the characteristics of shear bands. Another structures highlighted by red arrows (figure4a) corresponding to small parallel bands are formed within the zones delimited by the shear bands. These bands can be considered as deformation bands.

Figure 5 :

 5 Figure 5: Image Quality map observed in the ECAPed Bulk billet.

Figure 6 :

 6 Figure 6: Fracture surfaces morphologies of the Fe-48% Ni alloy before and after ECAP.

  the upper zones underwent the highest hardening (lowest crystallite size and largest rates of microstrains and dislocation density) compared with other ones. Particularly in the case of S.S, sliding effect during ECAP processing offers both an irregular distribution of the deformation rate and a reduction in the hardening of the sample compared to the massive sample B.B. EBSD analyses along ED have revealed cracks and shear bands in the B.B sample after ECAP. Tensile tests have demonstrated a considerable loss of ductility.

Table 1 :

 1 Microstructural parameters of Fe-48% Ni alloy after ECAP.

	Passes number Zones along ND	a (Å)	D (nm)	ε (%)	ρ (10 15 m -2)
		Top	3.591	26.5	0.37	1.53
		Middle	3.60	27.5	0.3	1.31
	N=1 (S.S)
		Bottom	3.602	28	0.26	1.16
		Mean value	3.597	27.33	0.31	1.33
		Top	3.598	25	0.45	1.89
	N=2 (S.S)	Middle	3.583	25.5	0.45	1.81
		Bottom	3.591	27	0.35	1.38

Table 2 :

 2 Some mechanical parameters of Fe-48% Ni alloy before and after ECAP On the other hand, the tensile strength Rm increases from 512 MPa before ECAP to 651 and 739 MPa, respectively, for S.S and B.B after one pass. The second pass reduced the value of Rm to 589 MPa.

	Samples	Elongation to failure A (%) R 0.2 (MPa) R m (MPa)
	N=0	43.7	250	512
	N=1 (S.S)	8	620	651
	N=2 (S.S)	4.4	450	589
	N=1 (B.B)	10.5	690	739

Acknowledgements

This work was supported by the PHC-Maghreb program No. 16MAG03. Authors would like to thank R. Batonnet, Y. Ateba Betanda and T. Waeckerlé from Aperam alloys Imphy society, France, for providing the Fe-48%Ni (wt%) alloy.


Laurence Droz

T Dos Reis

Marina Rabineau

Serge S Berné

G Bellaiche

Quaternary turbidite systems on the northern margins of the Balearic Basin (Western Mediterranean): a synthesis

I-Introduction

The Gulf of Lions is a young passive margin which, because of a high total subsidence rate (250 m/Ma on the outer shelf on the Aude-Hérault interfluve; [START_REF] Rabineau | Un modèle géométrique et stratigraphique des séquences de dépôts quaternaires sur la marge du Golfe du Lion: enregistrement des cycles climatiques de 100 000 ans[END_REF], is very favourable for the registration and preservation of sedimentary sequences from the source (mainly the Rhône River) to the sink (the turbidite sequences in the basin) including the deposition and stacking of strata on the shelf and in the canyons. Since the first publication on the Rhône Deep-Sea Fan [START_REF] Menard | The Rhône Deep-Sea Fan[END_REF], data acquisition and researches on the Plio-Quaternary sedimentation of the Gulf of Lions have been continuous, especially since the 70s', resulting in a large geological and geophysical data base that places the Gulf of Lions among the best known margins in the world. Numerous mainly French and Spanish laboratories have been and are currently involved in these researches, including the sedimentological laboratories of the University of Paris 6 at Villefranche/Mer and Paris, the University of Perpignan, the University of Brest (UBO), Ifremer, the Spanish CNR in Barcelona and the University of Barcelona. A synthesis of these works was proposed by dos [START_REF] Reis | Implications of salt-sediment interactions on the architecture of the Gulf of Lions deep-water sedimentary systems -Western Mediterranean Sea[END_REF] at the scale of the Plio-Quaternary, highlighting the tectonic and halokinetic control on sedimentation.

Recently, special research efforts on the sedimentation in the Gulf of Lions have been brought by the objectives of French and European programmes, including the French GDR Marges (http://gdrmarges.lgs.jussieu.fr) items "Gulf of Lions" and "Siliciclastic and Carbonated Turbidites" and EU projects EUROSTRATAFORM (http://www.soc.soton.ac.uk/CHD/EUROSTRATAFORM) and PROMESS1 (http://promess1.wdc-mare.org). In the framework of these programmes, new data are currently acquired in an effort to obtain key results on sedimentary systems from source to sink on the time-scale of 500 ka, including chronostratigraphic markers and physical parameters on hydrodynamic processes. This paper aims to present a synthesis devoted to the recent (Quaternary) evolution of sedimentary systems around the Balearic Basin of the Western Mediterranean (Fig. 1) with special emphasis on the Gulf of Lions, in order to propose a general framework for newly acquired results.

II-Tectonic, climatic and eustatic history of the margin

The margin is related to large-scale Oligocene extension coeval with the counter clockwise rotation of the Corsican-Sardinian block [START_REF] Olivet | Cinématique de la plaque Ibérique[END_REF]. This rotation has recently been dated between 21 and 15 Ma [START_REF] Speranza | Age of the Corsica-Sardinia rotation and Liguro-Provençal Basin spreading: new paleomagnetic and Ar/Ar evidence[END_REF].

The evolution of the margin led to deposition of thick (several kilometres) marine deposits both on the shelf and on the slope and deep basin from the end of the Miocene to the present. Three major periods characterize this sedimentation: the Messinian Salinity Crisis, the rapid Lower Pliocene sea level rise and the marked climatic cycles during the Upper Pliocene to Quaternary times that lead to cyclic sea-level variations.

The Messinian salinity crisis

Marine deposition was interrupted around 5.5 Ma by an important episode of lowering of sea level and consecutive emersion of the margins of the Mediterranean during the Messinian Salinity Crisis. During this period, the Evaporites Sequence was deposited in the basin, while the margins were severely eroded. The Evaporites Sequence has been partly drilled during DSDP Legs 13 [START_REF] Ryan | Initial Reports of the Deep-Sea Drilling Project[END_REF]) and 42A [START_REF] Hsü | Initial Reports of the Deep-Sea Drilling Project, 42A[END_REF] and ODP Leg 161 [START_REF] Comas | Proc. ODP, Initial Reports Leg 161[END_REF]: it is composed of, from top to bottom, (i) the upper evaporites, of seismically very high amplitude stratified facies, composed of halite, gypsum and marls), (ii) the salt layer, with a transparent seismic facies made of halite, and (iii) the lower evaporites that were never drilled but are possibly of the same composition as the upper evaporites, due to seismic facies similarities Erosion of the emerged margins resulted in the Messinian Unconformity on the shelf and slope, truncating the pre-salt marine series (Burdigalian to Tortonian), and the incision of land-connected deep canyons on the continental shelf and upper slope [START_REF] Gorini | Géodynamique d'une marge passive: le Golfe du Lion (Méditerranée occidentale). 3rd Cycle Thesis[END_REF][START_REF] Gorini | The Late Messinian salinity crisis and Late Miocene tectonism: interaction and consequences on the physiography and post rift evolution of the Gulf of Lions margin[END_REF][START_REF] Lofi | Erosional processes and paleo-environmental changes in the western Gulf of Lions (SW France) during the Messinian Salinity Crisis[END_REF]) that funnelled products of erosion towards the basin while at the same time the lower evaporites were deposited in the deep basin.

The Lower Pliocene rise of sea-level

The paleomorphology at the end of the Messinian was very similar to that observed at present except for the exceptionally low sea-level (of the order of 1000 m). Following this major lowstand event, the re-opening of the Strait of Gibraltar during the Lower Pliocene, together with the global Pliocene rise of sea-level (DSDP Leg 13, [START_REF] Ryan | Initial Reports of the Deep-Sea Drilling Project[END_REF] resulted in a major high sea-level well above the present-day sea-level (about 70 m according to [START_REF] Clauzon | Marine Pliocene Gilbert-type fan deltas along the French Mediterranean coast. A typical infill feature of preexisting subaerial Messinian canyons. 16th IAS Regional Meeting of Sedimentology-5ème Congrès Français de Sédimentologie, Field trip guide book[END_REF]. The ensuing high sealevel lasted about 1 Ma.

Depending on the morphology of the borderlands, the sea entered widely on former land areas and formed deep rias of various lengths inside the main rivers of the margin (for example reaching Lyon in the Rhône ria, 260 km upslope from the present-day shore line). The combination of the Messinian fluvial incision and the unusually high sea level of the Lower Pliocene led to a very specific paleo-geography with no shelves, deeply incised rias, narrow and deep marine basins fed by a mountainous hinterland with high relief and a high sediment supply [START_REF] Clauzon | Marine Pliocene Gilbert-type fan deltas along the French Mediterranean coast. A typical infill feature of preexisting subaerial Messinian canyons. 16th IAS Regional Meeting of Sedimentology-5ème Congrès Français de Sédimentologie, Field trip guide book[END_REF]. Infilling of the rias was realised by prograding Gilbert-type fan-deltas [START_REF] Clauzon | Marine Pliocene Gilbert-type fan deltas along the French Mediterranean coast. A typical infill feature of preexisting subaerial Messinian canyons. 16th IAS Regional Meeting of Sedimentology-5ème Congrès Français de Sédimentologie, Field trip guide book[END_REF], while the deepest part of the Mediterranean basin was the site of condensed deposition, characterized by thin marine shales enriched with planktonic elements (DSDP Leg 13, site 132, [START_REF] Ryan | Initial Reports of the Deep-Sea Drilling Project[END_REF].

The Upper Pliocene to Quaternary glacio-eustatic fluctuations

Extreme climatic modifications generated by fluctuations of ice development in the Northern Hemisphere followed the anomalous Lower Pliocene event. Upper Pliocene to Quaternary sedimentation became mainly controlled by glacio-eustatic sea-level changes related to the Milankovitch cyclicities. During the Pleistocene the dominant cyclicity changed (from 40 ka to 100 ka) and was accompanied by a change in sea-level cycle amplitudes (from 50 m to 100 m). This change, called the Mid-Pleistocene Revolution, generally occurs at stage 22 (around 800-900 ka, e.g. [START_REF] Paillard | Glacial cycles: toward a new paradigm[END_REF][START_REF] Ruddiman | Paleoenvironmental results from North Atlantic sites 607 and 609[END_REF]. Sedimentation in the Gulf of Lions became dominated by terrigeneous deposition brought from the main rivers to the basin (Fig 1) through turbidite systems. Sedimentary input principally originated from the Alps that were drained by the Rhône River and its tributaries. Input from the Massif Central [START_REF] Chamley | Recherches sur la sédimentation argileuse en Méditerranée[END_REF] and Pyrenees remained low. Quaternary fluvial erosion was powerful, as attested by the depth of the rivers and was variably enhanced by continental uplift [START_REF] Clauzon | Marine Pliocene Gilbert-type fan deltas along the French Mediterranean coast. A typical infill feature of preexisting subaerial Messinian canyons. 16th IAS Regional Meeting of Sedimentology-5ème Congrès Français de Sédimentologie, Field trip guide book[END_REF].

The absence of detailed chronostratigraphic data in the Gulf of Lions is a great gap for the full understanding of its sedimentary evolution and of the factors that control this evolution. Industrial borehole GLP1 (e.g. in ;Droz 1999;[START_REF] Reis | La tectonique salifère et son influence sur l'architecture sédimentaire quaternaire de la marge du Golfe du Lion -Méditerranée Occidentale[END_REF][START_REF] Reis | Implications of salt-sediment interactions on the architecture of the Gulf of Lions deep-water sedimentary systems -Western Mediterranean Sea[END_REF] provided the depth of the Pliocene/Pleistocene boundary that was correlated regionally on industrial HR multichannel seismic profiles (see Fig. 1 for location of GLP1). On seismic sections, Pliocene turbidites are identified at the base of slope, under the Petit-Rhône Fan [START_REF] Droz | Les éventails sous-marins profonds : structure et évolution sédimentaire, à partir de l'étude comparative de trois édifices, l'Eventail du Rhône, la Ride du Var, le Cône de l[END_REF]) and all along the margin (dos Reis 2001; dos [START_REF] Reis | Implications of salt-sediment interactions on the architecture of the Gulf of Lions deep-water sedimentary systems -Western Mediterranean Sea[END_REF] as small channel/levee systems grouped into a basal complex of channelized units, with little architectural organisation and distal seismic character when compared to the Quaternary deposits (see below). [START_REF] Droz | Rhône deep-sea fan: morphostructure and growth pattern[END_REF] proposed that the huge Pleistocene channel/levee complexes on top of the distal Pliocene turbidites at the base of slope was related to a strong progradation of the margin during the Quaternary, as expected from glacio-eustatic changes of sealevel. Pliocene turbidites probably used previous Messinian canyons/fluvial incisions observed on the isochron and isobath map of the Messinian surface [START_REF] Gorini | Géodynamique d'une marge passive: le Golfe du Lion (Méditerranée occidentale). 3rd Cycle Thesis[END_REF][START_REF] Guennoc | Histoire géologique du Golfe du Lion et cartographie du rift oligoaquitanien et de la surface messinienne[END_REF][START_REF] Gorini | The Late Messinian salinity crisis and Late Miocene tectonism: interaction and consequences on the physiography and post rift evolution of the Gulf of Lions margin[END_REF]. The initiation of turbidite deposition during the Pliocene is not age-constrained, but probably occurred early as suggested by their identification close to the Messinian upper evaporites [START_REF] Droz | Les éventails sous-marins profonds : structure et évolution sédimentaire, à partir de l'étude comparative de trois édifices, l'Eventail du Rhône, la Ride du Var, le Cône de l[END_REF]. The thickening of Pliocene sediments down slope from the Marti Canyon and Rhône Canyon (dos Reis, unpublished data) attests that they were dominant input paths to the basin at that time.

III-Quaternary gravity sedimentation of the northern Balearic Basin

During the Quaternary, the Gulf of Lions' slope and rise have been the site of thick sedimentary accumulations deposited by gravity processes (dos Reis 2001; Droz 1991) (Fig. 2). Several huge allochtonous unconformable transparent bodies interpreted as mass-transport deposits also attest to the importance of repeated periods of instability during the Quaternary.

Present-day morphology of the shelf and slope of the Gulf of Lions

The newly published bathymetric map of the Gulf of Lions [START_REF] Berné | Carte morpho-bathymétrique du Golfe du Lion. Ifremer-Région Languedoc-Roussillon[END_REF] together with the interpretation of seismic data enabled a detailed morpho-sedimentary description of the margin and an origin for the observed sedimentary features [START_REF] Berné | Notice de la carte morpho-bathymétrique du Golfe du Lion[END_REF]. The shelf of the Gulf of Lions is 80 km wide in its central part and less than 20 km wide at its western and eastern limits. The outer shelf is affected by two main types of topographical features that are markers of sea-level changes during and after the Last Glacial Maximum (LGM): (i) a shore parallel main break in slope of regional extent occurs from 98-112 m (depending on the location on the shelf) down to about 120-128 m creating a clear and continuous step, which is interpreted as isotopic stage 2 sandy shoreline remnants; (ii) shore transverse elongated features, either lows or bulges, are representative of the retreat path of paleo-river courses during the deglacial sea-level rise [START_REF] Torres | Analyse détaillée du transfert de sediment du continent vers le basin: le Quaternaire terminal au large du delta du Rhône (Méditerranée nord-occidentale). 3 rd Cycle Thesis[END_REF][START_REF] Rabineau | Un modèle géométrique et stratigraphique des séquences de dépôts quaternaires sur la marge du Golfe du Lion: enregistrement des cycles climatiques de 100 000 ans[END_REF][START_REF] Marsset | Late Pleistocene-Holocene deposits of the Rhône inner continental shelf (France): detailed mapping and correlation with previous continental and marine studies[END_REF][START_REF] Berné | Carte morpho-bathymétrique du Golfe du Lion. Ifremer-Région Languedoc-Roussillon[END_REF][START_REF] Berné | Notice de la carte morpho-bathymétrique du Golfe du Lion[END_REF]. During the LGM, the Petit-Rhône River was connected to the Petit-Rhône, Marti and Hérault Canyons, and the Pyrenean Rivers were connected to the Aude (also called Bourcart) and Lacaze-Duthiers Canyons to the west (Figs. 1,3). The connection of rivers has also been demonstrated by [START_REF] Baztan | Formation et évolution des canyons sous-marins du Golfe du Lion: relations avec les cycles glacio-eustatiques[END_REF] and [START_REF] Baztan | Axial incision: the key to understand submarine canyon evolution[END_REF] by the existence of an active axial incision in the Marti, Hérault, Aude, Lacaze-Duthiers and Cap Creus canyons.

The continental slope is characterized by strong incisions by canyons (Fig. 3). Three groups of canyons can be distinguished:

(i) To the west, the Pyreneo-Languedocian canyons (Cap Creus, Lacaze-Duthiers, Pruvost, Aude, Hérault Canyons from west to east) and Marti and Catherine-Laurence Canyons form a converging network that joins the Sète Canyon at various depth. Seismic data revealed that these canyons were more or less parallel to each other and oriented approximately N-S, parallel to the slope gradient during the Early Quaternary and that the converging pattern presently observed was acquired recently (very Late Pleistocene, maybe between 150 ka and 20 ka) [START_REF] Droz | Turbidites of the Western Golfe du Lion: relationships between Pyreneo-Languedocian and Rhone inputs[END_REF][START_REF] Reis | Implications of salt-sediment interactions on the architecture of the Gulf of Lions deep-water sedimentary systems -Western Mediterranean Sea[END_REF]). In the basin, the Pyreneo-Languedocian Canyons fed an asymmetrical turbidite system, the Pyreneo-Languedocian Ridge.

(ii) To the east of the Gulf of Lions, the Grand-Rhône, Marseille/Planier and Cassidaigne Canyons (from west to east) are NW-SE oriented and are followed at the base of slope by nearly W-E valleys that are bordered on their right hand side by elongated ridges of turbidite origin.

(iii) In the central part, between these two groups of canyons, the Petit-Rhône Canyon has a contrasting morphology with a meandering inner erosional thalweg along its entire length. Meandering inner thalwegs are not known elsewhere in the Gulf of Lions, except in the very upper course of the Aude Canyon where a meandering axial incision is present [START_REF] Berné | Notice de la carte morpho-bathymétrique du Golfe du Lion[END_REF][START_REF] Gaudin | Sédimentation récente dans les têtes des canyons de Capbreton (Golfe de Gascogne) et Bourcart (Golfe du Lion). 9 ème Congrès de l'Association des Sédimentologistes Français[END_REF][START_REF] Baztan | Axial incision: the key to understand submarine canyon evolution[END_REF]. The Petit-Rhône Canyon, presently connected to the Neochannel (see below), has been the only path for feeding alpine detritic material towards the Petit-Rhône Deep Sea Fan during the Quaternary.

The turbidite systems in and around the Balearic Basin

Two thick turbidite systems, the Petit-Rhône Fan and the Pyreneo-Languedocian Ridge, observable on the isopach map of the Quaternary of the Gulf of Lions (Fig. 2

The Petit-Rhône Fan

The Petit-Rhône Fan [START_REF] Droz | L'éventail sous-marin profond du Rhône (Golfe du Lion): grands traits morphologiques et structure semi-profonde[END_REF][START_REF] Droz | Les éventails sous-marins profonds : structure et évolution sédimentaire, à partir de l'étude comparative de trois édifices, l'Eventail du Rhône, la Ride du Var, le Cône de l[END_REF][START_REF] Coutellier | Mise en Evidence et Rôle des Mouvements Gravitaires dans l'Evolution de la Marge Continentale: exemple des Marges du Golfe du Lion et de la Provence Occidentale[END_REF][START_REF] Torres | Analyse détaillée du transfert de sediment du continent vers le basin: le Quaternaire terminal au large du delta du Rhône (Méditerranée nord-occidentale). 3 rd Cycle Thesis[END_REF][START_REF] Reis | La tectonique salifère et son influence sur l'architecture sédimentaire quaternaire de la marge du Golfe du Lion -Méditerranée Occidentale[END_REF][START_REF] Droz | Rhône deep-sea fan: morphostructure and growth pattern[END_REF] is the largest turbidite system in the Gulf of Lions. Situated in the central part of the Gulf, it represents an accumulation of 3600 m of turbidites and mass-transport deposits, the Quaternary fan being about 1300 m thick (Fig. 2). The fan was fed mainly by alpine inputs through the Rhône River and Delta and the Petit-Rhône canyon.

The Quaternary Petit-Rhône Fan is an overall symmetrical feature extending to at least 2850 m water depth where channels have been imaged [START_REF] Droz | Interrelationships between the sedimentary systems in the Western Mediterranean (Gulf of Lions and Balearic Abyssal Plain): preliminary results from PROGRES cruise (EUROSTRATAFORM programme)[END_REF]. At 2750 m water depth, cores sampled coarse turbidites [START_REF] Méar | Séquences et unités sédimentaires du glacis rhodanien (Méditerranée Occidentale). 3 rd Cycle Thesis[END_REF]). The fan is composed of stacked channel/levee systems characterized by typical lens shaped seismic bodies associated to stratified facies in levees and high amplitude chaotic facies in a central channel. The channel/levee systems are grouped into three main complexes (1-lower, 2-middle and 3-upper complexes from the oldest to the youngest) overlapping each other while avulsing westwards, and shows a basinward divergent architecture from a common landward point source, the Petit-Rhône Canyon (Fig. 3). Although absolute ages are not available for these turbidite complexes, they are supposed to accumulate during Quaternary lowstands of sea level. Based on this assumption and on the paleodrainage reconstruction on the shelf during the Quaternary [START_REF] Monjuvent | Paléogéographie quaternaire, planches Q1 à Q4[END_REF], a chronostratigraphic history was proposed by [START_REF] Bellaiche | Detailed morphology, sedimentary structure and evolution of the continental margin of the Western Provençal Bassin (south of France) since late Miocene[END_REF] that places the transition from the middle complex to the upper complex during the Mindel/Riss interglacial, i.e. a high sea-level dated between 200 to 500 ka, depending on correlations between continental and marine studies [START_REF] Van Eysinga | Geological time table-3 rd edition[END_REF][START_REF] Kukla | Plio-Pleistocene megacycles: record of climate and tectonics[END_REF].

During the Late Quaternary, the Rhône Fan underwent a last westward avulsion of its main channel and built partly on its right levee and partly on a transparent mass-transport body (see below) the lobate Neofan [START_REF] Droz | Rhône deep-sea fan: morphostructure and growth pattern[END_REF][START_REF] Torres | Deep-sea avulsion and morphosedimentary evolution of the Rhône Fan Valley and Neofan during the Late Quaternary (northwestern Mediterranean Sea)[END_REF]) (Fig. 4). The Neofan includes 2 main units [START_REF] Bonnel | Faciès sismiques, lithologiques et modes de mise en place du néofan du Rhône et du corps discordant occidental du Golfe du Lion (Méditerranée Occidentale)[END_REF][START_REF] Bonnel | Architecture and depositional pattern of the Rhône Néofan and recent gravity activity in the Gulf of Lions (Western Mediterranean)[END_REF]), a basal one (the Neofan Chaotic Unit) made of high amplitude seismic facies of about 50 m of thickness, interpreted as an avulsion lobe similar to the HARPs of the Amazon Fan (e.g. [START_REF] Pirmez | Sandy turbidite successions at the base of channel-levee systems of the Amazon Fan revealed by FMS and cores: unraveling the facies architecture of large submarine fans[END_REF], and an upper unit (the Neofan Transparent Unit) about 30 m thick, representing a small channel/levee system, seismically transparent on sparker data, and stratified on chirp data, that prograded on its avulsion lobe (Fig. 4). The Neofan extends southwestwards for at least 100 km down from the Neochannel bifurcation point to a distal area where several generations of lobate features interpreted as terminal lobes are present [START_REF] Droz | The southern prolongation of the Rhône Neofan from recent high-resolution data[END_REF]). The sea-floor on the western part of the Neofan is affected by giant scours that are erosional features typical of a channel/lobe transition zone according to [START_REF] Kenyon | Scour holes in a channel-lobe transition zone on the Rhône Cone[END_REF] and are supposed to originate from hydraulic jump processes of the turbidity currents at the termination of the Neochannel [START_REF] Kenyon | Scour holes in a channel-lobe transition zone on the Rhône Cone[END_REF][START_REF] Bonnel | Architecture and depositional pattern of the Rhône Néofan and recent gravity activity in the Gulf of Lions (Western Mediterranean)[END_REF].

AMS radiocarbon dating indicates that the starvation of the Neofan occurred at 15.1 ka B.P. (in this paper all the ages younger than about 20 ka are expressed in 14 C time scale; Table 1 provides the corresponding calibrated ages and reservoir correction age when known) when it became inactive. Upstream of the avulsion point, the starvation and inactivity of the fan seems to occur 4 ka later at 11 ka B.P [START_REF] Bonnel | Architecture and depositional pattern of the Rhône Néofan and recent gravity activity in the Gulf of Lions (Western Mediterranean)[END_REF]. The onset of the Neofan is still unknown as it is too thick (~ 80 m) to be reached by conventional coring. From pollen analysis in a core located on the right levee of the Neochannel, [START_REF] Beaudouin | The Late-Quaternary climatic signal recorded in a deep-sea turbiditic levee (Rhône Neofan, Gulf of Lions, NW Mediterranean): palynological constraints[END_REF] provided an estimated age of 18.6 ka B.P. at 8.5 m inside the upper unit of the Neofan that allowed [START_REF] Bonnel | Architecture and depositional pattern of the Rhône Néofan and recent gravity activity in the Gulf of Lions (Western Mediterranean)[END_REF] to calculate a mean deposition rate (~ 1m/ka) and a linearly extrapolated maximum age of 100 ka B.P. for the occurrence of the avulsion and beginning of growth of the Neofan. However, turbidite deposition rate is not linear but is highly discontinuous with short periods of accelerated deposition (for example up to 3 to 4 m/ka in the Amazon Fan according to [START_REF] Showers | Isotopic stratigraphy of Amazon fan sediments[END_REF]) alternating with periods of slower hemipelagic deposition. Therefore the use of mean deposition rates is highly unreliable, and the proposed age is probably greatly overestimated. Previously, [START_REF] Méar | Séquences et unités sédimentaires du glacis rhodanien (Méditerranée Occidentale). 3 rd Cycle Thesis[END_REF] had indicated that turbidite sedimentation on levees stopped at about 20 ka B.P. in water depths greater than 2000 m, i.e. downslope from the Neochannel bifurcation point. This starvation of the fan beyond -2000 m possibly relates to the shift of the Petit-Rhône fan depocenters towards the Neofan. Admitting this age as indicative of the approximate onset of the Neofan, a much higher mean deposition rate is calculated (16 m/ka) that is also not accurate, but is probably closer to the real deposition rate of the avulsion lobe that accounts for more than 60 % of the Neofan thickness.

The Pyreneo-Languedocian Ridge

In the western corner of the Gulf of Lions, the Pyreneo-Languedocian Ridge is a 900-1000 m thick sediment accumulation at the base of the western slope that connects with the Pyreneo-Languedocian plus the Marti and Catherine-Laurence Canyons (Fig. 3). [START_REF] Berné | Canyons et processus sédimentaires récents sur la marge occidentale du Golfe du Lion. Premiers résultats de la campagne Calmar[END_REF] and [START_REF] Droz | Recent sedimentary events in the western Gulf of Lions (Western Mediterranean)[END_REF] proposed that the Pyreneo-Languedocian Ridge is an asymmetrical feature located on the right-hand side of the Sète Valley, with strong similarities to the Var Ridge on the Provençal margin [START_REF] Savoye | Plio-Pleistocene evolution of the Var deep-sea fan off the French Riviera[END_REF]) and was fed by sediment funnelled in the converging network of the Pyreneo-Languedocian canyons. More recently, dos Reis et al. (2004a[START_REF] Reis | Implications of salt-sediment interactions on the architecture of the Gulf of Lions deep-water sedimentary systems -Western Mediterranean Sea[END_REF] considered a two-stage building, an early fan-like building period, in relation to the abandoned N-S lower courses of the Pyreneo-Languedocian canyons and a later asymmetrical ridge-like building by overflow from the Sète Canyon receiving the Pyreneo-Languedocian canyons.

Shelf studies have shown that detritic sediments were supplied to the ridge partly by the Pyreneo-Languedocian rivers (Tech, Têt, Agly, Aude, Orb, Hérault, from southwest to northeast), and partly the Rhône River that not only fed the Petit-Rhône canyon but also the Marti Canyon and maybe the Hérault canyon during the LGM [START_REF] Berné | Canyons et processus sédimentaires récents sur la marge occidentale du Golfe du Lion. Premiers résultats de la campagne Calmar[END_REF][START_REF] Berné | Notice de la carte morpho-bathymétrique du Golfe du Lion[END_REF]. According to [START_REF] Baztan | Formation et évolution des canyons sous-marins du Golfe du Lion: relations avec les cycles glacio-eustatiques[END_REF] the Sète canyon has also been connected to the Rhône River.

The Pyreneo-Languedocian complex is restricted in space, extending from about 2000 to 2500 m water depth, over approximately 50 km in a NW-SE direction. It is made of stratified undulating seismic facies interpreted as migrating sediment waves (e.g. Jallet and Giresse 2005) that aggraded vertically all along the Quaternary, the Sète valley undergoing only a faint progressive lateral migration towards the east. Although direct dating information are lacking, geometrical relationships from seismic profiles indicate that building of the ridge was probably contemporaneous to the upper complex of the Petit-Rhône Fan and therefore is inferred to be Upper Pleistocene in age [START_REF] Bellaiche | Detailed morphology, sedimentary structure and evolution of the continental margin of the Western Provençal Bassin (south of France) since late Miocene[END_REF], i.e. around 200-500 ka. In contrast to the Petit-Rhône Fan, no channel/levee systems are observable during the Pliocene, suggesting that the activity of the Pyreneo-Languedocian canyons began later than the Petit-Rhône Canyon and Deep Sea Fan.

The area located at the outlet of the Sète and La Fonera Canyons (on the Catalan Margin) remained active very late during the Quaternary (Late Pleistocene-Holocene), while the Petit-Rhône Fan and Neofan were already abandoned [START_REF] Droz | Recent sedimentary events in the western Gulf of Lions (Western Mediterranean)[END_REF]. This recent activity is highlighted by thin low backscattering patchy lobes at the outlet of both canyons, in which cores recovered beds of silts to fine sands intercalated within a 2.3 m thick unit of foraminiferal and nannofossils oozes [START_REF] Bonnel | Architecture and depositional pattern of the Rhône Néofan and recent gravity activity in the Gulf of Lions (Western Mediterranean)[END_REF]. In both cases, the hemipelagic unit was deposited since the abandonment of the Neofan at 15.1 ka B.P. and radio-carbon ages at the top of the hemipelagic unit (2.5 ka B.P.) allowed estimation of an age of 8 ka B.P. in the Sète Lobe and 4 ka B.P. in the La Fonera Lobe for the last events of sand deposition, by linear interpolation using mean sedimentation rates [START_REF] Bonnel | Architecture and depositional pattern of the Rhône Néofan and recent gravity activity in the Gulf of Lions (Western Mediterranean)[END_REF]) (Figs. 3 and5).

Other turbidite systems around the Balearic Basin

Eastern part of the Gulf of Lions and Provençal margin.

At the eastern corner of the Gulf of Lions, the Grand-Rhône, Marseille/Planier and Cassidaigne Canyons from west to east, gave rise to elongated turbidite ridges [START_REF] Droz | Les éventails sous-marins profonds : structure et évolution sédimentaire, à partir de l'étude comparative de trois édifices, l'Eventail du Rhône, la Ride du Var, le Cône de l[END_REF][START_REF] Reis | La tectonique salifère et son influence sur l'architecture sédimentaire quaternaire de la marge du Golfe du Lion -Méditerranée Occidentale[END_REF]dos Reis et al. 2004b), extending for up to 90 km parallel to the south Provençal margin. Except for the Cassidaigne Canyon, which does not have a clear relationship with a river, both the other canyons were fed with Alpine detrital input from the Grand-Rhône outlet of the Rhône River, to the East of the Petit-Rhône outlet. The lower course of the canyons are deflected towards the east, in response to halokinetic controls (dos Reis et al. 2004b) rather than coriolis controls and bordered on their southern side by the ridges.

Detailed analysis of the architecture of the ridges showed that the current highly asymmetrical ridge-like morphology is salt-tectonically imposed and not hydrodynamically dependent and therefore is not representative of the true architectural style of the depocenters. dos Reis et al. (2004b) showed that along the Marseille/Planier Valley, overbanking of turbidity currents occurred on both sides, but that, on the northern side, syn-sedimentary activity of growth faults created hemi-grabens which trapped turbidites, preventing the typical levee morphology from developing on the left levee. The left levee of the Grand-Rhône Valley was also shown to be inhibited by a local buttress provided by the prominent Marseille sedimentary ridge, up to about 600 m high.

Eastern Iberian margin.

To the west of the Balearic Basin, short canyons and gullies are cut into the continental shelf and slope of the Catalan margin [START_REF] Amblas | The ocean margin northeast of Iberia: a complex sedimentary system draining into the deep basin[END_REF]), but no thick turbidite systems are described. The main river that delivered sediments to the basin is the Ebro River (Fig. 1) that contributed to the building of a turbidite system made of short channel/levee systems, debris flows and apron deposits on the upper slope of the Ebro margin [START_REF] Alonso | Late Quaternary sedimentation patterns of the Ebro turbidite systems (northwestern Mediterranean): two styles of deep-sea deposition[END_REF][START_REF] Alonso | Architecture of modern turbidite systems in different geologic settings on the Spanish margins (NW and SW Mediterranean Sea)[END_REF][START_REF] Alonso | Sea valleys and related depositional systems in the Gulf of Lions and Ebro continental margins[END_REF].

The main deep turbidite system on the eastern Iberian margin is the Valencia Fan. The Valencia Valley has a tectonically controlled southwest/northeast course, between the Iberian continental slope and the Balearic Islands until it merges into the open Balearic Basin where it is deflected toward the southeast (Figs. 1,3). The Valencia Valley is not connected to a river but collects inputs from tributaries that dissect the Iberian margin on its northern side, including the Ebro inputs.

The Valencia Valley is a long leveed valley of the mid-ocean submarine valley type [START_REF] Canals | The Ebro continental margin, Western Mediterranean Sea: Interplay between canyon-channel systems and mass wasting processes[END_REF] that ends with a terminal lobe on the Balearic Plain east of the Minorca Island (Palanques et al. 1995). The Valencia lobe extends more than 150 km downdip and is a maximum of 25 km across (Fig. 3). Although not dated, it appears to be a very recent feature (Late Pleistocene-Holocene) as suggested by fresh bedforms and erosional features and sandy turbidites containing pteropod shells of Holocene age, recovered in cores [START_REF] Morris | Downstream changes of large-scale bedforms in turbidites around the Valencia channel mouth, north-west Mediterranean: implications for palaeoflow reconstruction[END_REF].

Mass-movement deposits

In addition to the turbidite systems, gravity deposits are present on the northern and western margins of the Balearic Basin, as broad and thick (up to 75 m thick for a volume of up to 200 km 3 ) unconformable transparent mass-transport deposits.

In the Gulf of Lions, the western and eastern mass-transport bodies (representing an estimated total volume of 370 km 3 ) truncate both levees of the Petit-Rhône Fan (Bellaiche et al. 1986) (Figs. 3, 4). The western mass-transport body extends along 150 km at the base of the Gulf of Lions slope between the Pyreneo-Languedocian Ridge and the Petit-Rhône Fan. It is up to 120 ms two-way time (about 100 m) thick in its upslope part and represents an estimated volume of 217 km 3 . Because of its transparent seismic facies, erosional basal surface and allochtonous origin, this mass-transport body is interpreted as a debris flow and was previously named the "Western Debris-Flow" [START_REF] Droz | Rhône deep-sea fan: morphostructure and growth pattern[END_REF]. Direct dating is not yet available for this body. However, it is intercalated between the Petit-Rhone Fan (below) and the Neofan (above). Considering that its onset has been most likely of very short duration (instantaneous at the geological time scale), we can infer that instability processes occurred around 20 ka B.P., between the end of activity of the Petit-Rhône Fan south from the Neochannel bifurcation point [START_REF] Méar | Séquences et unités sédimentaires du glacis rhodanien (Méditerranée Occidentale). 3 rd Cycle Thesis[END_REF] and the onset of the Neofan (see above).

On the Ebro Margin, the Columbretes Slide [START_REF] Field | Pliocene-Pleistocene growth of the Rio Ebro margin, northeast Spain: a prograding-slope model[END_REF] later renamed the Big'95 debris flow by [START_REF] Canals | The Ebro continental margin, Western Mediterranean Sea: Interplay between canyon-channel systems and mass wasting processes[END_REF] and [START_REF] Lastras | Seafloor imagery from the BIG'95 debris flow, western Mediterranean[END_REF] is identified on sub bottom profiles as a transparent sediment body located on the Ebro slope, base of slope and inside the Valencia Valley. This transparent body shows thickness ranging from 153 m near the source area to less than 15 m in its distal depositional area and extends over a surface of about 2000 km 2 involving a sediment volume greater than 26 km 3 [START_REF] Lastras | Seafloor imagery from the BIG'95 debris flow, western Mediterranean[END_REF][START_REF] Lastras | Characterisation of the recent BIG'95 debris flow deposit on the Ebro margin, Western Mediterranean Sea, after a variety of seismic reflection data[END_REF]. From radio-carbon dating, the minimum age of the debris flow is about 10.3 ka B.P. Other indications of recent instability processes are also mentioned on both sides of the Valencia Valley by [START_REF] Alonso | A deep-sea channel in the Northwestern Mediterranean Sea: morphology and seismic structure of the Valencia Channel and its surroundings[END_REF].

Altogether, these allochtonous bodies, of Late Quaternary age, although they did not occur synchronously along the margins of the Balearic Basin, represent an estimated minimum volume of 400 km 3 , attesting to major episodes of instability at the end of the Quaternary (around the LGM and the following deglacial period).

Similar but buried mass-transport deposits are known in the Gulf of Lions and on the Iberian margin. Under the Petit-Rhône Fan, mass-transport bodies are interstratified between the middle and upper complexes (complexes 2 and 3), on both levees of the middle complex and inside the channel [START_REF] Droz | Rhône deep-sea fan: morphostructure and growth pattern[END_REF] (Fig. 4), suggesting that sediment instability has been a recurrent phenomenon throughout the Quaternary. In the present state of knowledge, without age assignment, the origin, age and recurrence during the Quaternary of such huge mass-transport events cannot be specified. On the Catalan margin, [START_REF] Lastras | Characterisation of the recent BIG'95 debris flow deposit on the Ebro margin, Western Mediterranean Sea, after a variety of seismic reflection data[END_REF] identified several debris flow events under the Big'95 debris flow. The biggest one rests on a seismic reflector (G) that separates the Pliocene from the Quaternary deposits, and is therefore probably older than those in the area of the Rhône Fan where the buried mass-transport deposit rests on the middle complex and would therefore be Middle Quaternary in age (see above).

The Balearic Abyssal Plain "Megaturbidite" [START_REF] Rothwell | Low sea-level emplacement of a very large Late Pleistocene "megaturbidite" in the western Mediterranean Sea[END_REF][START_REF] Rothwell | Low sea-level emplacement of megaturbidites in the western and eastern Mediterranean Sea[END_REF] described an approximately 9 m thick seismically transparent unit of turbidites, called the "Megaturbidite", at about 10 m below seafloor infilling the deepest part of the Balearic Basin. This megaturbidite was interpreted as a single depositional event [START_REF] Rothwell | Low sea-level emplacement of a very large Late Pleistocene "megaturbidite" in the western Mediterranean Sea[END_REF]. However more recent seismic data provided evidences for possibly at least 2 successive episode of deposition [START_REF] Droz | Interrelationships between the sedimentary systems in the Western Mediterranean (Gulf of Lions and Balearic Abyssal Plain): preliminary results from PROGRES cruise (EUROSTRATAFORM programme)[END_REF]. This unit is thought to extend in the centre of the basin, bounded by the 2800 m isobath, representing a total estimated surface of 60 000 km 2 and a volume of about 500 km 3 . Recent bathymetric and seismic survey [START_REF] Droz | Interrelationships between the sedimentary systems in the Western Mediterranean (Gulf of Lions and Balearic Abyssal Plain): preliminary results from PROGRES cruise (EUROSTRATAFORM programme)[END_REF] refined the north-western boundary of the transparent unit to a water depth of about 2850 m. This megaturbidite was sampled by 5 Calypso cores taken with the R/V Marion Dufresne (cruise 81, 1995), up to 32 m long, located on a north-south transect from seaward of the Petit-Rhône Fan to the Algerian Margin (Fig. 1). The megaturbidite is composed of AMS radio-carbon dating in hemipelagic intervals bounding the megaturbidite, gave ages of about 17.6 ka B.P. at the top and about 20.3 ka B.P. at the bottom [START_REF] Rothwell | Low sea-level emplacement of a very large Late Pleistocene "megaturbidite" in the western Mediterranean Sea[END_REF][START_REF] Hoogakker | Variations in terrigenous dilution in western Mediterranean Sea pelagic sediments in response to climate change during the last glacial cycle[END_REF], indicating that the megaturbidite event was of short duration (2 ka) and deposited sediments at a rate of 3 m/ka during the Last Glacial Maximum (beginning of stage MIS2).

The megaturbidite is included into a lithological unit at least 30 m thick made of upward fining sequences (basal sands, silt to thick structureless muds) interpreted as a succession of ponded turbidite deposits, intercalated with thinner bioturbated foraminifer-rich mud intervals of hemipelagic origin. In the Calypso cores, turbidites account for about 90% of the sediment column, with a percentage increase towards the north. This northward evolution is also emphasized by the coarsening of basal sands in the megaturbidite in the northward direction, suggesting that sediments in the megaturbidite possibly originated from the northern parts of the basin (Gulf of Lions via the Petit-Rhône or Sète Canyon, Catalan Margin, Ligurian Margin via the Var Valley or Corsican Margin). Preliminary analysis of recent seismic data [START_REF] Ferrer | Chronologie relative des systèmes turbiditiques dans la partie distale du Golfe du Lion (Méditerranée Occidentale) sur les derniers 200.000 ans[END_REF]) did not reveal any physical continuity of the megaturbidite with any of the northern and western seismic bodies (neither the Rhône Fan, the Western Mass-Transport Deposit, nor the Valencia Fan). Very high-resolution seismic profiles indicate that the transparent unit is intercalated between the distal Rhône Fan (that became inactive around 20 ka B.P. at water depth greater than 2000 m, [START_REF] Méar | Séquences et unités sédimentaires du glacis rhodanien (Méditerranée Occidentale). 3 rd Cycle Thesis[END_REF]) and the Valencia lobe that is Late Pleistocene-Holocene according to [START_REF] Limonov | Deep-sea depositional systems of the Western Mediterranean and mud volcanism on the Mediterranean Ridge; Initial results of geological and geophysical investigations during the fourth UNESCO-ESF "Training-Through-Research" cruise of R/V Gelendzhik[END_REF]. More precise origin for the material accumulated in the megaturbidite remains unknown. However, in the basinal turbidites that cover the megaturbidite, analysis of clay minerals of sediments collected in short cores from the Balearic Basin [START_REF] Méar | Séquences et unités sédimentaires du glacis rhodanien (Méditerranée Occidentale). 3 rd Cycle Thesis[END_REF] indicates a rhodanian origin of the inputs, possibly through the Grand-Rhône River and canyon head where the suspended material is concentrated during the Holocene [START_REF] Aloïsi | Origine et rôle du néphéloïde profond dans le transfert des particules au milieu marin. Application au Golfe du Lion[END_REF].

IV-Quaternary sedimentary evolution of the northern Balearic Basin

This synthesis allows a recapitulation of the sedimentary evolution of the northern Balearic Basin during the Quaternary. The known or inferred ages for the different sedimentary systems are summarized in Fig. 5.

Pleistocene

Following the building of the Pliocene basal complex of the Rhône Fan, huge turbidite sedimentation occurred during the Pleistocene and led to aggradation and progradation of thick turbidite systems (up to 1300 m thick) linked to the main canyons or convergent system of canyons on the Gulf of Lions margin.

From indirect estimation, the building of the southern part of the upper complex of the Petit-Rhône Fan ended around 20 ka B.P., in response to instability of the levees and the lower continental slope inducing mass-transport events that probably were of short duration. During this episode of instability, collapse of the levees inside the main channel blocked the channel and induced its avulsion. Renewed aggrading activity occurred leading to the construction of the small channel/levee system of the Neofan on top of its avulsion lobe. The starvation of the Neofan probably relates to the progressive disconnection of the Rhône River and Petit-Rhône Canyon as the sea level was rising following the Last Glacial Maximum (MIS 2), and the definitive abandonment of the fan occurred 4 ka later upstream from the bifurcation point.

Distal turbidites accumulated in the Balearic Basin as a 9 m thick megaturbidite bed between 20.3 and 17.6 ka B.P., approximately at the time when the architecture and evolution of the Rhône Fan was strongly modified by instability processes that resulted in the shift of depocenters toward the Neofan. However, because of uncertainties about the age of these events, there is no clear relationship between the accumulation of the megaturbidite and either the mass-transport processes or the turbidite processes.

ka B.P. to present

During the deglacial period, the turbidite activity progressively diminished as sea-level rose. Definitive abandonment of the Rhône Fan occurred at 11 ka B. P. However, erosional activity remained in some canyons, until 8 ka B.P. (Sète Canyon) and 4 ka B.P. (La Fonera Canyon) [START_REF] Droz | Recent sedimentary events in the western Gulf of Lions (Western Mediterranean)[END_REF] and resulted in the re-deposition of eroded sediments as very thin unchannelized lobes at the outlet of the canyons. In addition, new hydrodynamic data obtained in the framework of the EUROSTRATAFORM programme show that some canyons of the Gulf of Lions (Cap de Creus, Lacaze-Duthiers and Petit-Rhône Canyons) are presently registering strong currents (e.g. [START_REF] Fabres | The impact of the December 2003 catastrophic storm on near bottom particle fluxes at canyon heads in the Gulf of Lions[END_REF].

V-Conclusions

Thanks to numerous results obtained over the last 20 years of research in the Gulf of Lions and northern Western Mediterranean, the Plio-Quaternary sedimentary evolution of the southern margin of France is now among the best known in the world. However, our knowledge of this margin is still lacking a good chronostratigraphy to constrain the general evolution and to precisely determine the main factors that controlled sedimentation during the Quaternary.

New data from the PROMESS 1 drilling cruise (june 2004(june : Berné 2004) ) will bring some of that stratigraphic constraints for the last 500 ka (Upper Quaternary) on the outer shelf and upper slope. Despite mass-movements that affect most of the continental slope, it is hoped to utilize high-resolution multi-channel seismic profiles across the margin to tie in the precise chronostratigraphic framework of Promess 1 to the turbiditic depositional sequences along the continental rise. [START_REF] Ryan | Initial Reports of the Deep-Sea Drilling Project[END_REF], white dots: Calypso cores in the Balearic Basin [START_REF] Rothwell | Low sea-level emplacement of a very large Late Pleistocene "megaturbidite" in the western Mediterranean Sea[END_REF]. Bathymetric data from [START_REF] Smith | Global sea floor topography from satellite altimetry and ship depth soundings[END_REF], Topography from GTOPO30 (U.S. Geological Survey's EROS Data). Realization M. Rabineau (UBO) and D. Aslanian IFREMER Brest. France, via the Rhône River that brings Alpine continental inputs to the Gulf of Lions, and the smaller Pyreneo-Languedocian Rivers that mainly drain the Pyrenees. The principal turbidite system is the Petit-Rhône Fan that extends basinwards up to the northern limit of the Balearic Basin. Synthesis mainly based on [START_REF] Droz | Rhône deep-sea fan: morphostructure and growth pattern[END_REF], dos [START_REF] Reis | La tectonique salifère et son influence sur l'architecture sédimentaire quaternaire de la marge du Golfe du Lion -Méditerranée Occidentale[END_REF], dos [START_REF] Reis | Implications of salt-sediment interactions on the architecture of the Gulf of Lions deep-water sedimentary systems -Western Mediterranean Sea[END_REF] for the Gulf of Lions turbidite systems; [START_REF] Droz | Recent sedimentary events in the western Gulf of Lions (Western Mediterranean)[END_REF][START_REF] Droz | Interrelationships between the sedimentary systems in the Western Mediterranean (Gulf of Lions and Balearic Abyssal Plain): preliminary results from PROGRES cruise (EUROSTRATAFORM programme)[END_REF][START_REF] Droz | The southern prolongation of the Rhône Neofan from recent high-resolution data[END_REF] and [START_REF] Bonnel | Architecture and depositional pattern of the Rhône Néofan and recent gravity activity in the Gulf of Lions (Western Mediterranean)[END_REF] for the Neofan and recent Sète and La Fonera sandy lobes; Palanques et al. (1994) for the Valencia Fan. Conchon 1992, (l): e.g. [START_REF] Gautier | Age et durée de la crise de salinité messinienne[END_REF][START_REF] Krijgsman | Chronology, causes and progression of the Messinian salinity crisis[END_REF]

  ; dos Reis 2001; dos Reis et al. 2005) face the main rivers outlets of the French Mediterranean margin.

Fig. 1 :

 1 Fig. 1: Bathymetry of the Western Mediterranean(contour isolines: 150, 300, 500, 1000, 1500, 2000, 2500 and 2800 m) and topography of surrounding lands. The square indicates the location of the synthetic map shown in figure3. Arrows: origin of inputs to the Balearic and Balearo-Provençal Basins (PL Rivers: Pyreneo-Languedocian rivers). Black dots: Industrial boreholes (including GLP1 mentioned in text), white squares: drilling sites of ODP Leg 13[START_REF] Ryan | Initial Reports of the Deep-Sea Drilling Project[END_REF], white dots: Calypso cores in the Balearic Basin[START_REF] Rothwell | Low sea-level emplacement of a very large Late Pleistocene "megaturbidite" in the western Mediterranean Sea[END_REF]. Bathymetric data from[START_REF] Smith | Global sea floor topography from satellite altimetry and ship depth soundings[END_REF], Topography from GTOPO30 (U.S. Geological Survey's EROS Data). Realization M. Rabineau (UBO) and D. Aslanian IFREMER Brest.

Fig. 2 :

 2 Fig. 2: Thickness of Quaternary sediments on the slope and rise of the Gulf of Lions. Slightly modified from dos Reis et al. (2005).

Fig. 3 :

 3 Fig.3: Synthetic map showing the main sedimentary systems in the northern Balearic Basin and western Balearo-Provençal Basin. Most of the sediments originate from the southern margin of France, via the Rhône River that brings Alpine continental inputs to the Gulf of Lions, and the smaller Pyreneo-Languedocian Rivers that mainly drain the Pyrenees. The principal turbidite system is the Petit-Rhône Fan that extends basinwards up to the northern limit of the Balearic Basin. Synthesis mainly based on[START_REF] Droz | Rhône deep-sea fan: morphostructure and growth pattern[END_REF], dos[START_REF] Reis | La tectonique salifère et son influence sur l'architecture sédimentaire quaternaire de la marge du Golfe du Lion -Méditerranée Occidentale[END_REF], dos[START_REF] Reis | Implications of salt-sediment interactions on the architecture of the Gulf of Lions deep-water sedimentary systems -Western Mediterranean Sea[END_REF] for the Gulf of Lions turbidite systems;[START_REF] Droz | Recent sedimentary events in the western Gulf of Lions (Western Mediterranean)[END_REF][START_REF] Droz | Interrelationships between the sedimentary systems in the Western Mediterranean (Gulf of Lions and Balearic Abyssal Plain): preliminary results from PROGRES cruise (EUROSTRATAFORM programme)[END_REF][START_REF] Droz | The southern prolongation of the Rhône Neofan from recent high-resolution data[END_REF] and[START_REF] Bonnel | Architecture and depositional pattern of the Rhône Néofan and recent gravity activity in the Gulf of Lions (Western Mediterranean)[END_REF] for the Neofan and recent Sète and La Fonera sandy lobes;Palanques et al. (1994) for the Valencia Fan.

Fig. 4 :

 4 Fig. 4: Schematic cross section on the rise of the Gulf of Lions (see figure 3 for approximate location), showing the Plio-Quaternary sedimentary architecture of the margin and stacking pattern of the turbidite systems and mass-transport deposits. Ages are inferred from industrial boreholes (GLP1, courtesy of Total, in Droz 1991 and dos Reis 2001). Redrawn and modified from dos Reis et al. (2005) to illustrate the mass transport deposits and the most recent sedimentary events (Neofan and Sète and La Fonera sandy lobes). Not to scale.

Fig. 5 :

 5 Fig. 5: Synthesis of the ages known from coring or inferred from correlations for the main sedimentary systems of the Northern Balearic Basin. References for age attribution: (a): Bonnel et al. 2005, (b): Lastras et al. 2002, 2004, (c): Méar 1, (d): Hoogakker et al. 2004, (e): proposed in this study, (f): Méar 1984, (g): Bellaiche et al. 1989, (h): e.g. Van Eysinga and Haq 1987, Kukla and Cilek 1996, (i): e.g. Ruddiman et al. 1986, Paillard 2001, (j): GLP1 borehole in Droz 1991 and dos Reis et al. 2005, (k): e.g. Conchon 1992, (l): e.g.[START_REF] Gautier | Age et durée de la crise de salinité messinienne[END_REF][START_REF] Krijgsman | Chronology, causes and progression of the Messinian salinity crisis[END_REF]