Vanessa Dyja
email: vanessa.dyja@univ-lorraine.fr

Christian Hibsch

Alexandre Tarantola

Michel Cathelineau

Marie-Christine Boiron

Christian Marignac

Daniele Bartier

Javier Carrillo-Rosúa

Salvador Morales

Philippe Boulvais

Christine Boiron

Danièle Bartier

Morales Ruano

From deep to shallow fluid reservoirs: evolution of fluid sources during exhumation of the Sierra Almagrera, Betic Cordillera, Spain

Keywords: Metamorphic Core Complex, Metamorphic brines, Fluid inclusions, Stable isotopes, Betic Cordillera, Trans-alboran fault Geofluids Metamorphic Core Complex / Metamorphic brines / Fluid inclusions / Stable isotopes / Betic 21 Cordillera

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During exhumation, synsedimentary transcurrent tectonic processes occurred from Late 37 Tortonian times onwards, while marine conditions prevailed at the Earth's surface. At depth in the 38 brittle domain, quartz veins associated with hematite record a return to high-salinity fluid 39 circulation suggesting an upward transfer fed from the lower reservoir. During the Messinian, 40 ongoing activity of the Trans-Alboran tectono-volcanic trend led to the formation of ore deposits. 41

Reducing fluids led to the formation of siderite and pyrite ores. The subsequent formation of 42 galena and barite may be related to an increase of temperature. The high salinity and Cl/Br ratio of 43 the fluids suggest another source of secondary brine derived from dissolved Messinian evaporites, 44 as corroborated by the δ 34 S signature of barite. This constrains the age of the mineralizing event at

Introduction 47

Fluids are vectors of heat and solute species. Migration of fluids is linked to local and 48 regional geology, and permeability is a key factor in controlling fluid flow (Manning & Ingebritsen, 49 1999[START_REF] Ingebritsen | Diffuse fluid flux through orogenic belts: Implications 1038 for the world ocean[END_REF]. Permeability is a function of time, heterogeneity-anisotropy 50 and scale [START_REF] Manning | Permeability of the continental crust: The implications 1083 of geothermal data and metamorphic systems[END_REF]. The Sierra Almagrera (southern Spain) is a favourable 51 terrain to evaluate the conditions of fluids migration within the Earth's lithosphere. Because this 52 The Betic Cordillera results from the convergence between the Africa and Eurasia plates 110 since the Eocene, and forms an alpine tectonic wedge reaching a thickness of about 60 km (Platt & 111 Vissers, 1989[START_REF] Lonergan | Origin of the Betic-Rif mountain belt[END_REF][START_REF] Platt | From orogenic hinterlands to Mediterranean-style back-arc basins: a comparative 1138 analysis[END_REF][START_REF] Jolivet | Subduction, convergence and the mode of backarc extension in the 1051 Mediterranean region[END_REF]. The internal Alboran 112 domain can be divided into three main tectono-metamorphic nappes, from bottom to top (Figure 1): 113 (i) the Nevado-Filábride nappe, itself divided into three sub-units from bottom to top: Ragua (not 114 represented on Figure 1, to the W), Calar-Alto and Bedar-Macael [START_REF] De | Tectono-metamorphic studies and radiometric dating in the Betic Cordilleras 955[END_REF], Martínez-115 Martínez et al., 2002), (ii) the Alpujarride nappe, and (iii) the Malaguide nappes (Egeler & Simon, 116 1969). In addition to isostatic uplift, these units were also exhumed due to tectonic unroofing 117 [START_REF] Lonergan | Evidence for Internal Zone unroofing from 1077 foreland basin sediments, Betic Cordillera, SE Spain[END_REF]. The associated WSW-ENE-striking tectonic extension 118 related to exhumation of the metamorphic continental crust is supposed to have resulted from partial 119 or complete removal of the lithospheric mantle [START_REF] Platt | Extensional collapse of thickened continental lithosphere: A 1143 working hypothesis for the Alboran Sea and Gibraltar arc[END_REF]. Arguments have also been 120 put forward for other mechanisms, such as subduction zone rollback [START_REF] Lonergan | Origin of the Betic-Rif mountain belt[END_REF], 121 Bezada et al., 2013). The contacts observed between structural units exhibiting different degrees of 122 metamorphism are attributed to major detachment faults (Figure 1-a): (1) The Alpujarride contact: unmetamorphosed Malaguide lithologies overlie the medium-pressure 124 medium-temperature metamorphic rocks of the Alpujarride nappe (Sierra Estancias, Figure 1-a), (2) 125

The Filabres major detachment: higher grade Nevado-Filábride metamorphic rocks, which were 126 exhumed during the Miocene, lie beneath the Alpujarride nappes. Ductile shearing related to this 127 exhumation affected the footwall and currently shows a transport direction top towards WSW to 128 SW [START_REF] Crespo-Blanc | Extension versus compression during the 952 Miocene tectonic evolution of the Betic chain. Late folding of normal fault systems[END_REF][START_REF] Martínez-Martínez | Orthogonal extension in the hinterland of the 1090 Gibraltar Arc (Betics, SE Spain), in Reconstruction of the evolution of the Alpine-1091 Himalayan Orogen[END_REF][START_REF] Platt | From orogenic hinterlands to Mediterranean-style back-arc basins: a comparative 1138 analysis[END_REF]. According to the 129 extensional tectonics expressed in the ductile fabrics, the metamorphic nappes reached the brittle 130 D r a f t C o p y domain during the ongoing exhumation. From the late Miocene, exhumation was mainly the result 131 of erosion since both the metamorphic cores and the sedimentary cover were affected by regional 132 compressional and local transcurrent tectonics. The Trans-Alboran transcurrent fault system 133 generated domains with both releasing and restraining deformation, which created juxtaposed zones 134 with opposite vertical motions (subsidence and uplift). The ranges (sierras) were separated by 135 basins either filled by continental or marine sediments according to time and location. This major 136 tectono-volcanic trend can be followed off-shore to the other side of the Mediterranean in Morocco 137 [START_REF] Hernandez | Le magmatisme neogene betico-1030 rifain et le couloir de decrochement trans-Alboran[END_REF]. 138

The volcanism linked to lithospheric thinning shows a gradual transition and great 139 geochemical diversity. The age of this volcanism varies from 34 Ma (tholeiitic dykes in Malaga 140 province) to 2 Ma (alkali basalts in Murcia province). There is a gap between the oldest volcanic 141 events in Malaga and the main magmatic activity in SE Spain and the Alboran Basin, which took 142 place between 12.6 and 7.5 Ma with tholeiitic and calc-alkaline affinities [START_REF] Bellon | Chronologie du magmatisme néogène des Cordillères 876 bétiques (Espagne méridionale)[END_REF]. Very 143 locally in the Sierra Cabrera, Miocene plutonism is recorded related to the retrograde 144 metamorphism and associated ductile deformation [START_REF] Westra | Petrogenesis of a composite metamorphic facies series in an intricate fault zone 1192 of the southeastern Sierra Cabrera (SE, Spain)[END_REF][START_REF] Bolze | Processus thermo-900 mécaniques associés à l'évolution des bassins néogènes des Bétiques internes orientales 901 (Espagne Sud-Est)[END_REF]. Since the 145 reappearance of volcanism during the Serravalian, other episodes of magmatic activity occurred 146 inland in SE Spain mainly between 10 and 6.2 Ma, showing high-K calc-alkaline, shoshonitic and 147 ultrapotassic affinities [START_REF] Bellon | Chronologie du magmatisme néogène des Cordillères 876 bétiques (Espagne méridionale)[END_REF][START_REF] Turner | 1176 Magmatism Associated with Orogenic Collapse of the Betic Alboran Domain, SE Spain[END_REF][START_REF] Zeck | Revised geochronology of the Neogene calc-1198 alkaline volcanic suite in Sierra de Gata, Alborán volcanic province, SE Spain[END_REF], Duggen et al., 148 2004[START_REF] Duggen | Post-Collisional 970 Transition from Subduction-to Intraplate-type Magmatism in the Westernmost 971 Mediterranean: Evidence for Continental-Edge Delamination of Subcontinental Lithosphere[END_REF][START_REF] Cesare | Do extrusion ages reflect magma generation 933 processes at depth? An example from the Neogene Volcanic Province of SE Spain[END_REF]. Heterogeneous sources and various processes are 149 implied in the magma genesis, including: (i) various degrees of partial melting, (ii) metasomatism 150 (i.e. oceanic and continental crust, sediments), (iii) anatexis of crustal metasedimentary basement 151 [START_REF] Benito | 878 Sr and O isotope constraints on source and crustal contamination in the high-K calc-alkaline 879 and shoshonitic neogene volcanic rocks of SE Spain[END_REF][START_REF] Duggen | Magmatic evolution of the 974 Alboran region: The role of subduction in forming the western Mediterranean and causing 975 the Messinian Salinity Crisis[END_REF][START_REF] Duggen | Post-Collisional 970 Transition from Subduction-to Intraplate-type Magmatism in the Westernmost 971 Mediterranean: Evidence for Continental-Edge Delamination of Subcontinental Lithosphere[END_REF][START_REF] Prelevic | Mediterranean Tertiary lamproites 1145 derived from multiple source components in postcollisional geodynamics[END_REF], Álvarez-Valero 152 & Kriegsman, 2008[START_REF] Conticelli | Trace elements and Sr-Nd-Pb isotopes of 948 K-rich, shoshonitic, and calc-alkaline magmatism of the Western Mediterranean Region: 949 Genesis of ultrapotassic to calc-alkaline magmatic associations in a post-collisional 950 geodynamic setting[END_REF]. 153

The Neogene evolution of the Betics is associated with a series of base and precious metal-154 bearing hydrothermal ore systems developed mainly in the calc-alkaline volcanic rocks of the Cabo 155 de Gata range, but also in sedimentary and metamorphic basement lithologies (Figure 1). 156

D r a f t C o p y
Epithermal ore deposits are hosted by intermediate to acid volcanics ranging in age from 12 to 10 157 Ma; these deposits are found in a number of different mining districts, for example, Zn-Pb-Cu(-Ag-158 Au) at San José [START_REF] Demoustier | Clasificación textural del cuarzo epitermal 959 (Au-Ag) de relleno filoniano del área volcánica de Cabo de Gata, Almería[END_REF][START_REF] Esteban-Arispe | Mineralogy and fluid evolution of Pb-Zn-Cu(Ag-Au) epithermal veins in San José (Almería, 985 Southeastern Spain)[END_REF], Au(-Cu-Te-Sn) at 159 Rodalquilar [START_REF] Arribas | Geology, geochronology, fluid inclusions, and isotope 836 geochemistry of the Rodalquilar gold alunite deposit, Spain[END_REF] and Cu-Au-Ag at Carboneras [START_REF] Morales Ruano | 1120 Epithermal Cu-Au mineralization in the Palai-Islica deposit, Almeria, southeastern Spain: 1121 Fluid-inclusion evidence for mixing of fluids as a guide to gold mineralization[END_REF], 160 Carrillo-Rosúa et al., 2009). Ba-Ag mineralizations are found in sedimentary rocks, close to high-K 161 calc-alkaline and shoshonitic volcanics within the Vera Basin [START_REF] Alvado | Sédimentation, déformation et manifestation magmatiques associées au 828 couloir de décrochement de Palomares : le bassin de Vera (SE de l'Espagne)[END_REF], Martínez-Frías, 162 1998). Certain ore deposits are hosted by metamorphic rocks, including the occurences of Pb-Zn-163

Fe-Cu (Al) at Cartagena [START_REF] Graeser | Zur Frage der Alterstellung und Genese der Blei-Zink-1025 Vorkommen der Sierra de Cartagena in Spanien[END_REF][START_REF] Oen | The lead-zinc and associated ores of La Union-1128 Sierra de Cartagena, Spain[END_REF][START_REF] Arribas | Distribucion de elementos en trazas en las esfaleritas 839 y galenas de las mineralizaclones espanolas asociadas con rocas volcanicas[END_REF] and Zn-Ag-Fe at Sierra Almagrera and Sierra Aguilon [START_REF] Martinez Frias | 1096 Las mineralizaciones epitermales de Sierra Almagrera y de la cuenca de Herrerías, 1097 Cordilleras Béticas[END_REF], Morales Ruano et 165 al., 1993). Samples from the Sierra Almagrera mining distict allow us to reconstruct the fluid 166 history described below. 167

Geology of the Sierra Almagrera (Figure 1-b) 168

The metamorphic range of the Sierra Almagrera exposes a Nevado Filabres unit largely 169 composed of graphitic quartz-rich chloritoid-schists [START_REF] Booth-Rea | Influence of strike-slip fault 903 segmentation on drainage evolution and topography. A case study: the Palomares Fault 904 Zone (southeastern Betics, Spain)[END_REF] and quartzites. 170

Locally, carbonates and gypsum are found north of the Sierra Almagrera within an Alpujarride unit 171 [START_REF] Álvarez | Las unidades de la zona Bética en la región de Águilas-Mazarrón 833 (Prov. de Murcia)[END_REF]. The present-day geomorphology of the Sierra Almagrera mainly results 172 from sinistral strike-slip faulting in the area that generated several fault segments at various scales. 173

The Palomares Fault Zone results in an approximately 16 km North-South trending left-lateral 174 relative displacement [START_REF] Booth-Rea | Influence of strike-slip fault 903 segmentation on drainage evolution and topography. A case study: the Palomares Fault 904 Zone (southeastern Betics, Spain)[END_REF]. This transcurrent faulting may have started during 175 the late Tortonian (around 7.2 Ma), but was mainly active during the Messinian. The evolution of 176 this faulting associated with a vertical component (oblique faulting) caused the recent uplift, thus 177 leading to erosion and exhumation of the Sierra Almagrera during the Plio-Quaternary. The 178 southern segments of the Palomares Fault Zone dip towards the West. Their transtensional activity 179 favoured the subsidence of the western block. By contrast, the northern segments, which are 180 dipping towards the ESE, are related to a sinistral restraining bend that favoured the uplift of the 181 Sierra Almagrera mountain ranges located to the East of the zone [START_REF] Booth-Rea | Influence of strike-slip fault 903 segmentation on drainage evolution and topography. A case study: the Palomares Fault 904 Zone (southeastern Betics, Spain)[END_REF]. In the 182 D r a f t C o p y studied area, small bodies of high-K calc-alkaline to shoshonitic rhyodacites (Lopez Ruiz & 183 Rodriguez Badiola, 1980[START_REF] Benito | 878 Sr and O isotope constraints on source and crustal contamination in the high-K calc-alkaline 879 and shoshonitic neogene volcanic rocks of SE Spain[END_REF] are encountered along the transcurrent fault system. 184

Regional ages determined on this volcanic suite are between 11.9 and 6.2 Ma [START_REF] Duggen | Magmatic evolution of the 974 Alboran region: The role of subduction in forming the western Mediterranean and causing 975 the Messinian Salinity Crisis[END_REF]. 185

Less abundant lamproites from the ultrapotassic series [START_REF] Lopez Ruiz | La region volcanica neogena del sureste de Espana[END_REF], 186 dated at between 8.4 and 6.4 Ma [START_REF] Prelevic | Mediterranean Tertiary lamproites 1145 derived from multiple source components in postcollisional geodynamics[END_REF], crop out within the Vera basin to the south 187 of Sierra Almagrera (Figure 1 The area located within the Palomares Fault Zone (hanging-wall) is referred to here as "the 198 subsident area". Locally, mineralizations can be found within the Messinian sediments (Las 199 Herrerias). The ore consists of barite veins, with native Ag and base-metal sulphides in very small 200 amounts [START_REF] Alvado | Sédimentation, déformation et manifestation magmatiques associées au 828 couloir de décrochement de Palomares : le bassin de Vera (SE de l'Espagne)[END_REF][START_REF] Martínez-Frías | An ancient Ba-Sb-Ag-Fe-Hg-bearing hydrothermal system in SE Spain[END_REF][START_REF] Carrillo-Rosúa | The three generations of gold 927 in the Palai-Islica epithermal deposit, southeastern Spain[END_REF], 2003). 201 inclusion planes are found within single grains in microcracks that do not cross-cut grain boundaries 209 [START_REF] Van Den Kerkhof | Fluid inclusion petrography[END_REF]. Transgranular fluid inclusion planes result from healing of 210 former open cracks [START_REF] Krantz | Microcracks in rocks: a review[END_REF][START_REF] Boullier | Fluid inclusions: tectonic indicators[END_REF][START_REF] Lespinasse | Are fluid inclusion planes useful in structural geology?[END_REF][START_REF] Lespinasse | Microfissural mapping of natural 1071 cracks in rocks: Implications for fluid transfers quantification in the crust[END_REF] as 211 rocks undergo brittle deformation. Systematic measurements of the fluid inclusion planes were 212 carried out on each section using an ANIMA interactive videographic image analyzer (Lespinasse 213 et al., 2005). The plunge and dip directions of the fluid inclusion planes are represented on equal-214 area lower-hemisphere stereograms using Stereonet® software. 215

Methods

Microthermometry 216

The phase transitions of the fluid inclusions were characterised between -170 °C and +600 °C 217 using a LINKAM MDS 600 heating-freezing stage mounted on an Olympus microscope, calibrated 218 using CO 2 and H 2 O synthetic and natural alpine fluid inclusions. The accuracy of measurements 219 varies from ±0.2 °C at low temperature (experiments at 0.5-1 °C/min) to ±2 °C at high temperature 220 (experiments at 1-5 °C/min). Table 1 reports the abbreviations of terms and the phase transition 221 temperatures observed during microthermometric experiments. For barite and calcite, the high-222 temperature transitions were studied first to prevent leakage of fluid inclusions during ice formation 223 on cooling. Photographs of fluid inclusions after each measurement were compared with the 224 original picture to evaluate any leakage. 225

Raman microspectroscopy 226

Raman analysis of fluid inclusions was performed with a LabRAM microspectrometer 227 (Horiba Jobin Yvon, at GeoRessources, Vandoeuvre-lès-Nancy, France) equipped with a 1800 228 gr.mm -1 grating and a ×80 Olympus objective. The exciting radiation was provided by the 514.5 nm 229 line of an Ar + laser (Stabilite 2017, Newport Corp., Spectra Physics) at a power of 400 mW. The 230 signal-to-noise ratio was optimized by adjusting acquisition time and accumulation number. The 231 quantitative analysis of the gas phase was performed using a specific calibration of the laboratory. 232

Results are given as mol% relative to the volatile phase. 233 D r a f t C o p y

P-V-T-X calculation of fluid inclusions 234

In this study, we use microthermometric data associated with mole fractions of the different 235 gas species obtained by Raman spectroscopy to reconstruct the P-V-T-X evolution of fluid 236 inclusions. The salinities of aqueous fluid are calculated using the final melting temperature of ice 237 when gases are not present in sufficient amounts to form gas hydrates [START_REF] Bodnar | Introduction to aqueous-electrolyte fluid inclusions[END_REF]. In this case, 238 the isochore is a function of the homogenization temperature at a given salinity, and the empirical 239 equation of state of [START_REF] Zhang | Determination of the homogenization temperatures and 1201 densities of supercritical fluids in the system NaClKClCaCl2H2O using synthetic fluid 1202 inclusions[END_REF] is used within a P-T domain of validity of T: 180-700 240 °C and P: 0.1-300 MPa. 241

The salinities of aqueous carbonic fluids and molar volumes (V m ) of the volatile phase are 242 calculated using the program ICE and the dissociation temperature of clathrate [START_REF] Bakker | Clathrates: Computer programs to calculate fluid inclusion V-X properties 857 using clathrate melting temperatures[END_REF](Bakker, , 243 2003) ) when gases are present in significant amounts to allow the formation of gas hydrates. The 244 isochores are calculated using the program ISOC [START_REF] Bakker | Clathrates: Computer programs to calculate fluid inclusion V-X properties 857 using clathrate melting temperatures[END_REF][START_REF] Bakker | Package FLUIDS 1. Computer programs for analysis of fluid inclusion data 861 and for modelling bulk fluid properties[END_REF] and the equation of state 245 [START_REF] Bowers | Calculation of the thermodynamic and geochemical 916 consequences of nonideal mixing in the system H2O-CO2-NaCl on phase relations in 917 geologic systems: Equation of state for H2O-CO2-NaCl fluids at high pressures and 918 temperatures[END_REF] revised by [START_REF] Bakker | Adaptation of the Bowers and Helgeson (1983) equation of state to the H2O-859 CO2-CH4-N2-NaCl system[END_REF] for the system H 2 O-CO 2 -CH 4 -N 2 -NaCl, with 246 a P-T domain of validity of T: 350-600 °C and P: 50-200 MPa. 247

Crush-leach analysis for halogen chemistry 248

Because the halogens display a conservative behaviour in solution, and remain relatively 249 unaffected by fluid-rock interactions [START_REF] Banks | The chemistry 868 of brines from an Alpine thrust system in the Central Pyrenees: An application of fluid 869 inclusion analysis to the study of fluid behaviour in orogenesis[END_REF], the signature of the elements Cl and Br in 250 a fluid can be used to characterize its source [START_REF] Böhlke | Laser microprobe analyses of noble gas isotopes and halogens in 894 fluid inclusions: Analyses of microstandards and synthetic inclusions in quartz[END_REF]. 251 Bulk crush-leach analyses were performed to extract and analyse fluids hosted in quartz, 252 barite and siderite. Samples were prepared according to the methodology of [START_REF] Bottrell | A modified crush-leach method for the 909 analysis of fluid inclusion electrolytes[END_REF]. 253

The amount of sample crushed was between 0.5 and 1.0 g. Analysis of the anions F, Cl, Br, I and 254 SO 4 was performed by ion chromatography using a ICS 3000 Dionex system with a AS20 column 255 at the LIEC laboratory (Nancy, France). Br was also analysed by LA-ICPMS in a series of 256 representative fluid inclusions using the procedure described by Leisen et al. (2012a). 257 (200 pulses at 5 Hz). The design as an optical imaging system allows the use of different crater 267 diameters (24, 32 or 60 µm) at constant energy density on the sample, by adjusting an aperture in 268 the laser beam path. Na, K, Mg, Ba, Sr, Mn, Li, Fe, Cu and Zn are analysed here. Concentrations 269 are calculated according to [START_REF] Leisen | Improvement of the determination of 1065 element concentrations in quartz-hosted fluid inclusions by LA-ICP-MS and Pitzer 1066 thermodynamic modeling of ice melting temperature[END_REF]. 270

Laser Ablation ICP-MS 258

Raman spectroscopy of carbonaceous materials 271

The Raman Spectrum of Carbonaceous Material (RSCM) has been calibrated as a 272 geothermometer in the range 330-640 °C [START_REF] Beyssac | Raman spectra of carbonaceous material 884 in metasediments: A new geothermometer[END_REF][START_REF] Beyssac | Thermal metamorphism in the lesser 881 Himalaya of Nepal determined from Raman spectroscopy of carbonaceous material[END_REF]). The RSCM displays one 273 graphite band (G band) and several defect-activated bands (D1 and D2 bands) between 1100 and 274 1800 cm -1 [START_REF] Beyssac | Application of Raman spectroscopy to the study of graphitic 886 carbons in the Earth Sciences[END_REF], whose intensities decrease with increasing metamorphic 275 grade. Raman analysis of graphite-bearing schists was performed on thin sections oriented 276 perpendicular to the foliation and parallel to the lineation by focusing the laser beam beneath a 277 transparent crystal to avoid the effect of amorphization due to polishing. The Raman spectrometer 278 used in this study is a LabRAM HR instrument (Horiba Jobin Yvon) (GeoRessources, Vandoeuvre-279 lès-Nancy, France) equipped with a 600 gr.mm -1 grating and a ×100 objective (Olympus). The 280 excitation beam is provided by an Ar + laser (Stabilite 2017, Newport Corp., Spectra Physics) at 281 457.9 nm. Laser power is reduced to avoid heating the samples, using optical filters of various 282 optical densities, and was always lower than 5 mW. The acquisition time is 15 seconds, with each 283 measurement repeated 6 times. 10 to 15 spectra are recorded for each sample for statistical 284 D r a f t C o p y purposes. Peak fitting is performed using the Peak Analyser of the OriginPro 8.5.1 software. The 285 following expression [START_REF] Beyssac | Raman spectra of carbonaceous material 884 in metasediments: A new geothermometer[END_REF] is used to derive peak temperature conditions: T(°C)= -286 445R2 + 641, with R2 (peak area ratio) = (D1/(G+D1+D2)). 287

Stable isotopes 288

δ 18 O and δ 13 C of siderite 289

15 to 20 mg of siderite were reacted at 70 °C with H 3 PO 4 for 15 days (Scheppard & 290 Schwarcz, 1970). Isotopic ratios were measured using a modified VG 602D mass spectrometer at 291 the CRPG laboratory (Vandoeuvre-lès-Nancy, France), and the results are reported using 292 conventional δ 18 O (V-SMOW) and δ 13 C (V-PDB) notations. The analytical reproducibility is ±0.1 293 ‰ for δ 18 O and δ 13 C. 294

δ 18 O of quartz 295

6.5 to 7.5 mg of quartz (same grains as those used for fluid inclusion analyses) were analysed 296 using the conventional fluorination method [START_REF] Clayton | The use of bromine pentafluoride in the extraction of 944 oxygen from oxides and silicates for isotopic analysis[END_REF]. The measurements were 297 carried out with a VG SIRA 10 triple-collector instrument at the University of Rennes 1 (France). 298

The analytical reproducibility (estimated from duplicates performed on different Ni fluorination 299 tubes) is ±0.2‰. 300

δ 34 S of sulphides and sulphates 301

Sulphur isotope compositions were measured following the method of Giesemann et al. 302 (1994) at the CRPG laboratory (Vandoeuvre-lès-Nancy, France) by EA-IRMS (Elemental Analyser-303 Isotopic Ratio Mass Spectrometer). δ 34 S was measured with a GV Instruments Isoprime mass 304 spectrometer coupled in continuous-flow mode to a EuroVector elemental analyser. Results are 305 reported using conventional δ 34 S (CDT). No inter-sample memory effect was observed. Linearity of 306 the mass spectrometer and reproducibility of the analysis were checked using CRPG internal 307 reference materials. The analytical reproducibility obtained on the barium sulphate reference 308 material used at CRPG is lower than 0.3 ‰. 309 D r a f t C o p y

δD of white micas 310

2 to 3 mg of powdered host-rock were analysed for the isotopic composition of hydrogen-311 bearing minerals, mainly phengite. δD was measured with a GV Instruments Isoprime mass 312 spectrometer coupled in continuous-flow mode to a EuroVector elemental analyser. No inter-313 sample memory effect can be observed. Linearity of the mass spectrometer and reproducibility of 314 the analysis were checked using CRPG internal reference materials with an analytical 315 reproducibility lower than 0.3‰. 316

δD of fluid inclusions 317

Fluids trapped in quartz, barite and siderite crystals were extracted for isotopic analyses by 318 crushing under vacuum. Aliquots of 1.0 to 5.1 g of mn-sized grains were loaded into steel tubes and 319 degassed overnight at 120 °C under vacuum to release any water adsorbed at the mineral surface 320 [START_REF] Dublyansky | Hydrogen and oxygen isotopes of water from inclusions in 967 minerals: design of a new crushing system and on-line continuous-flow isotope ratio mass 968 spectrometric analysis[END_REF]. Preliminary tests conducted under the microthermometric heating 321 stage showed no decrepitation or stretching of the studied fluid inclusions at temperatures below 322 200 °C. H 2 O was separated cryogenically from other gases and reduced to H 2 in a uranium reactor 323 at 800 °C. D/H ratio of H 2 was determined using a dual-inlet VG Micromass 602D mass 324 spectrometer at the CRPG laboratory (Vandoeuvre-lès-Nancy, France). External reproducibility of 325 D/H measurements was estimated to be lower than 3 ‰ by normalizing raw data to the V-SMOW-326 SLAP scale. Two CRPG water standards were analysed along with each weekly batch of water 327 samples obtained from the fluid inclusions. 328

To avoid any memory effect on D/H ratios within the uranium reactor, samples were 329 systematically duplicated. For each duplicate, δD values from the first extraction are discarded since 330 they could be affected by this memory effect. 331

For quartz containing primary inclusions, δ 18 O fluid was calculated from δ 18 O quartz using the 332 quartz-water fractionation equation of [START_REF] Zheng | Calculation of oxygen isotope fractionation in anhydrous silicate minerals[END_REF] All sampled veins are hosted in schists composed of phengite, quartz, graphite and rutile. 337

Although not observed in this study, biotite and garnet have also been described in these rocks 338 [START_REF] Álvarez | Las unidades de la zona Bética en la región de Águilas-Mazarrón 833 (Prov. de Murcia)[END_REF] as well as chloritoid [START_REF] Booth-Rea | Influence of strike-slip fault 903 segmentation on drainage evolution and topography. A case study: the Palomares Fault 904 Zone (southeastern Betics, Spain)[END_REF]. The strike of the foliation 339 on the western flank of Sierra Almagrera (the studied area) oscillates between N045E and N100E, 340 with an average dip of around 25-30ºSE-S that can reach up to 45ºSE-S at El Arteal mine (Figure 1-341 b). Although stretching lineation is not always observed, deformed quartz veins (V-Qtz1) indicate a 342 top to the West shearing (Figure 2-a). 343

The Raman study of graphitic carbon yields R2 ratios from 0.12 to 0.21 (mode: 0.18; n=8, in 344 3 samples), corresponding to temperatures ranging between 545 and 590 °C. These results are in 345 agreement with the temperatures of 535-550 °C determined using the same method in the Calar 346 Alto unit from the Sierra de Los Filabres [START_REF] Augier | 847 Exhumation constraints for the lower Nevado-Filabride Complex (Betic Cordillera, SE 848 Spain): a Raman thermometry and Tweequ multiequilibrium thermobarometry approach[END_REF]. Phengite shows Si contents ranging 347 from 3.31 to 3.05 a.p.f.u (n=4, in 2 samples), corresponding to an estimated pressure ranging from 348 2.2 kbar at 545 °C to 9.7 kbar at 590 °C [START_REF] Massonne | Phengite geobarometry based on the limiting assemblage 1099 with K-feldspar, phlogopite, and quartz[END_REF]. These pressures are similar 349 to those obtained in the Calar-Alto unit in the Sierra de Los Filabres (10±0.7 kbar to 3.1±0.3 kbar) 350 [START_REF] Augier | 847 Exhumation constraints for the lower Nevado-Filabride Complex (Betic Cordillera, SE 848 Spain): a Raman thermometry and Tweequ multiequilibrium thermobarometry approach[END_REF]. 351

Vein and fluid inclusion petrography 352

According to their geometry, petrography and position relative to the host rock foliation, five 353 types of veins can be defined (Table 2). Table 3 summarizes the characteristics of the fluid 354 inclusions observed within each vein. 355

V-Qtz1, quartz veins parallel to host-rock foliation 356

V-Qtz1 veins (thickness less than 30 cm) may be found in both structural blocks (Figure 2-a b) or lobate grain boundaries interpreted as due to grain boundary migration (Jessell, 360 1987[START_REF] Passchier | Microtectonics[END_REF][START_REF] Stipp | Dynamic recrystallization near the brittle-plastic transition in 1165 naturally and experimentally deformed quartz aggregates[END_REF] 3). 364

V-Qtz2, quartz veins parallel to or oblique to host-rock foliation 365

V-Qtz2 (thickness of about 10 cm) are oblique to the rock foliation along certain sections of 366 the vein, while other parts are parallel (Figure 3-a). Since V-Qtz2 partly crosscuts the rock foliation, 367 they are considered as postdating V-Qtz1, which is parallel to the foliation. V-Qtz2 are 368 characterized by anhedral quartz grains of about 3-5 mm, showing undulose extinction. These 369 grains are characterized by wave-shaped grain-boundaries and subgrain boundaries. Subgrain 370 rotation and bulging recrystallization processes can be distinguished (Figure 3

V-ore, oblique mineralised veins from the mining district 389

An extensive study of ore mineralogy in the mining district [START_REF] Morales Ruano | Mineralogia, geocuimica y metalogenia de los yacimientos 1112 hidrothermales del sureste de Espana (Aguilas-Sierra Almagrera[END_REF] shows the 390 occurrence of abundant siderite, barite, pyrite, marcasite, galena, chalcopyrite, sphalerite, 391 tetrahedrite-tennantite, veenite, gersdorffite and bournonite and trace amounts of pyrrothite, 392 bismuthinite, arsenopyrite and bravoite. Our sampled veins (V-ore) show only part of this 393 paragenesis. 394 V-ore veins crosscut V-Qtz1 (Figure 5-a), V-Qtz2 and V-Qtz3 (Figure 4-a). The thickness of 395 the sampled V-ore veins can reach several dm. They are distributed in two main clusters striking 396 N000-160E and N120-130E. Micro-euhedral quartz (0.5-1.0 mm) is observed on the walls of V-ore 397 (Figure 5-a) predating siderite formation. Pyrite is included in siderite (Figure 5-c). Galena occurs at 398 the contact between siderite and barite (Figure 5-b). The mineral sequence can be summarized as 399 follows: micro-euhedral quartz-siderite-pyrite-galena-barite (Figure 5-c). 400 Qtz-ore-tg inclusions are parallel to the wall rock and crosscut several micro-euhedral quartz 401 grains. Fluid inclusions in siderite and barite are observed along cleavage planes and interpreted as 402 primary (Figure 5-d-e). 403

V-Cal, oblique calcite veins from the subsident area 404

These lenticular tension gashes crosscut V-Qtz2 and attain a length of several cm with an 405 opening of a few mm (Figure 6-a). Fluid inclusions are found as clusters and are interpreted as 406 primary (Figure 6-b-c). 407

Microthermometry and Raman results 408

Table 3 presents 4 andFigure 7. Aqueous carbonic fluid inclusions are recorded in quartz veins 411 (Qtz1-tg1, tg2, Qtz2-ig, Qtz2-tg and Qtz3-tg), whereas aqueous fluid inclusions are recorded in ore 412 veins. 413

Fluid inclusions in Qtz1 414

The salinity of Qtz1-tg1 ranges between 9.7 and 22.6 mass% NaCl eq. , with T h (L) between 415 319 and 350 °C. The volatile phase is predominantly CO 2 (70-85 vol%), with minor amounts of 416 CH 4 (10-17 vol %) and N 2 (0-18 vol%). 417

The salinity of Qtz1-tg2 ranges between 21.6 and 23.8 mass% NaCl eq , with T h (L) between 418 305 and 344 °C. The volatile phase is predominantly CO 2 (89-97 vol %), with minor amounts of 419 CH 4 (0-8 vol%) and N 2 (0-7 vol%). 420

Fluid inclusions in Qtz2 421

The salinity of Qtz2-ig ranges between 11.9 and 20.6 mass% NaCl eq. , with T h (L) between 220 422 and 400 °C. This broad scatter of homogenization temperatures is attributed to volume modification 423 of fluid inclusions during high-temperature deformation [START_REF] Vityk | Natural and synthetic re-equilibration textures of fluid 1184 inclusions in quartz (Marmarosh Diamonds): Evidence for refillingunder conditions of 1185 compressive loading[END_REF][START_REF] Bodnar | Introduction to aqueous-electrolyte fluid inclusions[END_REF], 424 Diamond et al., 2010). Therefore, we only consider T h of intact inclusions with the smallest gas 425 bubbles (flw > 65 vol %), resulting in a range from 220 to 355 °C. The volatile phase is dominated 426 by CO 2 (87-98 vol %), with minor amounts of CH 4 (1-8 vol %) and N 2 (1-7 vol %). 427

The salinity of Qtz2-tg ranges between 0.1 and 2.4 mass% NaCl eq. , with T h (L) between 290 428 and 330 °C. Raman spectroscopy shows that the volatile phase is predominantly CO 2 (57-85 vol %), 429 with presence of CH 4 (5-30 vol %), N 2 (7-12 vol %) and H 2 S (1-5 vol %). 430

Fluid inclusions in Qtz3 431

The salinity of Qtz3-p ranges between 12.7 and 20.9 mass% NaCl eq. , with T h (L) between 235 432 and 310 °C. The volatile phase is predominantly CO 2 (91-99 vol %), with minor amounts of CH 4 (1-433 7 vol %) and N 2 (0-5 vol %). 434 The salinity of Qtz-ore-tg ranges between 18.4 and 25.0 mass% NaCl eq. . Methane (traces) is 437 the only volatile present. T h (L) ranges between 150 and 248 °C. 438

The salinity of Sd-p ranges between 15.4 and 24.6 mass% NaCl eq. . Because no hydrohalite 439 melting or clathrate dissociation temperature could be observed, our calculation is based on the final 440 ice melting only and does not take into account the complexity of the fluid system. Therefore, some 441 data yield salinity higher than halite saturation in the H 2 O-NaCl system. T h (L) is observed between 442 110 and 222 °C. Such a large variation is likely related to leakage within this highly cleavable 443 mineral [START_REF] Bodnar | Introduction to aqueous-electrolyte fluid inclusions[END_REF]. Raman spectroscopy shows that CH 4 is the only volatile in the gas phase. 444

The salinity of Brt-p ranges between 20.7 and 25.8 mass% NaCl eq. . Again, because 445 hydrohalite is never observed, our calculations only take account of T m (ice) and the complexity of 446 the system is not fully expressed. Therefore, some of our data show salinities higher than NaCl 447 saturation in the H 2 O-NaCl system. T h (L) is observed between 237 and 335 °C. Although the 448 inclusions were carefully checked before and after measurements, leakage before 449 microthermometric experiments cannot be excluded [START_REF] Ulrich | Systematics of stretching of fluid inclusions. II. Barite at one 1179 atmosphere confining pressure[END_REF][START_REF] Bodnar | Introduction to aqueous-electrolyte fluid inclusions[END_REF], so 450 these values in barite should be considered very carefully. Raman spectroscopy shows that the 451 volatile phase is predominantly composed of CO 2 (45-93 vol %) (although present in small amount) 452 and N 2 (5-52 vol %) with minor CH 4 (0-5 vol %). 453

Fluid inclusions in calcite from V-Cal 454

The salinity of Cal-p ranges between 11.8 and 18.4 mass% NaCl eq. , with T h (L) between 67 455 and 87 °C (Figure 7). Raman spectroscopy does not allow us to identify the nature of the gas phase. 456

Halogen chemistry 457

For V-Qtz1, a Cl/Br molar ratio of 1000 is obtained by crush-leach analysis and LA-ICPMS 458 for a chlorinity of 4200 mmol/kg solution (Figure 8). The crushing experiments release fluids 459 derived from Qtz1-tg1 and Qtz1-tg2 as well as the fluid contained at grain boundaries. 460

D r a f t C o p y
Sd-p and Brt-p yield a Cl/Br ratio of between 3 500 and 10 000 for a chlorinity between 4 200 461 and 5 400 mmol/kg solution, respectively. The Cl/Br ratio of Brt-p obtained with LA-ICP-MS is 462 between 1 200 and 4 500 (Figure 8). The other populations of fluid did not give an interpretable 463 signal. 464

Major and trace element chemistry 465

In both types of fluids (Qtz1-tg1 (n=8), Qtz2-tg (n=2), Qtz3-p (n=4) and Brt-p (n=9)) 466 inclusions major (Na, K, Mg) and trace elements (Li, Mn, Fe, Cu, Zn, Sr and Ba) have been 467 measured (Table 5, Figure 9). The other generations of fluids do not give any interpretable signals. 468

In Qtz1-tg1 high salinity fluid, Na content ranges from 27000 to 122 000 ppm, K from 2000 469 to 7600 ppm, yielding Na/K ratio ranging from 10 to 30. Mg content is relatively variable (100-470 1600ppm). Li content is relatively high (200 to 1000 ppm). Mn, Fe, Ba and Sr display noticeable 471 concentration (Table 5, Figure 9). 472

On the contrary, Qtz2-tg having very low salinity show lower cation content and Na/K ratio is 473 ranging from 1 to 6. Due to the low salinity fluid, few data could be obtained. Former trapped fluid inclusions appear to have been transported to the grain boundaries during 490 hydrolytic weakening (e.g. [START_REF] Kerrich | Some effects of tectonic recrystallisation on fluid inclusions in vein quartz[END_REF][START_REF] Wilkins | Fluid inclusions, deformation and recrystallization in 1194 granite tectonites[END_REF][START_REF] Johnson | Syndeformational fluid trapping in quartz: determining the 1046 pressure-temperature conditions of deformation from fluid inclusions and the formation of 1047 pure CO2 fluid inclusions during grain-boundary migration[END_REF], 491 Hollister, 1990[START_REF] Bakker | Preferential water leakage from fluid inclusions by means 863 of mobile dislocations[END_REF], 1994), so it is likely that remnants of this fluid were 492 measured. In the mining district, V-Qtz1 veins host Qtz1-tg1 and Qtz1-tg2 type inclusions. The 493 transgranular fluid inclusion planes show δD values between -28 and -32 ‰ V-SMOW , possibly 494 reflecting the influence of δD inherited from earlier fluids displaced to grain boundaries during 495 quartz recrystallization. 496 δD fluid from Qtz2-ig and Qtz3-p inclusions cover a similar range between -23 and -36 ‰ V- 497 SMOW (Table 6, Figure 10). δD fluid from Qtz2-tg (selected section with dominant Qtz2-tg inclusions 498 in the quartz grains) display a larger range of values between -17 and -48 ‰ V-SMOW (Table 6, 499

Figure 10). 500 V-ore veins are significantly more D-depleted. δD fluid of Sd-p range between -65 and -80 ‰ 501 V-SMOW. δD fluid of Brt-p ranges between -53 and -69 ‰ V-SMOW (Table 6, Figure 10). 502 is compatible with top-to-the-W / top-to-the-SW extensional shearing similar to that observed in the 506 Sierra de los Filabres [START_REF] Augier | Late Orogenic doming in the eastern Betic Cordilleras: 851 Final exhumation of the Nevado-Filabride complex and its relation to basin genesis[END_REF] (Figure 1). This deformation is not dated in the Sierra 507 Almagrera. The only known age constraint is given by the youngest ductile extensional stages 508 recognized within the Betics metamorphic pile, which are dated around the Langhian-Serravalian 509 boundary at 14 Ma [START_REF] Gomez-Pugnaire | A reinterpretation of the Nevado-Filabride and 1017 Alpujarride Complexes (Betic Cordillera): Field, petrography and U-Pb ages from 1018 orthogneisses (western Sierra Nevada, S Spain)[END_REF][START_REF] Platt | Early Miocene 1140 continental subduction and rapid exhumation in the western Mediterranean[END_REF][START_REF] Gomez-Pugnaire | Late Variscan 1022 magmatism in the Nevado-Filabride Complex: U-Pb geochronologic evidence for the pre-1023 Mesozoic nature of the deepest Betic complex (SE Spain)[END_REF]. 510

Discussion

Although no fluid inclusions are observed in V-Qtz1 veins sampled from the subsident area, 511 crushing techniques allowed us to extract a fluid, which could then be analysed for its δD. This 512 suggests that fluid inclusions trapped prior to plastic deformation are displaced towards grain 513 boundaries during recrystallization processes [START_REF] Kerrich | Some effects of tectonic recrystallisation on fluid inclusions in vein quartz[END_REF][START_REF] Wilkins | Fluid inclusions, deformation and recrystallization in 1194 granite tectonites[END_REF], Johnson & 514 Hollister, 1995) and are then partly preserved. The calculated equilibrium temperature between this 515 fluid and host-rock, based on hydrogen isotope fractionation, is comprised between 488 and 520 °C 516 (Table 6), which is in agreement with ductile conditions. Plastically deformed or dismembered 517 inclusions are found within intragranular planes of V-Qtz2 (Qtz2-ig), while non-deformed 518 inclusions are found within transgranular planes affecting V-Qtz1 in the mining district where V-519 ore barite veins are also frequently present. Transgranular planes result from the healing of former 520 open cracks [START_REF] Lespinasse | Are fluid inclusion planes useful in structural geology?[END_REF][START_REF] Lespinasse | Microfissural mapping of natural 1071 cracks in rocks: Implications for fluid transfers quantification in the crust[END_REF], and thus more brittle conditions are 521 required than for intragranular planes. As a consequence, Qtz2-ig likely formed at conditions more 522 ductile than Qtz1-tg1, 2. 523 Similar microthermometric phase transitions are observed for Qtz2-ig and Qtz1-tg1, 2 524 (average T h around 340 °C and with comparable maximum salinity). Relative chronology criteria 525 indicate that Qtz1-tg1 predates Qtz1-tg2, but no other direct data allow us to constrain the 526 chronological position of Qtz1-tg (1, 2) in the general fluid history. Two interpretations can be 527

proposed. The dominant NW-SE strike of Qtz1-tg1 may be consistent with late Tortonian 528 shortening directions associated with strike-slip tectonics [START_REF] Montenat | Eastern Betic Neogene basins-a review[END_REF]. This 529 deformation occurred prior to the Messinian N-S to NNE-SSW shortening that could correspond to 530 the subsequent Qtz1-tg2 fluid inclusion planes. In such a scenario, the transgranular fluid inclusions 531 could be coeval with V-ore mineralizing events displaying similar tectonic directions, and thus 532 would not correspond to an early fluid trapped during the brittle-ductile transition. 533 An alternative explanation would be that both kinds of microcracks are related to brittle 534 extensional fracturing, implying that the tectonic regime previously expressed by ductile 535 deformation belongs to an earlier stage of exhumation. In such a case, the brittle deformation would 536 predate the onset of a Late Miocene transcurrent regime related to the mineralizing events. 537 Therefore, σ3 measured normal to the microcracks would be similar for both the extensional and 538 sediments of Serravalian age are preserved further north in the Aguilas block (Griveaud et al., 549 1990). Younger sediments of Late Serravalian -Early Tortonian age recognized further west in the 550 Huercal Overa Basin [START_REF] Pedrera | Intramontane basin 1134 development related to contractional and extensional structure interaction at the termination 1135 of a major sinistral fault: The Huercal-Overa Basin (Eastern Betic Cordillera)[END_REF] are represented by alluvial fan deposits reflecting the 551 uplift of mountain ranges prior to the return of marine conditions in the Vera Basin from Late 552 Tortonian times onwards (Figure 1). The uplift of the Sierra de los Filabres bordering the Huercal 553 Overa Basin has been linked to a local N-S extension (Augier et al., 2005a) or the onset of 554 transcurrent tectonics [START_REF] Montenat | Eastern Betic Neogene basins-a review[END_REF]. Regardless of the associated tectonic 555 regime at this time, the paleogeography suggests that hydrogeological conditions within the brittle 556 crust favoured the input of meteoric water from the uplifted ranges into the upper reservoir, but 557 prior to the Late Tortonian return to marine conditions. 558

Pre-ore fluid stage: The obliquity with respect to the host-rock foliation and the lack of 559 undulose extinction in the euhedral quartz shows that V-Qtz3 formed within the brittle domain. 560 Euhedral Qtz3 formed during the same event that led to the formation of hematite. The input of Fe 561 in the fluid is related here to an increase of salinity. Although oxidizing conditions prevailed at a 562 certain stage of the fluid evolution, it is possible that early siderite was subsequently oxidized. 563 Ore fluid stage: V-ore veins crosscut V-Qtz3 (Figure 4-a). The maximum salinities are 564 observed either in fluid inclusions from transgranular planes within early micro-euhedral quartz on 565 the wall-rock (Qtz-ore-tg), or in primary fluid inclusions from siderite and barite (Sd-p and Brt-p). 566

The formation of siderite postdating V-Qtz3-hematite veins not only indicates the ongoing input of 567 Fe in the fluid, but also a shift towards reducing conditions. Quartz and siderite trapped fluids at 568 lower temperatures (T h of Sd-p around 190 °C) compared with the pre-ore fluid stage (T h of Qtz3-p 569 around 265 °C). V-ore vein sets have two main strike directions: N000E-N340E and N120E-570 N130E. The N-S trend is coherent with the Messinian direction of horizontal shortening and E-W 571 extension, being related to the major transcurrent activity of the Palomares Fault Zone. The 572 interpretation of fluid inclusions in barite is more problematic. The data appears to indicate an 573 increase of T h compared to the estimated conditions of siderite formation (Figure 7), but T h 574 obtained from this kind of mineral are usually considered to be overestimated (Ulrich & Bodnar, 575 1988). This raises the question of the chronological position of N-S to NNE-SSW-striking fluid 576 inclusion planes belonging to Qtz1-tg2, since both Brt-p and Qtz1-tg2 show closely similar Th 577 values and high salinities (Figure 7). It is possible that this similarity is just a coincidence or maybe 578 Qtz1-tg2 inclusions in quartz reflect a thermal pulse that leads to values typical of Brt-p. 579

Late fluid stage: Inclusions in calcite record lower T h around 80 ºC, suggesting formation at a 580 more superficial position. The relative chronology of this late stage in the fluid sequence could be 581 debated since the calcite veins were not sampled in the same structural block as V-ore veins. The 582 only chronological criterion is the crosscutting geometry with V-Qtz2. 583

P-V-T-X evolution 584

The Raman spectrometry study of graphitic schists constrains the maximum temperature 585 attained by the host-rock to 545-587 °C. These results are in agreement with metamorphic peak 586 temperatures of the Nevado-Filábride complex obtained in other parts of the orogen [START_REF] De | Very fast exhumation of high-pressure metamorphic rocks with excess 40Ar 957 and inherited 87Sr, Betic Cordilleras, southern Spain[END_REF], 587 Augier et al., 2005b). 588

D r a f t C o p y

The P-T ranges of fluid inclusion entrapment are constrained by the isochores and geothermal 589 gradients (Figure 11). For the Sierra Almagrera, geothermal gradient data are poorly documented. 590

The only available data comes from the Sierra Nevada located to the West of Sierra Almagrera, 591 where a gradient of 60 °C/km under lithostatic conditions is indicated for the final stages during 592 ductile deformation [START_REF] Gomez-Pugnaire | High-pressure metamorphism in 1013 metabasites from the Betic Cordilleras (S.E. Spain) and its evolution during the Alpine 1014 orogeny[END_REF][START_REF] Bakker | The geodynamic evolution of the 854 Internal Zone of the Betic Cordilleras (south-east Spain): a model based on structural 855 analysis and geothermobarometry[END_REF], Jabaloy et al., 593 1993[START_REF] Augier | 847 Exhumation constraints for the lower Nevado-Filabride Complex (Betic Cordillera, SE 848 Spain): a Raman thermometry and Tweequ multiequilibrium thermobarometry approach[END_REF]. A gradient of 30 °C/km is arbitrarily taken as an upper limit, 594 corresponding to the European average anorogenic gradient. 595

In the absence of other metamorphic constraints, hydrogen isotopes can be used to assess the 596 temperature of equilibrium between fluid inclusions and mica-rich host-rock (Tarantola et al., 597 2007). In the case of isotopic equilibrium, P-T boxes are also constrained by the minimum and 598 maximum values of hydrogen equilibrium temperatures (Table 6 and Figure 11). 599

Early fluid stage: Qtz2-ig inclusion shapes range from euhedral to dismembered (Tarantola et 600 al., 2010 and2012), with large variations of the gas filling ratio. This is indicative of plastic 601 deformation and would thus be related to lithostatic pressure conditions. The box shown in Figure 602 11 is also constrained by minimum and maximum hydrogen equilibrium temperatures since the 603 calculated temperatures are of the order of 400-520 °C (Table 6). 604

Transgranular fluid inclusion planes Qtz1-tg1 and Qtz1-tg2 indicate brittle behaviour within 605 the quartz vein, but the mica-rich host-rock may still have been affected by ductile deformation. 606 Fluids may have been trapped during the brittle-ductile transition of mica-rich lithologies within a 607 temperature and pressure range already corresponding to brittle rheology for the quartz. In such a 608 case, both Qtz1-tg1 and Qtz1-tg2 possibly formed under a lithostatic regime. As an alternative 609 hypothesis, these microcracks may be indicative of a hydrostatic regime due to late Miocene 610 transcurrent tectonics that formed V-ore veins in the brittle domain. In fact, Qtz1-tg1/Qtz1-tg2 611 fluids seem to be in equilibrium with the host-rock (Table 6), but in strong disequilibrium with 612 respect to V-ore veins. In addition, the gas contents of Qtz1-tg1 and Qtz1-tg2 are more closely 613 similar than those of Sd-p and Brt-p fluid inclusions (Table 4). All these data suggest a resident 614 D r a f t C o p y fluid derived from the lower reservoir rather than the presence of fluids of external origin in the 615 upper reservoir. Finally, this explains why Qtz1-tg1 and Qtz1-tg2 could be related to the early fluid 616 stage in the selected scenario (Figure 11). Thus, the rather large T and P range reflects the trapping 617 conditions of inclusions related to this stage between and618 Qtz1-tg1, 2 (440-480 °C and 110-230 MPa) (Figure 11). 619

Intermediate fluid stage: There is no evidence of whether transgranular Qtz2-tg planes formed 620 under a lithostatic or a hydrostatic fluid regime. From this intermediate stage of fluid evolution until 621 the final stages of fluid trapping, the hydrogen isotope fractionation seems to be no longer in 622 equilibrium between the fluid inclusions and the mica-rich host-rock (Table 6). Hydrogen 623 equilibrium temperature constraints do not allow us to define the P-V-T-X boxes. The decrease of 624 salinity related to an input of surficial fluids rather suggests an opening of the system under 625 hydrostatic conditions. The trapping conditions for these fluid inclusions are in the range 300-450 626 °C and 40-140 MPa (Figure 11). 627

Pre-ore fluid stage: Since the euhedral quartz Qtz3 veins were no longer affected by ductile 628 deformation and recrystallization processes, it is considered that they crystallized in the brittle 629 domain under hydrostatic pressure, within the P-T range: 250-380 °C and 40-120 MPa (Figure 11). 630

Ore fluid stage: Crystallization of quartz, siderite and barite occurred in an open system. 631 Hydrostatic conditions allow us to constrain the P-T range of entrapment for fluid inclusions at . 633

Unfortunately, the confidence on microthermometric data obtained on barite is low (Ulrich & 634 Bodnar, 1988). The observed homogenization temperatures would imply a significant increase of 635 the trapping temperature to 280-440 °C at 40-130 MPa. This could be explained by a magmatic 636 input from contemporaneous active volcanism, but it could also be related to an overestimation due 637 to stretched inclusions in barite. T h and salinity of Brt-p are similar to Qtz1-tg2 inclusions, while 638 strike directions of barite V-ore veins are more or less parallel to Qtz1-tg2 fluid inclusion planes. 639

These inclusions in quartz support the hypothesis of a thermal pulse defined by inclusions in barite. 640 In fact, P-V-T-X data from Qtz1-tg2 (Figure 11) seem to indicate a significant increase of pressure 641 compared to Sd-p fluid trapping conditions, which is apparently incompatible with an ongoing 642 exhumation of the Sierra Almagrera. Hydrogen isotopic fractionation indicates a strong 643 disequilibrium between primary fluid inclusions from V-ore veins and the host-rock. On the 644 contrary, hydrogen isotope data for Qtz1-tg2 indicate a fluid in equilibrium, rather suggesting its 645 formation during an early fluid stage. This interpretation does not support the existence of a thermal 646

pulse. 647

Late fluid stage: The calcite stage is characterized by lower homogenization temperatures, 648 suggesting a cooling of the system down to 70-110 °C at 10-30 MPa hydrostatic pressure (Figure 649 11). 650

Source of fluids 651

Early fluid stage: Hydrogen isotope fractionation data showing equilibrium between fluid 652 inclusions and mica-rich host-rock suggest a resident fluid in the lower reservoir. The δD fluid values 653 obtained from Qtz1 (early fluids displaced towards grain boundaries during recrystallization 654 processes) and Qtz2-ig ranging between -23 and -36 ‰ V-SMOW (Table 6, Figure 10) are compatible 655 with a fluid of metamorphic origin. 656 V-Qtz1 quartz grains also containing Qtz1-tg1 and Qtz1-tg2 fluids yield similar δD values (-657 28 to -30 ‰ V-SMOW ). Their halogen signatures plot along the seawater evaporation trend in 658 agreement with halite evaporation (Figure 8). At first sight, this would indicate a primary brine. 659

Two brine sources can be considered according to the geological history: Triassic and Messinian. It 660 is very unlikely that primary brines could have been preserved since Triassic times, considering the 661 metamorphic processes affecting the rocks in the lower reservoir. The other hypothesis would be to 662 explain Qtz1-tg1 and Qtz1-tg2 signatures as representing surficial brines coming from Messinian 663 pre-crisis evaporitic basins. This interpretation revives the hypothesis linking Qtz1-tg2 and Brt-p 664 inclusions during mineralization events. However, stable isotope results and P-V-T-X data rather 665 identify fluids trapped in Qtz1-tg1 and Qtz1-tg2 microcracks as resident fluids that have undergone 666 D r a f t C o p y long-time fluid-rock exchange with the mica-rich host-rock. The interaction of fluids with black 667 graphite schists may have led to a Br enrichment [START_REF] Yardley | 100th Anniversary Special Paper: Metal Concentrations in Crustal Fluids 1196 and Their Relationship to Ore Formation[END_REF] of secondary brines derived from 668 the dissolution of Triassic evaporites, which could explain the position of the data points on the 669 seawater evaporation curve (Figure 8). 670

The variability observed in the salinity of both Qtz2-ig and Qtz1-tg1/Qtz1-tg2 fluids might 671 either reflect i) an original heterogeneity related to discontinuous interaction with Permo-Triassic 672 evaporites, ii) the effect of plastic deformation for Qtz2-ig [START_REF] Diamond | Modification of fluid inclusions in quartz by 962 deviatoric stress. II: experimentally induced changes in inclusion volume and composition[END_REF] 6). This suggests the input of an external low-salinity fluid from the upper reservoir, which 680 did not interact with evaporites/metaevaporites (i.e. Permo-Triassic). 681 It is possible that the volume of low-salinity fluids was sufficient to dilute high-salinity fluids 682 from the early stage, or more likely, the lower ductile and the upper brittle reservoirs were not 683 connected during exhumation and thus behaved independently. The penetration of low-salinity 684 fluids is likely associated with the uplift of mountain ranges during the Serravalian and Early 685

Tortonian [START_REF] Martínez-Martínez | Orthogonal extension in the hinterland of the 1090 Gibraltar Arc (Betics, SE Spain), in Reconstruction of the evolution of the Alpine-1091 Himalayan Orogen[END_REF][START_REF] Platt | From orogenic hinterlands to Mediterranean-style back-arc basins: a comparative 1138 analysis[END_REF] (Figure 12). However, in the absence 686 of δ 18 O values and interpretable LA-ICP-MS data, it cannot be concluded whether this fluid is of 687 meteoric or basinal origin. 688

Pre-ore fluid stage: Hydrogen isotopic composition is not buffered by the host-rock (Table 6). 689

The enrichment of iron in the fluid led also to the formation of hematite in the voids between Qtz3 690 crystals (Figure 4 The salinity is comparable to that in the early fluid stage. δ 18 O quartz is lower than for the early 693 fluid stage, and trapping temperatures define a δD/δ 18 O fluid signature shifted towards 694 basinal/meteoric water compositions. The major and trace elements (Na/K ratio around 50, Sr/Ba 695 ratio around 20 and Sr, Mg content, Table 5) of this fluid reflect a basinal origin [START_REF] Yardley | 100th Anniversary Special Paper: Metal Concentrations in Crustal Fluids 1196 and Their Relationship to Ore Formation[END_REF]. 696

These data are coherent with mixing between low-salinity basinal/meteoric fluids and with an 697 upward migration of high-salinity fluids coming from the lower reservoir. This may reflect the 698 onset of transcurrent tectonics during this period, and a structural connection between the two 699 reservoirs through the brittle ductile transition zone (Figure 12). 700

Ore fluid stage: Although siderite from El Arteal in the mining district yields slightly lower 701 δ 13 C (about 2 ‰, with values of -9.5 and -10.9 ‰ V-PDB ) and slightly higher δ 18 O (about 1 ‰ V- 702 SMOW ), it can be compared with the siderite from Jaroso Ravine (Figure 1-b). The results from this 703 latter locality have been interpreted as indicative of meteoric water and low-temperature 704 hydrothermal conditions [START_REF] Martinez-Frias | 1087 Isotopic signatures of extinct low-temperature hydrothermal chimneys in the Jaroso Mars 1088 analog[END_REF]. However, δ 13 C may also be buffered by the 705 metasedimentary sequence during fluid interaction, whatever the origin of the fluids. 706

The combination of δD and δ 18 O values suggests a fluid with a magmatic or metamorphic 707 signature [START_REF] Field | Light stable isotope systematics in the epithermal 994 environment[END_REF]. As well as having a high salinity, the fluids do not fit the 708 meteoric water line (Figure 10), thus contradicting the conclusions of [START_REF] Martinez-Frias | 1087 Isotopic signatures of extinct low-temperature hydrothermal chimneys in the Jaroso Mars 1088 analog[END_REF]. 709 Since δD fluid is strongly in disequilibrium with the host-rock, this implies an external source for the 710 ore fluid, so it cannot be of meteoric origin. 711 Fluids in siderite were trapped at lower temperatures than the previous fluid stages, and thus 712 at shallower depths (Figure 12). The fluid inclusions in siderite show higher values of salinity than 713 obtained for the earlier stages, reaching up to 25 mass% NaCl eq. (Figure 7, Table 4). Cl/Br data 714

show that the fluid is Br-depleted and far from the seawater evaporation trend. As Br is not easily 715 incorporated in halite, dissolution of halite would yield this type of fluid. Cl/Br ratios thus indicate 716 signatures that could be compared to secondary brines [START_REF] Banks | Emerald mineralisation in 872 Colombia: fluid chemistry and the role of brine mixing[END_REF] resulting from 717 dissolution of evaporites (Figure 8). 718

D r a f t C o p y
The strong salinity increase might result from a combination of volcanism in the Palomares 719 Fault Zone, as suggested by δD and δ 18 O values (Figure 10), and dissolution of evaporites as 720 suggested by their halogen signatures (Figure 8). The strike direction of the veins is coherent with the Messinian strike-slip regime related to major activity of the Palomares Fault Zone (Montenat et 722 al., 1987[START_REF] Booth-Rea | Influence of strike-slip fault 903 segmentation on drainage evolution and topography. A case study: the Palomares Fault 904 Zone (southeastern Betics, Spain)[END_REF]. Of major interest here is the δ 34 S composition of barite, which is 723 more closely comparable to Miocene sea water [START_REF] Claypool | The age curves of sulfur and 941 oxygen isotopes in marine sulfate and their mutual interpretation[END_REF], Morales Ruano et al., 1995) 724 than Triassic values. Therefore, the increase of salinity in the ore fluid stage compared to previous 725 stages could also be related to secondary brines linked to the dissolution of Messinian evaporites 726 rather than exclusively of Triassic evaporites. Dissolution of Messinian marginal evaporites 727 (deposited from 5.96 to 5.67 Ma ago in the Sorbas basin) [START_REF] Clauzon | Alternate interpretation of the 939 Messinian salinity crisis: Controversy resolved?[END_REF], Bourillot et al., 728 2009) is a possible scenario (Figure 12). These Messinian evaporites preceded the main sea-level 729 drop related to the peak of the salinity crisis (5.60-5.46 Ma). Pre-incision Messinian evaporitic 730 deposits were available, as revealed by the "Formation à blocs" in the Vera basin, which reworked 731 Messinian early gypsum during the main incision event (Figure 12) [START_REF] Clauzon | Révision de l'interprétation géodynamique du passage Miocène -Pliocène dans 936 le bassin de Vera (Espagne méridionale) : les coupes d'Antas et de Cuevas del Almanzora[END_REF], Clauzon et al., 732 1996). Messinian sediments from Las Herrerias (Figure 1) were mineralised prior to the main 733 Messinian incision [START_REF] Alvado | Sédimentation, déformation et manifestation magmatiques associées au 828 couloir de décrochement de Palomares : le bassin de Vera (SE de l'Espagne)[END_REF][START_REF] Fortuin | The enigmatic Messinian-Pliocene section of 999 Cuevas del Almanzora (Vera Basin, SE Spain) revisited-erosional features and strontium 1000 isotope ages[END_REF][START_REF] Booth-Rea | Influence of strike-slip fault 903 segmentation on drainage evolution and topography. A case study: the Palomares Fault 904 Zone (southeastern Betics, Spain)[END_REF], and such a scenario 734 would provide a relatively accurate dating of the mineralizing event around 5.65 Ma (Figure 12). 735

A thermal pulse at constant salinity is suspected because the fluid trapping conditions in barite 736 exceed 400 ºC, but this result should rather be considered as an artefact arising from this particular 737 mineral (Figure 12). If the high-K calc-alkaline, shoshonitic and ultrapotassic magmatism were 738 related to mineralization during the ore-fluid stage, this could represent a possible metal source. The 739 high contents of K or metals such Zn or Cu in fluid inclusions (Table 5, Figure 9) tend to support 740 this hypothesis, but a leaching of basement rocks could also be an alternative explanation. 741 represented by the mining district (Figure 12). In such a case, the superficial equivalent of rocks in 746 the central block may have been eroded during the subsequent uplift, but preserved in the subsident 747 block to the West. A second hypothesis is that these calcite veins only developed during a later 748 stage at lower temperature. 749

Fluids trapped as fluid inclusion planes during the early stage are characterized by a rather 750 low density of the CO 2 -rich volatile phase. The significant presence of CH 4 (around 20% of the 751 volatile molar composition) is not strictly expected in the case of water-graphite equilibrium 752 [START_REF] Dubessy | Simulation des équilibres chimiques dans le système C-O-H. Conséquences 965 méthodologiques pour les inclusions fluides[END_REF][START_REF] Huizenga | Thermodynamic modelling of C-O-H fluids[END_REF][START_REF] Huizenga | Thermodynamic modelling of a cooling C-O-H fluid-graphite system: 1036 implications for hydrothermal graphite precipitation[END_REF]. Such a distribution of volatiles is fairly common in 753 metamorphic environments at around 350-450 °C, where local equilibrium is reached between 754 water and graphite. Through mixing with other fluids, this contributes to the common metamorphic 755 signature found in most retrograde fluids during exhumation [START_REF] Cathelineau | Fluid 930 pressure variations in relation to multistage deformation and uplift; a fluid inclusion study of 931 Au quartz veins[END_REF], Boiron et al., 756 2003). At lower temperatures, in the presence of graphite, CH 4 is expected to be the dominant 757 species if redox conditions are moderately reducing. This applies in the case of a predominance of 758 CH 4 in fluid inclusions during the precipitation of siderite at the beginning of the Ore stage, which 759 occurred with a T h around 190 °C. The precipitation of siderite from Fe 2+ -rich solutions requires a 760 significantly low fO 2 and an increase in fCO 2 . 761 crush-leach methods (CL, full symbols) (samples from the mining district). The seawater evaporation trend is indicated 1241 [START_REF] Fontes | Geochemistry and origin of formation brines from the Paris 997 Basin, France: 1. Brines associated with Triassic salts[END_REF] as SW: Seawater, G: Gypsum, H: Halite, E: Epsomite, S: Sylvite, C: Carnallite, B: Bischofite.

Conclusions

1242

Comparison data (crush-leach analysis) in boxes 1 to 4: 1-Variscan fluids equilibrated with host rocks (granite and 1243 metamorphic rocks), [START_REF] Boiron | Mixing of 897 metamorphic and surficial fluids during the uplift of the Hercynian upper crust: 898 consequences for gold deposition[END_REF], 2-Primary brines derived from Triassic evaporites in the Pyrenees (Mccaig 1244[START_REF] Mccaig | Fluid mixing and recycling during Pyrenean 1102 thrusting: evidence from fluid inclusion halogen ratios[END_REF], 3-Primary brines from Ag deposits in Morocco [START_REF] Essarraj | Penetration of 980 surface-evaporated brines into the Proterozoic basement and deposition of Co and Ag at Bou 981 Azzer (Morocco): Evidence from fluid inclusions[END_REF], 4-Secondary brines associated 1245 with emerald mineralization in Columbia [START_REF] Banks | Emerald mineralisation in 872 Colombia: fluid chemistry and the role of brine mixing[END_REF].

1256

Metamorphic and magmatic fluids boxes are plotted from [START_REF] Field | Light stable isotope systematics in the epithermal 994 environment[END_REF]. [START_REF] Boiron | Mixing of 897 metamorphic and surficial fluids during the uplift of the Hercynian upper crust: 898 consequences for gold deposition[END_REF], 2-Primary brines derived from Triassic evaporites in the Pyrenees [START_REF] Mccaig | Fluid mixing and recycling during Pyrenean 1102 thrusting: evidence from fluid inclusion halogen ratios[END_REF], 3-Primary brines from Ag deposits in Morocco [START_REF] Essarraj | Penetration of 980 surface-evaporated brines into the Proterozoic basement and deposition of Co and Ag at Bou 981 Azzer (Morocco): Evidence from fluid inclusions[END_REF], 4-Secondary brines associated with emerald mineralization in Columbia [START_REF] Banks | Emerald mineralisation in 872 Colombia: fluid chemistry and the role of brine mixing[END_REF].

  trapped in quartz and siderite-barite veins record the transfer of fluids and metal 28 solute species during the Neogene exhumation of the Sierra Almagrera metamorphic belt. Ductile 29 then brittle-ductile extensional quartz veins formed from a deep fluid reservoir, trapping 30 metamorphic secondary brines containing low-density volatile phases derived from the dissolution 31 of Triassic evaporites. During exhumation, low-salinity fluids percolated within the brittle domain, 32 as shown by transgranular fluid inclusion planes affecting previous veins. These observations 33 indicate the opening of the system during Serravalian to early Tortonian times, and provide 34 evidence for the penetration of surficial fluids of meteoric or basinal origin into the upper part of the 35 brittle-ductile transition. 36

  cordillera during the Miocene (between 18 to 14 Ma:[START_REF] Gomez-Pugnaire | A reinterpretation of the Nevado-Filabride and 1017 Alpujarride Complexes (Betic Cordillera): Field, petrography and U-Pb ages from 1018 orthogneisses (western Sierra Nevada, S Spain)[END_REF], lower and upper crustal reservoirs during the Miocene extensional tectonics, the 105 effect of transcurrent deformation on the hydrogeological configuration, the possible fluid sources 106 at the various stages of this evolution and the timing of mineralizations in the region.

  -b). 188Mineralizations in the Sierra Almagrera are found in veins within the metamorphic rocks of 189 the currently uplifted metamorphic range (Figure1-b). In the present study, this formerly exploited 190 area is referred to as the Sierra Almagrera mining district. While some mineralised veins are 191 exposed at outcrop in the Sierra, the sulphides are frequently oxidized. Non-altered veins can still 192 be sampled along the E-W striking horizontal gallery at El Arteal. Subvertical fractures filled by 193 siderite, barite, hematite and ore minerals crosscut the metamorphic fabric of graphitic schists and 194 quartz veins transposed or partly transposed within the main rock foliation. Our study shows that 195 the mineralised fractures are arranged in two main clusters striking N160°-N180° and N120°-N130° 196 (Figure1-c). 197

  150-200-µm-thick sections were prepared for microscopic and 205 microthermometric observations of mineralized veins of quartz, siderite, barite and calcite. The 206 sections were oriented (using azimuth convention) to determine present-day strike and dip of fluid 207 Isolated fluid inclusions or clusters are interpreted as primary. Intragranular fluid 208

  This technique allows direct ablation of individual fluid inclusions within the host mineral, 259 represented in the present study by quartz, siderite and barite. The LA-ICP-MS instrument 260 (GeoRessources laboratory, Vandoeuvre-lès-Nancy, France) comprises a GeoLas excimer laser 261 (ArF, 193 nm, Microlas, Göttingen Germany) and an Agilent 7500c quadrupole ICP-MS equipped 262 with an octopole reaction-cell using H 2 gas, and a collision-cell using He gas. The laser beam is 263 focused onto the sample within an ablation cell with a Schwarzschild objective (magnification x25) 264 linked with a CCD camera. Synthetic glass provided by the National Institute of Standards and 265 Technology (NIST) is used for calibration of the different analysed elements and respective masses 266

  ). 357 These quartz veins are characterised by high-temperature recrystallization mechanisms with 358 granoblastic euhedral texture, with grains of about 200 µm showing triple points with an angle of 359

  (Figure 2-c). No primary inclusions are 361 observed in Qtz1 grains, and transgranular fluid inclusion planes are only observed in the Sierra 362 Almagrera mining district. Relative chronology criteria indicate that Qtz1-tg1 predates Qtz1-tg2. 363 Each set of plane displays a distinct orientation (Figure 2-d-e-f; Table

  -b). Microstructures 371 indicate dynamic recrystallization processes at slightly lower temperatures than V-Qtz1 (Figure 3-b; 372 Passchier & Trouw, (2005)). Fluid inclusions in V-Qtz2 are found within intragranular (Qtz2-ig) 373 (Figure 3-b-c) or transgranular planes (Qtz2-tg) (Figure 4-a-b-e). The direction and dip of Qtz2-ig 374 fluid inclusion planes are randomly distributed (Figure 3-e) throughout the vein, but are parallel to 375 each other within a single grain. This suggests that these veins are related to crystallographic 376 directions reactivated during crystal plastic deformation rather than tectonic fracturing. Qtz2-tg 377 veins are parallel to each other and to the walls of V-Qtz2 (Figure 4-b-e). They were likely 378 produced by crack-and-seal deformation. 379 4.2.3 V-Qtz3, oblique veins from the mining district 380 V-Qtz3 are composed of euhedral quartz associated with hematite, developed in veins 381 (thickness < 5 cm) oblique to the host-rock foliation or in voids. Although euhedral Qtz3 overgrows 382 Qtz2 (Figure 4-b), it is never intersected by Qtz2-tg. Isolated primary fluid inclusions are 383 interpreted as contemporaneous to crystal growth (Qtz3-p; Figure 4-f). Hematite is found within 384 microfissures extending from the wall rock to Qtz2 (Figure 4-b-d) and in voids between euhedral 385 4-a-b). The lack of microfractures affecting Qtz3 and the almost systematic 386 association of Qtz3 with hematite minerals suggest that both minerals grew during the same 387 mineralization event. 388

Page

  data concerning the size, shape and filling of the fluid inclusions. The 409 characteristic phase-transition temperatures and calculated compositions of fluid inclusions are 410

  inclusions in Qtz, Sd and Brt from V-ore veins 436

  the δ 18 O values of minerals containing fluid inclusions. White micas from the 487 host-rock yield δD values of -52 ± 1 ‰ V-SMOW . δD fluid values from Qtz1 sampled in the subsident 488 area (recrystallised quartz devoid of visible inclusions) range between -33 and -36 ‰ V-SMOW . 489

  criteria to reconstruct the fluid sequence 504 Early fluid stage: Ductile deformation affecting V-Qtz1 and V-Qtz2 in the Sierra Almagrera 505

  with the result that this question cannot be resolved solely on the basis of 539 structural criteria. If fluids were trapped soon after the ductile-brittle transition for quartz, this 540 would explain certain similarities of the microthermometry and salinity data with Qtz2-ig fluid 541 inclusions trapped during this transition. 542 Intermediate fluid stage: Qtz2-tg fluids are characterised by a much lower salinity than 543 observed in the other types of fluid inclusions. Since Qtz2-tg never affects V-Qtz3 nor V-Cal, this 544 suggests an episodic arrival of low-salinity fluid after the formation of V-Qtz2 but prior to V-Qtz3 545 and V-Cal. Considering the youngest ages inferred for ductile deformation in the eastern Betics 546 (around the Langhian-Serravalian boundary), the exhumation of this part of the Sierra Almagrera 547 within the brittle domain probably occurred during Langhian to Serravalian times. Only marine 548

  , or iii) a mixing 673 between deep high-salinity and a low-salinity fluid end-members. 674 Intermediate fluid stage: Fluid isotope values obtained on Qtz2 grains containing Qtz2-tg also 675 incorporate the signature of fluids from the early stage displaced to grain boundaries during 676 recrystallization processes. δD fluid values ranging from -17 to -48 ‰ V-SMOW are generally lower 677 than values obtained for the early fluid stage. δD values of the dilute fluid are thus D-depleted 678 compared to those of the early stage, with values that are unlikely to be buffered by the host-rock 679 (Table

  . This stage corresponds to tectonic conditions in the brittle

  Late fluid stage: Homogenization temperatures of fluid inclusions within calcite around 80 ºC 742 suggest deep burial or a shallow expression of hot fluids. The salinity of these fluids may be 743 compared to the salinity of early and pre-ore stages. Calcite veins may correspond to a shallow 744 fluid flows, recorded as veins currently cropping out in the uplifted block 745

762STFigure 2 Figure 5 :Figure 7 :Figure 8 :

 2578 Figure 2: a) V-Qtz1 quartz vein parallel to the rock foliation. b) Optical microphotograph under cross-polarized light

1246 1247Figure 9 :

 12469 Figure 9 : Box-and-whisker plots showing the concentrations of various elements concentrations (in ppm) in fluid

Figure 12 :

 12 Figure 11: P (MPa) vs. T (°C) of fluid inclusion stages in the Sierra Almagrera. l.p.: geothermal gradient at lithostatic

  context of the Eastern Betics and location of the Sierra Almagrera (modified after Augier (2004)). b) Geological map of the Sierra Almagrera, Vera basin and Palomares fault zone (modified after Booth-Rea (2004) and Montenat & Ott D'estevou (1990), and location of sampling areas. c) Poles of mineralized V-ore veins (barite and siderite) in El Arteal tunnel represented on lower--Qtz1 quartz vein parallel to the rock foliation. b) Optical microphotograph under cross-polarized light (XPL) showing petrography of Qtz1: static recrystallization (120° angles) and grain boundary migration recrystallization. c) Qtz1: recrystallised quartz with transgranular FIP. d) Qtz1-tg1 FIP. e) Qtz1-tg2 FIP. f) Pole projections of Qtz1-tg1 and Qtz1-tg2 fluid inclusion planes represented on lower hemisphere stereogram. Arrows indicate the directions of opening. L for liquid, V for vapour and S for solid. 126x100mm (300 x 300 DPI) quartz vein locally parallel to the foliation (upper part), while the main section is discordant to the foliation (central part). b) Relationship between petrography of recrystallised quartz (subgrain rotation and bulging) and fluid inclusions. c) Optical microphotographs under plane-polarized light showing intragranular Qtz2-ig. d) Deformed fluid inclusion Qtz2-ig. e) Pole projections of Qtz2-ig fluid inclusion planes represented on lower-hemisphere stereogram. 133x88mm (300 x 300 DPI) V-Qtz2 discordant to the foliation reopened as V-Qtz3, intersected by V-ore discordant vein. Optical microphotographs under natural light: b) Contact between Qtz2 and Qtz3. Qtz2 grains still showing undulose extinction and affected by Qtz2-tg. Qtz3 euhedral quartz containing only Qtz3-p primary fluid inclusions. Hematite microfissures affecting Qtz2. Hematite also filling open spaces between Qtz3 crystals. c) Zoom of zone localized in b). d) Hematite in reflected light. e) Qtz2-tg. f) Qtz3-p. 239x113mm (300 x 300 DPI) Optical microphotographs of V-ore and related minerals, in plane-polarized light (PPL), cross-polarized light (XPL) and reflected light (RL). a) Vein of siderite and micro-euhedral quartz (XPL). b) Sequence of siderite, galena and barite (PPL+ RL). c) Schematic representation of chloritoid-schist breccia cemented by various minerals (V-ore). d) Sd-p primary fluid inclusion in siderite. e) Brt-p in barite. 110x103mm (300 x 300 DPI) oblique quartz vein intersected by V-Cal oblique calcite vein. b) Relationships between V-Qtz2 grains, Qtz2-tg and calcite vein containing Cal-p. c) Detail of Cal-p. 161x44mm (300 x 300 DPI) Microthermometry and salinity data for all types of fluid inclusions from the Sierra Almagrera. 124x63mm (300 x 300 DPI) molar ratio vs. Cl concentration for fluid inclusions analysed both by LA-ICP-MS (empty symbols) and crush-leach methods (CL, full symbols) (samples from the mining district). The seawater evaporation trend is indicated (Fontes & Matray, 1993) as SW: Seawater, G: Gypsum, H: Halite, E: Epsomite, S: Sylvite, C: Carnallite, B: Bischofite. Comparison data (crush-leach analysis) in boxes 1 to 4: 1-Variscan fluids equilibrated with host rocks (granite and metamorphic rocks),

  Abbreviation Observation -p Primary fluid inclusion -ig Intragranular fluid inclusion plane -tg Transgranular fluid inclusion plane L Liquid V Vapour S Solid flw Volume fraction of aqueous liquid T e Eutectic or apparent eutectic temperature. First formation of visible liquid of solid aqueous phase on heating T m (ice) Final melting temperature of solid aqueous phase T m (cla) Dissociation temperature of clathrate T h (L) Bulk homogenization temperature via bubble-point transition (L+V=L) T h (V) Bulk homogenization temperature via dew-point transition (L+V=V)

. Characteristics of the host-rock 336

	335	4. Results
		4.1
		D r a f
		t
		C o
		p y
	333	at a given temperature.
	334

Table 1 :

 1 Abbreviations referring to microthermometric experiments. .

	1265
	1266

Table 2 :

 2 Nomenclature, location and description of sampled veins

	1267
	1268

Table 3 :

 3 Nomenclature, chronology and characteristics of fluid inclusions. Abbreviations: -tg stands for transgranular, -

	1269
	1270	ig for intragranular and -p for primary, L: liquid, V: vapour, acc.: accidentally trapped mineral, Sd: siderite, Brt: barite,
	1271	Cal: calcite.
	1272

Table 4 :

 4 Microthermometric and compositional data for all generations of fluid inclusions from the Sierra Almagrera

	1273
	1274	(values of mode in italics). -: not determined
	1275

Table 5 :

 5 LA-ICP-MS data for four generations of fluid inclusions from the Sierra Almagrera. Concentrations are given

	1276
	1277	in ppm and Na/K are mass ratios. -: not determined

Table 6 :

 6 Isotopic data for various stages of fluid inclusions from the Sierra Almagrera, -: not determined.

Table :

 : Abbreviations referring to microthermometric experiments. .

	Page 55 of 60	Geofluids
	1
		D r a f
		t
		C o
		p y
		Geofluids

around 5.65 Ma, prior to the main Messinian salinity crisis.

Geofluids

Acknowledgments

-1025

(1) Obtained from isochore intersection with PT-path 1

(2) Equation of [START_REF] Zheng | Calculation of oxygen isotope fractionation in anhydrous silicate minerals[END_REF] for quartz-H 2 O fractionation; equation of Zheng (1999)