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© 2015 Elsevier B.V. The Logrosán Sn-(W) ore deposits in the metallogenic Sn-W province of the European Variscan Belt consist of endo- and exogranitic greisen-type and quartz-cassiterite veins associated with a S-type granite. Mineral characterization, fluid inclusion study, isotope geochemistry and Ar-Ar geochronology have been combined in order to reconstruct the conditions for Sn-(W) mineralization. The endo- and exogranitic mineralization must have been developed in a relatively long-lived system (~308-303Ma), during or soon after the emplacement of the Logrosán related-granite (at ca. 308Ma). The mineralizing fluids are characterized by complex aqueous and volatile (H2O-N2-CO2-CH4-NaCl) fluid inclusions. Microthermometry and Raman analyses indicate that fluid composition evolved from N2-CH4 to N2-rich, followed by CO2-rich fluids, with varying amounts of H2O. The presence of N2 and CH4 suggests the interaction with fluids derived from the nearby metasedimentary host rocks. A model of host-rock interaction, assimilation, and mixing of metamorphic and magmatic fluids, resulting in change of the redox conditions, is proposed for tin deposition. Later sulfide minerals were precipitated as a result of pressure and temperature release., This work was financially supported by the projects CGL2012-32822 (Ministerio de Economía y Competitividad of Spain) and the 910492 (Universidad Complutense de Madrid).

International audience; Fluid inclusions trapped in quartz veins hosted by a leucogneiss from the southern part of the Naxos Metamorphic Core Complex (Attic-Cycladic-Massif, Greece) were studied to determine the evolution of the fluid record of metamorphic rocks during their exhumation across the ductile/brittle transition. Three sets of quartz veins (V-M2, V-BD & V-B) are distinguished. The V-M2 and V-BD are totally or, respectively, partially transposed into the foliation of the leucogneiss. They formed by hydrofracturing alternating with ductile deformation accommodated by crystal-plastic deformation. The V-B is discordant to the foliation and formed by fracturing during exhumation without subsequent ductile transposition. Fluids trapped during crystalplastic deformation comprise two very distinct fluid types, namely a CO2-rich fluid and a high-salinity brine, that are interpreted to represent immiscible fluids generated from metamorphic reactions and the crystallization of magmas respectively. They were initially trapped at approximate to 625 degrees C and 400MPa and then remobilized during subsequent ductile deformation resulting in various degrees of mixing of the two end-members with later trapping conditions of approximate to 350 degrees C and 140MPa. In contrast, brittle microcracks contain aqueous fluids trapped at 250 degrees C and 80MPa. All veins display a similar 13C pointing to carbon that was trapped at depth and then preserved in the fluid inclusions throughout the exhumation history. In contrast, the D signature is marked by a drastic difference between (i) V-M2 and V-BD veins that are dominated by carbonic, aqueous-carbonic and high-salinity fluids of metamorphic and magmatic origin characterized by D between 56 parts per thousand and 66 parts per thousand, and (ii) V-B veins that are dominated by aqueous fluids of meteoric origin characterized by D between 40 parts per thousand and 46 parts per thousand. The retrograde PT pathway implies that the brittle/ductile transition separates two structurally, chemically and thermally distinct fluid reservoirs, namely (i) the ductile crust into which fluids originating from crystallizing magmas and fluids in equilibrium with metamorphic rocks circulate through a geothermal gradient of 30 degrees C km1 at lithostatic pressure, and (ii) the brittle upper crust through which meteoric fluids percolate through a high geothermal gradient of 55 degrees C km1 at hydrostatic pressure.

The geometry of the ore fluid migration was investigated in the (W-Sn) mineralizated granites of the Spanish Central System. Based on microthermometry, Raman microprobe and textural relationships, six types of fluid inclusions have been distinguished: 1) Magmatic hypersaline aqueous fluid represented by Lw-s inclusions. 2) Metamorphic aquo-carbonic fluids represented as different types of fluid inclusions: (i) H20 - C02-(CH4) fluids represented by Vc-w three phase inclusions at room temperature; (ii) H 20 - C 0 2-CH4 fluids showing two-phase at room temperature with a low density volatile phase displaying a large variation of the CH4/C02 ratio; (iii) H20-CH4 fluids represented by Lw-m two-phase inclusions with a volatile phase entirely dominated by CH4.3) Aqueous fluid sare shown by (iv) Lw1 and (v) Lw2 two phase in elusions with low to moderate salinity. Fluid trapping occurred in the granites by means of a complex succession of opening and reopening of microfracture network. NE-SW ductile-brittle cracks contains quartz-wolframite thus connected with FIP bearing aqueous-carbonic fluids. A later drop in C02 es recorded in N140°-150°E, N 100°-110°E, N-S and E-W. A latest fluid is represented by aqueous fluids crosscutting the precedent fluid inclusions planes

The geometry of the ore fluid migration was investigated in the (W-Sn) mineralizated granites of the Spanish Central System. Based on microthermometry, Raman microprobe and textural relationships, six types of fluid inclusions have been distinguished: 1) Magmatic hypersaline aqueous fluid represented by Lw-s inclusions. 2) Metamorphic aquo-carbonic fluids represented as different types of fluid inclusions: (i) H20 - C02-(CH4) fluids represented by Vc-w three phase inclusions at room temperature; (ii) H 20 - C 0 2-CH4 fluids showing two-phase at room temperature with a low density volatile phase displaying a large variation of the CH4/C02 ratio; (iii) H20-CH4 fluids represented by Lw-m two-phase inclusions with a volatile phase entirely dominated by CH4.3) Aqueous fluid sare shown by (iv) Lw1 and (v) Lw2 two phase in elusions with low to moderate salinity. Fluid trapping occurred in the granites by means of a complex succession of opening and reopening of microfracture network. NE-SW ductile-brittle cracks contains quartz-wolframite thus connected with FIP bearing aqueous-carbonic fluids. A later drop in C02 es recorded in N140°-150°E, N 100°-110°E, N-S and E-W. A latest fluid is represented by aqueous fluids crosscutting the precedent fluid inclusions planes