Browsing by Author "Torres Ruiz, J"

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    Salt deposition and brine evolution in the Granada Basin (Late Tortonian, SE Spain)
    (Elsevier Science BV, 2013-01-01) García-Veigas, J; Cendón, DI; Rosell, L; Orti, F; Torres Ruiz, J; Martín, JM; Sanz, E
    A group of sedimentary basins in the Betic Chain were formed during the Middle-Late Miocene as a result of the closure of the Tethys during the Alpine orogeny. In the Late Miocene (Tortonian-Messinian) the connections between the Atlantic Ocean and Mediterranean Sea were interrupted and those basins hosted major evaporites. The Granada Basin, an 'inner basin' located far from the Mediterranean, contains a thick rock salt deposited during the latest Tortonian in the transition from marine to non-marine conditions. In the centre of the basin, three halite-bearing units overlie a basal anhydrite bed: the Lower Halite Unit, the Intermediate Sandstone Unit and the Upper Halite Unit. Fluid inclusion compositions and bromine concentrations in halite, together with stable isotopes (delta S-34(sulfate), delta O-18(sulfate) and Sr-87/Sr-86) indicate a mixture of different inflow waters in the Granada Basin, beginning with a marine lagoon that evolved into a salt-pan strongly isolated from the sea. Saline waters evolved from sulfate-rich marine-derived to sulfate-depleted non-marine brines influenced by the addition of CaCl2-rich inputs. These CaCl2-rich waters were probably linked to thermal fluids associated with a major crustal fracture system (Crevillente or Cadiz-Alicante fault system) that cuts through the Granada Basin. © 2013, Elsevier Ltd.