Salt deposition and brine evolution in the Granada Basin (Late Tortonian, SE Spain)
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Elsevier Science BV
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.
Evaporites, Salinity, Halite, Bromine, Sedimentary basins, Sulfates, Spain
García-Veigas, J., Cendón, D.I., Rosell, L., Orti, F., Torres Ruiz, J., Martín, J.M., & Sanz, E. (2013). Salt deposition and brine evolution in the Granada Basin (Late Tortonian, SE Spain). Palaeogeography, Palaeoclimatology, Palaeoecology, 369, 452-465. doi:10.1016/j.palaeo.2012.11.010