Browsing by Author "Sanz, E"

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    Late Miocene evaporite geochemistry of lorca and fortuna basins (Eastern Betics, SE Spain): evidence of restriction and continentalization
    (Wiley, 2020-09-26) García‐Veigas, J; Gibert, L; Cendón, DI; Artiaga, D; Corbí, H; Soria, JM; Lowenstein, TK; Sanz, E
    The Lorca and Fortuna basins are two intramontane Neogene basins located in the eastern Betic Cordillera (SE Spain). During the Late Tortonian—Early Messinian, marine and continental evaporites precipitated in these basins as a consequence of increased marine restriction and isolation. Here we show a stratigraphic correlation between the evaporite records of these basins based on geochemical indicators. We use SO4 isotope compositions and Sr isotopic ratios in gypsum, and halite Br contents to characterize these units and to identify the marine or continental source of the waters feeding the evaporite basins. In addition, we review the available chronological information used to date these evaporites in Lorca (La Serrata Fm), including a thick saline deposit, that we correlate with the First Evaporitic Group in Fortuna (Los Baños Fm). This correlation is also supported by micropalaeontological data, giving a Late Tortonian age for this sequence. The Second Evaporitic Group, (Chicamo Fm), and the Third Evaporitic Group (Rambla Salada Fm) developed only in Fortuna during the Messinian. According to the palaeogeographical scheme presented here, the evaporites of the Lorca and Fortuna basins were formed during the Late Tortonian—Early Messinian, close to the Betic Seaway closure. Sulphate isotope compositions and Sr isotopic ratios of the Ribera Gypsum Mb, at the base of the Rambla Salada Fm (Fortuna basin), match those of the Late Messinian selenite gypsum beds in San Miguel de Salinas, in the near Bajo Segura basin (40 km to the East), and other Messinian Salinity Crisis gypsum deposits in the Mediterranean. According to these geochemical indicators and the uncertainty of the chronology of this unit, the assignment of the Rambla Salada Fm to the MSC cannot be ruled out. © 1999-2024 John Wiley & Sons, Inc or related companies.
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    Late Miocene evaporite geochemistry of Lorca and Fortuna basins (Eastern Betics, SE Spain): Evidence of restriction and continentalization
    (John Wiley & Sons, Inc., 2019-09-26) García-Veigas, J; Gilbert, L; Cendón, DI; Artiaga, D; Corbí, H; Soria, JM; Lowenstein, TK; Sanz, E
    The Lorca and Fortuna basins are two intramontane Neogene basins located in the eastern Betic Cordillera (SE Spain). During the Late Tortonian—Early Messinian, marine and continental evaporites precipitated in these basins as a consequence of increased marine restriction and isolation. Here we show a stratigraphic correlation between the evaporite records of these basins based on geochemical indicators. We use SO4 isotope compositions and Sr isotopic ratios in gypsum, and halite Br contents to characterize these units and to identify the marine or continental source of the waters feeding the evaporite basins. In addition, we review the available chronological information used to date these evaporites in Lorca (La Serrata Fm), including a thick saline deposit, that we correlate with the First Evaporitic Group in Fortuna (Los Baños Fm). This correlation is also supported by micropalaeontological data, giving a Late Tortonian age for this sequence. The Second Evaporitic Group, (Chicamo Fm), and the Third Evaporitic Group (Rambla Salada Fm) developed only in Fortuna during the Messinian. According to the palaeogeographical scheme presented here, the evaporites of the Lorca and Fortuna basins were formed during the Late Tortonian—Early Messinian, close to the Betic Seaway closure. Sulphate isotope compositions and Sr isotopic ratios of the Ribera Gypsum Mb, at the base of the Rambla Salada Fm (Fortuna basin), match those of the Late Messinian selenite gypsum beds in San Miguel de Salinas, in the near Bajo Segura basin (40 km to the East), and other Messinian Salinity Crisis gypsum deposits in the Mediterranean. According to these geochemical indicators and the uncertainty of the chronology of this unit, the assignment of the Rambla Salada Fm to the MSC cannot be ruled out. © 2019 The Authors. Basin Research © 2019 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
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    Marine to lacustrine evolution in an evaporitic environment: the late miocene Lorca Basin, Spain
    (U.S. Department of the Interior and U.S. Geological Survey, 2015-06-15) García-Veigas, J; Cendón, DI; Gilbert, L; Rosell, L; Ortí, F; Playà, E; Prats, E; Soria, JM; Corbí, H; Sanz, E
    The Lorca Basin, in the eastern sector of the Betic Range (SE Spain), is an intramontane basin recording an evaporitic succession (La Serrata Formation), of up to 300 m thick, with a ~ 235 m thick saline unit within. Altogether, the evaporitic record was originally interpreted as Messinian (Geel, 1976) and later assigned to Tortonian (Krijgsman and others, 2000). The detailed geochemical study provides relevant paleogeographic information at local scale and highlights the importance of hydrochemical changes taking place in coastal evaporite basins changing between marine and non-marine conditions without lithological variations. A stratigraphic framework is proposed correlating the outcropping gypsum beds (Gypsum Mb of La Serrata Fm) and the subsurface saline succession (Halite Mb) by means of strontium and sulfate isotopes (fig. 1). In the lower part of the Gypsum Mb the isotopic trends suggest that gypsum formed from marine waters while in the upper part, with Triassic isotopic signals, gypsum formed in a coastal lake mainly fed by non-marine waters. In the Halite Mb, the textures indicate precipitation in a very shallow, often dried, environment. Fluid inclusion compositions and bromine contents in salt show an evolution from normal marine brines, to brines resulting from the recycling of previously precipitated halite essentially by means of non-marine waters in a coastal lake setting. The overlying Laminated Pelite Mb (Geel, 1976) consists in its lower part of a number of non-marine gypsum beds intercalated between marine marls suggesting post-evaporitic refilling events of the Lorca Basin by the Mediterranean Sea before its final continentalization during the Pliocene. Biostratigraphic studies in progress are expected to refine age allocation within the evaporitic unit and therefore improve our understanding of the relationship to the “Messinian Salinity Crisis”. © 2015 The Authors
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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.