Pleistocene Lacustrine Basin of the East Domain of Guadix-Baza Basin (Granada, Spain): Sedimentology, Chronostratigraphy, and Palaeoenvironment
PLEISTOCENE LACUSTRINE BASIN OF THE EAST DOMAIN OF GUADIX-BAZA BASIN (GRANADA, SPAIN): SEDIMENTOLOGY, CHRONOSTRATIGRAPHY, AND PALAEOENVIRONMENT 2 TRINIDAD TORRES 1, JOSÉ EUGENIO ORTIZ', VICENTE SOLER , E. REYES) , 3 4 1 ANTONIO DELGAD0 , MARUJA VALLE , JUAN FRANCISCO LLAMAS , RAFAEL s 7 COBO , RAMÓN JULLA/', ERNESTINA BADAL , MIGUEL ÁNGEL GARCÍA DE LA 1 s MORENA', MARÍA JESÚS GARCÍA-MARTÍNEZ , JORGE FERNÁNDEZ-GIANOTTI , 9 JOSÉ PEDRO CALV0 , ANTONIO CORTÉS 10 , Laboratorio de Estratigrafía Biomolecular. E.T.S.1. Minas, Madrid 2 Instituto de Agrobiología y Productos Naturales (CSlC), La Laguna (Tenerife). 3 Estación Experimental del Zaidín (CSIC), Granada 4 Opto de Paleontología, Universidad de Salamanca 5 CEOEX, Madrid. 6 Instituto de Ciencias de la Tierra Jaume Almera (CSIC), Barcelona. 7 Opto. de Prehistoria y Arqueología. Universidad de Valencia 8 Instituto Geológico y Minero de España, Madrid 9 Opto. de Petrología y Geoquímica, Universidad Complutense de Madrid 10 Empresa Nacional de Residuos Radiactivos, Madrid. ABSTRACT We present the study of the lacustrine deposits of the eastern part of the Guadix Baza basin (GBE), an intramontanous basin which remained isolated from erosive conditions until upper Middle Pleistocene times. The facies distribution shows a clear centripetal pattern, with alluvial fan systems reaching the GBE through still visible gorges, all of them which were fed by run-off as well as groundwater from karst with dissolved sulphates from marine Miocene and Upper Triassic age evaporites. A complex system of sandy beaches, mud flat playa and marginal lacustrine sands connccted central lacustrine environments and marginal alluvial fans (sheet flow deposits). After fíeld measurements, paleomagnetism determinations and amino acid racemisation, a "composite-stratotype-section" was established that provided a time-and-space framework for the GBE lacustrine deposits.
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