A model of lacustrine sedimentation for the Early Pleistocene deposits of Guadix-Baza basin (southeast Spain) José Manuel García-Aguilar * , Paul Palmqvist Departamento de Ecología y Geología (Área de Paleontología), Facultad de Ciencias, Campus Universitario de Teatinos, 29071-Málaga, Spain article info Article history: Available online 19 February 2011 abstract The Early Pleistocene deposits of Guadix-Baza basin represent a depositional unit with distinctive features in the tectosedimentary history of this intramontane basin, which sedimentary infillings range in age between the uppermost Miocene and 45 ka. This Pleistocene unit has an average thickness of 10 m and is composed of carbonate lacustrine facies arranged in an upward-shallowing sequence. The pale- ontological richness of this unit is evidenced by its special sedimentological and paleoecological features. Diverse numerical analytic data related with the evolution of the sedimentary sequences and the establishment of the sedimentary and paleoecological scenario are presented. Ó 2011 Elsevier Ltd and INQUA. All rights reserved. 1. Introduction The region of Guadix-Baza (Granada, SE Spain) is a w100 km long, NEeSW directed intramontane basin situated in the contact between the Internal and External Zones of the Betic Chains (Fig. 1). This basin preserves the thickest and most continuous record of continental Plio-Pleistocene sediments of the Iberian Peninsula, showing two depocenters (Guadix and Baza subbasins) separated by a threshold linked to substrate outcrops (Jabalcón mountain, 1494 m). There is a well-known structural control of this basin, which results from the action of N50e70E and N150e170E fractures as well as from the presence of a tectonic accident, the Negratín shearing fault, which is part of a major system that crosses the Betic Chains from one extreme to the other following a NEeSW direction. The continental sediments of this basin are dated between the Turolian (Late Miocene) and the Late Pleistocene (Fig. 2), which cluster in two main sedimentary packages (García-Aguilar and Martín, 2000) with 300 m total thickness dated as Turolian and Plio-Pleistocene, respectively. The Plio-Pleistocene sedimentary infillings comprise five tectosedimentary units (García-Aguilar, 1997) limited by sedimentary discordances linked to hiatuses. The oldest of these is a Early Pliocene lacustrine-carbonate unit and the rest of sediments are composed of diverse alluvial and carbo- nateemarlyeevaporitic lacustrine units related laterally and verti- cally by a model of stratigraphic architecture which is complex in detail. The Guadix-Baza basin was endorheic (i.e., characterized by interior drainage) until very recent times (43 ka), in which the capture of its waters by the Guadiana Menor, a tributary of the Guadalquivir River, led to strong erosive processes resulting in the predominance of badland landscapes with w200 mm of annual precipitation inside the basin (Viseras, 1991; Fernández et al., 1996; Azañón et al., 2006). However, it is worth noting that an age in excess of 180 ka has been recently assigned for this endo- rheiceexorheic transition (García-Tortosa et al., 2008). Subrecent (w5 ka) travertine deposits up to 10 m thick associated to thermal upwellings aligned with the major fracture systems of the basin are found locally (García-Aguilar, 1997). 2. Objectives The main objective of this article is to develop a model of lacustrine sedimentation for the Early Pleistocene deposits of the Guadix-Baza basin using the sedimentological and paleontological data available, which will allow establishing their patterns of lateral and vertical evolution. The second objective is to use this model in the sedimentary reconstruction of the main paleontological local- ities of the Orce area, particularly Venta Micena. 3. Architecture of the continental infillings The Guadix-Baza basin is exceptional from a stratigraphic point of view, given the quality of exposure of the outcropping areas and their lateral and vertical continuity, the density of paleontological sites (e.g., Cuevas et al.,1984; Ruiz-Bustos et al.,1984; Martín-Suárez, 1988; Soria and Ruiz-Bustos,1991,1992; Sesé,1994; Palmqvist et al., * Corresponding author. E-mail addresses: chemacyanos@msn.com (J.M. García-Aguilar), ppb@uma.es (P. Palmqvist). Contents lists available at ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint 1040-6182/$ e see front matter Ó 2011 Elsevier Ltd and INQUA. All rights reserved. doi:10.1016/j.quaint.2011.02.008 Quaternary International 243 (2011) 3e15