The "Laguna de San Benito" (Valencia, Spain): Palaeoenvironmental reconstruction of an endorheic system

This work relates in part to the general object of a wider project, whose aim is to establish the palaeogeographical and palaeoenvironmental evolution of several endorheic areas in the external units of the Betic Ranges (western part of Valencia and northern part of Albacete) in Spain. With this purpose, multidisciplinary studies have been carried out. The structural basin where San Benito lake ("laguna") lies has a tectonic origin and has suffered tectonic phases since Middle Miocene. During the Quaternary, it has been filled by alluvial deposits, originated in the neighboring relief and subsequently affected by tectonic movements. Stratigraphical and sedimentological analysis of a 25 m core, with absolute datings between 110000 ± 17000 BP and 1410 ± 80 BP, show moments of extension of the lacustrine environment and phases of reduction with pro gradation of the detritic contributions of the slopes. These phases of major or minor stability of the basin probably correspond to climatic fluctuations without forgetting the importance of the tectonic factor and are visible in micropaleontological results. The palynological analysis of the upper levels shows how edaphic factors and human impact may complicate a climatic interpretation of the landscape, for the late Holocene, in semi-arid zone.