Geoarchaeological and Chronostratigraphic study of the Upper Pleistocene record of the Cierro cave (Fresno, Ribadesella, Asturias, Spain)

Abstract

The Cierro Cave (Fresno, Ribadesella, Asturias) is a karst cavity located in the west bank of the Sella river and developed in the Carboniferous limestone of the Asturian Massif of the Cantabrian Range (northern Iberian Peninsula). This cave contains an important sedimentary, archaeological and palaeontological record of the Upper Pleistocene and Early Holocene with abundant technological remains (lithic and bone industries) and bone remains of mammals and others vertebrates. The archaeological record starts with a probably Middle Palaeolithic level, followed by a complete sequence of the Upper Paleolithic, with a Lower Magdalenian level clearly identified and dated, and ends with levels of the Late Upper Magdalenian/Azilian and the Mesolithic forming three shell middens. The stratigraphic sequence consists of fourteen levels grouped in two litostratigraphic units with very different sedimentary characteristics studied by geoarchaeological methods. The lower unit is characterized by the significant presence of siliceous sands and silts while the upper unit is formed by three anthropic shell middens cemented by carbonates. This paper analyzes the lithostratigraphic sequence and shows the results of the granulometric, mineralogical, edaphic and radiometric analysis. These results allows us to interpret precisely the lithostratigraphy of the deposits and the sedimentary and diagenetic processes responsible for their formation and evolution. In addition, the radiocarbon dates obtained allow us to place the upper levels of the clastic sequence in the GS 2b and the lower shell midden in GI 1 and GS 1 at the end of the Upper Pleistocene, while the upper shell midden would be located in the Boreal cronozona in the Early Holocene.