Variations in human ecodynamics in the southern Pyrenees: chert procurement and use at Cova Gran de Santa Linya during the Upper Paleolithic

Abstract

The southern slope of the Pyrenees is rich in siliceous resources, particularly chert. This material, widely distributed across the region, was the primary raw material exploited by anatomically modern humans (AMH) during the Upper Paleolithic. However, it remains unclear whether the procurement strategies employed during this period—marked by multiple climatic fluctuations and chrono-cultural phases remained consistent or changed over time. To address this question, an archaeopetrological characterization of chert was conducted on the core and retouched tool assemblages from the Upper Paleolithic sequence at Cova Gran de Santa Linya. This analysis aims to identify the sedimentary origins of the silicifications and infer potential procurement zones to detect variations in lithic organization and procurement strategies over time. The study distinguishes two main types of silicifications: cherts formed in a continental hypersaline (evaporitic) sedimentary environment, likely associated with the Garumnian facies of the Tremp Formation, and cherts derived from a continental lacustrine environment, available in various geological formations within the Pre-Pyrenean Marginal Ranges and the Ebro Valley. Additionally, marine-origin cherts were identified, in formations located both on the southern and northern foothills of the Pyrenees. This preliminary approach suggests a primary procurement strategy in the transverse valleys of the southern Pyrenees and the Ebro Depression. The presence of marine-origin cherts, whose outcrops are located at a greater distance, suggests a certain permeability towards northern territories within the Pyrenean range. Furthermore, we detected a shift in raw material use and management throughout the Upper Paleolithic, particularly from the Last Glacial Maximum (LGM) onwards, where evaporitic chert varieties decrease in favor of lacustrine varieties. This progressive changes in raw material use coincides with parallel re-organisation of technology during the Magdalenian. Long-distance tracers are mainly identified on the onset of the LGM, likely indicating broader mobility and procurement strategies as a resilient response to harsh climate conditions and resources availability.