Spatial and temporal variability in the use of lithic raw materials for flaked stone technology in northeast Chubut Province (North Patagonia) during the Late Holocene

This work presents and discusses the results of the presence of changes in the selection and use of raw materials for flaked stone during the Late Holocene in two areas of northeast Chubut Province: the north coast and the lower valley of the Chubut river (VIRCH). We considered two temporal blocks: 3000–1200 BP, and 1100–400 BP. Three hypotheses were tested: (1) in both areas, there was an overriding exploitation of locally available rocks; (2) rock exploitation was more diversified in VIRCH; and (3) there was an increase in raw materials of extra-regional origin post 1000 BP. Rock sampling aimed at characterizing the regional lithic resource base, and the results of the lithological classification of fourteen lithic sets made it possible to verify the predominant presence of artifacts made of local rocks, including silex and basalt, in both areas and both temporal blocks, and an increment in the record of artifacts made of chalcedony in the second temporal block. At a macro-regional level, the observed temporal tendencies point to similarities and differences with respect to models formulated for the northern and central coast of Patagonia.