The Loma Ruiz 1 site: Lithic technological strategies during the Initial Late Holocene in eastern Pampa-Patagonia transition

Abstract

The Loma Ruiz 1 site (Buenos Aires Province) is located in the lower stream of the Colorado river, in the eastern Pampean-Patagonian transition. The archaeological assemblage recovered is composed of lithic, faunal and pottery remains, both in surface and in stratigraphic position. The archaeological component defined in the latter is dated at ca. 1900-1600 14C years BP. The objectives of this paper are to discuss the techno-typological characteristics of the lithic assemblage, the acquisition and management strategies of lithic raw materials, the purposes involved and employed knapping techniques, the débitage and façonnage methods, chaînes opératoires and diversity of tool categories. These results indicate strategies of differential exploitation of particular rocks according to their origin (local, areal and extra-areal). Knapping techniques, débitage methods and tool characteristics, as well as the differences in the space-time fragmentation of the chaînes opératoires related to raw material provenience, revealed differences in planning and tool production strategies. The presence of artifacts made of raw materials from the Humid Pampa sub-region and, possibly, from Northern Patagonia, indicates the circulation of tools in an advanced stage of preparation for the Initial Late Holocene (ca. 3000-1000 years BP). On the basis of these results, the already proposed lithic technological model for the lower stream of the Colorado river is evaluated.