Exploitation of lithic raw materials and occupation of space along the middle and late holocene in the west coast of San Matías gulf (Río negro, Argentina)

Abstract

The archaeological occupation of the San Matías Gulf coast (Río Negro province, Argentina) began at 6000 to 450 years BP. In particular, the oldest occupations in the west coast of the gulf are dated around 3000 years BP. From this moment on, the hunter-gatherers who inhabited the area exploited several types of lithic raw materials, in order to manufacture artifacts for different purposes. In this paper we present the techno-morphological characteristics of the lithic assemblages recovered in the study area, the lithic raw material analysis of the sample and the results of the reduction intensity for different types of rocks. To establish if the rocks use changed over time, we split the artifact sample into two chronological blocks defined for the area. The results indicate that a large variability of rocks, mainly of local origin, was used in this portion of the Rio Negro coast, and that some particular raw materials, like obsidian, were transported from distant sources. The rocks that would have been more used were chalcedony, flint and acid volcanics rocks, along with jasper in the earlier moments of the occupation, and chert in the later ones.