The results of morphometric and technical analyses of 103 small stemmed projectile points from the north of Chubut province (Patagonia, Argentina) are presented. These artifacts were collected in three ecologically differentiated but adjacent environments: the maritime coast, the middle and the lower valley of the Chubut River, and the northern-central plateau. The specimens were obtained during archaeological research and from a private collection. The goal of this research is to identify trends and to explore their relationship with technological-based decisions and the circulation of raw materials, objects, designs, and information among different groups. Although highly intra and interarea morphological diversity is recorded, three subtypes predominate: straight or slightly convex triangular edges, stems with straight edges and concave bases. Two of these subtypes have not yet been identified in the archaeological literature from other parts of Patagonia. Statistical analyses – ANOVA and PCA, carried out on the metric attributes of the stem, did not show significant differences. Chalcedony, obsidian, and fossilized wood from spatially circumscribed sources were proven to be the most frequent raw materials among the three areas, supporting different models of intensification of exchanges in central and northern Patagonia by the end of late Holocene.

The coast of the Río Negro province presents hunter-gatherer-fisher occupations dated from the Middle to the Late Holocene, a period in which the utilization of marine and terrestrial resources is recorded, as well as the manufacturing of a wide variety of lithic artifacts using mainly four types of rocks. In previous papers, we studied the use of lithic raw materials at a regional level, comparing different areas of the San Matías Gulf. In this paper, the scale of analysis focuses on six specific archaeological localities, which are dated through the entire human occupation of the area. The aim is to analyze changes over time within each set of lithic materials, and to determine if the scales continue to show the regional trends established in previous papers. Technological and raw material analyses were performed, and statistical methods were applied to establish general trends in the samples. The results indicate that, unlike previous studies, the type of rocks that were used varied over time, and that several of the studied localities also show significant variations in the other indicators that were analyzed (cortex percentage, broken vs. unbroken artifacts, among others).