Comprehensive use of the geological resources of the Cañadón Asfalto Basin by ancient hunter-gatherers of the middle Chubut River valley (Argentine Patagonia).

This paper presents the results of an integrated study encompassing archaeological and geological fieldwork, laboratory analysis of materials, and surveys of museums and private collections. These findings demonstrate the widespread use of various geological resources from the Cañadón Asfalto Basin by the indigenous populations that inhabited the current Chubut province in the past. Central-northern Patagonia has been explored for at least 10,000 years by nomadic hunter-gatherers with marked seasonal mobility, who exploited different available environments to supply themselves with lithic raw materials, pigments, food, firewood, and shelter. The evidence obtained through our work—particularly at archaeological sites in the middle Chubut River valley—shows that colored silica, chalcedony, and opals were the raw materials most frequently used to manufacture flaked tools. Meanwhile, basalts or gabbros were selected for making boleadoras or throwing balls, and sandstones were used for grinding stone tools. Ignimbrite outcrops were recurrently chosen as temporary shelters and/or as support for rock art. Among the various colors and materials available regionally for producing paint, red hematite was the most widely used. It is also worth noting that clays, widely available in lagoons and endorheic basins, were used for rock and/or body painting, as well as for manufacturing ceramic pieces for domestic purposes