Raw material availability and distribution, and human exploitation strategies in coastal North Patagonia, Río Negro province, Argentina

CARDILLO, MARCELO; ALBERTI, JIMENA

Simposio; 5th Arheoinvest Symposium "Stories Written in Stone" International Symposium on Chert and other Knappable Materials; 2013

The coast of San Matías Gulf (Río Negro province, Patagonia, Argentina) (Figure 1) can be divided into two areas, according to its orientation and the general environmental settings. The northern coast (Figure 1) runs from East to West and it has active cliffs in alternation with bays and abrasion platforms. In this portion of the Gulf there are about 50 archaeological sites, in form of shell middens and lithic scatters on deflated surfaces (Favier Dubois et al. 2008). These sites have been dated to between ca. 6000 and 450 14C year BP (Favier Dubois 2012). The western coast (Figure 1) runs from North to South and has a more regular beach with awide rocky intertidal range (up to 1.5 km). Archaeological information in this sector comes form 30 locations, most of them datedto around 3000 14C year BP (Favier Dubois y Borella 2011).The raw material sources on the northern coast are secondary ones, composed mainly of volcanic rocks with very good and excellent flaking properties. These sources show a continuous distribution. The western coast, on the other hand, has primary andsecondary sources of greater quality, the main type of rocks here being cryptocrystalline. Also there are some sectors in this area with significant primary outcrops of sedimentary and volcanic rocks, with different degrees of silicification. Some of them were probably used in an opportunistic way.We think that these differences affected the lithic resources management strategies (procurement, production, transportation and discard of stone tools). In a regional scale, we have evidence of good quality raw material transport, from areas beyond the Gulf,which are located between 200 and 400 km away (Favier Dubois et al. 2009). Taking into account the distribution and composition of the sites that have been studied, we discuss possible models of exploitation of lithic raw materials. To do that, we use statisticalmethod of spatial analysis and multivariate techniques to detect patterns in the data set.