The potential impact of the Río Negro Valley on the Late Pleistocene peopling of Patagonia

Abstract

In this paper the potencial importance of the río Negro valley on the peopling of Patagonia is discussed. Flowing along the Pampean-Patagonian border, the Río Negro drains Andean meltwaters across the Southern Cone before emptying into the Atlantic Ocean. This valley is a prominent landscape feature which likely played a role in the peopling of southern South America for several reasons. First, the Río Negro is the largest river in southern South America, flows from mountain to coast, and therefore would require migratory groups bound for Patagonia to locate a feasible crossing before proceeding southwards. Second, as a thoroughfare (Nacuzzi 1998), this waterway provides a direct west to east route allowing access to a wide diversity of environments. Third, as a border region, this valley is an ecotone which offers a wide diversity of natural resources for subsistence. Finally, recent field investigations indicate that during the Late Quaternary, the Río Negro Valley underwent dynamic landscape change