ABSTRACT
The La Plata Basin is a large and little explored river system that, together with the adjacent littoral Atlantic region, is beginning to reveal an early and long sequence of unique and elaborate cultural trajectories. The southern grasslands of South America also have been long perceived as inimical to exploitation by early farmers lacking steel plow technology. This may be true for a large portion of the Pampas; however, a more nuanced view of the different environments encompassing the La Plata Basin indicates that the practices of flood-recessional farming in the vast expanses of wetlands and slash-and-burn along the major river forest corridors must have played major roles in early food-producing economies in the region. The adoption of a mixed economy is paralleled by the appearance at the Los Ajos site of plant grinding tools consisting of milling stone bases and manos in conjunction with a gradual change in the chipped stone technology towards a more generalized and expedient technology.
