PALEONVIRONMENTAL RECONSTRUCTION AND HUMAN COLONIZATION AT PASO OTERO 5 SITE. IMPLICATIONS FOR THE PAMPEAN REGION (ARGENTINA)

Among the early archaeological sites recently recorded in the Pampean Region, Paso Otero 5 (Buenos Aires Province) has yielded a significant archaeological context dated between 10,000 to 10,400 BP. The faunal assemblage, associated with "fish-tail" projectile points, contained large quantities of burnt bones of megamammals. The extinct fauna were assigned to Megatherium americanum, Equus neogeous, Macrauchenia patagonica, Toxodon sp., Glossotherium sp., Hemiauchenia sp., and Glyptodon sp.

The aim of this paper is to know the paleoecological conditions that characterize the Pleistocene-Holocene transition in the study area during the human arrival. Moreover, this paper will attempt to compare these results with the paleoecological information available for the region. In order to achieve this goal a detailed study of the stratigraphic sequence of the site was carried out. In this sense, the results of the analyses of sediment composition, pollen, silicobioliths, diatoms, stable isotopes, sediment organic matter, etc. were combined with the information provided by the archaeological record. As a trend, the different lines of evidence suggest that previous to the human arrival at the site (pre-10,400 BP) the dominated climatic conditions were arid, with a cold pulsation as it is indicated by the pollen and the silicobioliths records. Although less intense, these conditions would have continued until the early Holocene (ca. 8,000 BP). Even though minor discrepancies exist, this general pattern has also been recognized by diverse authors working with different spatial scales of analysis and evidences in other areas of the region.