CONICET | Buscador de Institutos y Recursos Humanos

The aim of this work is to integrate archaeological, geoarchaeological, chronological, and paleoecological information in relation to human occupations in semi-arid environments of the inland Pampas during the Early Holocene. We present the analysis of several lines of evidence (paleoclimatic reconstructions, geology, faunal and techno-morphological studies) obtained through a paleoecological perspective conducted in the Laguna Cabeza de Buey 2 site (San Carlos de Bolívar District, Buenos Aires province, Argentina). This site is localized on the eastern border of the aeolian unit called Central Pampean Dunefield, which is characterized on the basis of its geomorphological features and the geological and structural settings. The main landforms are linear dunes, 100-130 km long and 2-3 km wide, with a general N-NE trend and a relative relief of around 2 m. Dune orientations suggest paleowinds from the SW quadrant during the Pleistocene. Pollen records indicate subhumid-humid climatic conditions at beginning of the Early Holocene in this area and changing towards slightly drier conditions between 9000 and 7000 years C14 BP. This dry phase is also suggested by faunal records and isotopic analyses. The Cabeza de Buey 2 site is represented by four human occupation events, starting in the stratigraphic Unit IV associated with the Early Holocene (ca. 7000 years C14 BP). The textural studies carried out in the Unit IV suggest a loamy sand deposit with the presence of subordinated carbonates. The faunal assemblage is integrated by skeletal remains of the ungulates Lama guanicoe and Ozotoceros bezoarticus, an extinct mega-mammal (Toxodon sp.), and some small mammals species such as armadillo (e.g., Chaetophractus villosus, Zaedyus pichiy, and Tolypeutes matacus) and rodents (Ctenomys sp., Akodon sp., and Reithrodon sp.). Among the identified species the camelid Lama guanicoe presents clear evidence of human modifications (e.g., cut marks and burned bones). The habitats required by these taxa suggest the presence of environments with well-drained soils and a relatively homogeneous grassland. In addition, the ecological significance of most vertebrate fauna and the pollen record suggests that this environment was developed under a warm and semi-arid climate. Three types of lithic raw materials were recorded, predominating quartzite (ca. 55%) and chert (ca. 43%), whereas silicified dolomite was found in low frequencies (ca. 2%). All of the materials are non-local stones because they are coming from the Tandilia Hill System, more than 100 km to the east from the site. The techno-morphological analysis suggests that the last stages of the stone tool reduction sequence were carried out in the Cabeza de Buey 2 site, mainly the resharpening of quartzite and chert tools. This site may correspond to a locus of specific activities related to the processing of animals such as Lama guanicoe during the Early Holocene in the Central Pampean Dunefield.