Cerro El Sombrero, Argentina: Fractured Stones on a Flat Hilltop

WEITZEL, CELESTE ; NORA FLEGENHEIMER

Current Research in the Pleistocene

Peopling of the Americas

Lugar: Texas; Año: 2007 p. 68 - 70

8755-898X

Cerro El Sombrero Cima, a 12,000 m2 hilltop site in a quartzite outcrop in the Argentine Pampas, stands out as a unique site among other early Pampean sites due to its dimensions and large lithic collection recovered from stratigraphic excavations and its surface. The assemblage includes a variety of tool types, among which the most diagnostic are fishtail projectile points . At this hilltop site, which must have served as an important panoramic viewpoint, the final stages of the lithic manufacturing process were completed. Therefore, the hilltop has been interpreted as a re-tooling site due to its high breakage index This interpretation is sustained by the numerous signs of knapping errors, for example perverse fractures and use related fractures on a high proportion of projectile point stems. We here report on a current project dedicated to the analysis of causes of fracture of lithic artifacts recovered at the site. The lithic assemblage from Cerro El Sombrero consists of 1631 flaked tools.The breakage index is particularly high with 93% of the studied flaked tool assemblage being fractured and we still have not identified all of the causes that account for the entire broken sample. We assume that if post depositional processes such as trampling were involved, these would be more noticeable in the surface remains. Hence, in order to assess the possible impact of post depositional processes we here compare the fracture percentage differences between the surface and excavated assemblages. Still, we cannot account for the processes involved in the production of most of the fractures in the site but exhaustive analysis of these samples has only recently started. These processes are probably related on one hand to choices concerning the manufacturing, use and discard of tools among these early hunter-gatherers, and on the other to the choice of this landmark as a place where specific activities were carried out and worn-out tools came to be discarded.