Microfossils for assessing the use as projectile points or knifes of archaeological artefacts from Quebrada Seca 3 site, Southern Argentinean Puna (ca. 5000-4500 years BP)

BABOT, PILAR; HOCSMAN, SALOMON; CATTÁNEO G. R

MAR DEL PLATA, BS. AS. ARGENTINA

Workshop; 7th International Meeting on Phytolith Research (7IMPR); 2008

Several lithic artefacts from hunter-gatherer occupations of Quebrada Seca 3 site (Antofagasta de la Sierra, Southern Argentinean Puna, between ca. 5000-4700 years BP), are analyzed. These stone tools have recently been defined as stemmed projectile points were the limbs were intensively maintained resulting in asymmetric shapes (Hocsman 2006). Previously, it was proposed the use of these artefacts as knifes because their morphology when the artefacts where discarded (Aschero 1988, Aschero et al. 1991). Trying to establish a more complete version of the life history of these artefacts, from projectile points to knifes, as it was suggested by techno-typological analysis, we are developing a research design that includes several analytical microscopic techniques to identify the preserved uses. Preliminary information obtained through microwear use analysis and compositional study of macroscopic residues in limbs and stems, indicates the processing of plant material and the use of plant adhesives for hafting. In this paper, we present the results obtained from the microfossil record sampled from active edges and stems to complement and cross-checking previous data. Microfossil analysis of lithic projectile points/knifes from Quebrada Seca 3 site showed the processing of plant material with asymmetric limbs (4 cases).The plant material recorded includes: tuberous/root starch grains (some of them aff. Oxalis tuberosa), silicaphytoliths and epidermal tissue (charred or dehydrated) and non identified phytoliths and particles.The above mentioned appears to be a rather specific function for the “knife use” of artifacts taking into account the varied microfossil record on contemporary grinding tools from Antofagasta de la Sierra.Use-wear analysis showed the presence of micropolishes due to bone and plant working.Only 4 artifacts contained microfossil on their limbs, but several artifacts had micropolishes due to plant working. Various artifacts had plant and animal use wear and a few artifacts had not preserved residues and use wear.The results obtained proved the use of lithic artifacts on plant and animal materials, the first one being uncompatible with the assumed projectile point function. Stem analysis showed the presence of adhesives for hafting (plant gums, according to Infrarred analysis). Adhesives may or not contain several kind of calcium crystals and charcoal particles.