The elusive case of pampean bifaces. Traditional and fatty acids analyses

NORA FLEGENHEIMER; NATALIA MAZZIA; CELESTE WEITZEL; MARIANO COLOMBO

Simposio; 11th Symposyum on Knappable Materials; 2017

Unifacial tools traditionally characterize lithic assemblages in the Pampean region, bifaces are considered exceptional, except in Late Pleistocene-Early Holocene occupations where they can be frequent. Yet, recent excavations in an orthoquartzite quarry with Middle and Late Holocene dates has produced an important number of bifaces.  We here analyze two groups of bifaces: one from El Picadero quarry, Tandil and the other from early occupations at Cerro El Sombrero and Cerro La China from special purpose and domestic sites. We apply both traditional lithic analysis to understand biface technology and life history, and fatty acids analyses to focus on their uses/functions. As expected, biface sizes differ, with larger and heavier bifaces in the quarries; but contrary to expectations, both samples exhibit evidences of use on organic resources. Based on these analyses the role of these bifaces and practices related to their disposal in relation to site function are considered. Also, their absence in many pampean collections and its possible relation to raw material distribution is discussed.