During this project, 7446 charcoals and 117 wood samples have been determined using a predetermined methodology that we used before (Joly et al. 2017). Charcoals were cut with a scalpel to observe 3 plans. For the wood, it was boiled to soften and cut to prepare thin cut. They were identified using a microscope (BX53) and a binocular microscope. To compare their anatomy, we used the collection of references created before this project that was supplemented with new references from our fieldwork in Chile and thanks to the new collaboration with archaeologists working in Peru and Argentina (fig.1). We also used different Atlas of wood anatomy. About 35 different taxa were identified, most of them are native.
From these identified wood and charcoal, 147 samples have been selected. Using established protocols, isotope analysis of charcoal (δ13Cchar) and wood samples (δ13Cwood) were realised. The δ13C value is related to climatic variables that affect plant water availability, (Evapotranspiration and precipitation) and could serve as a direct proxy for rainfall variation, and/or water provenance. The results show a difference between the different period, locations and species with a better water availability at the end of Pleistocene.