In situ EMPA and LA-ICP-MS chemical analysis of mantle xenoliths from Sierra Baguales (50°S), Patagonia

The Patagonia is a vast region located in the southernmost tip of the South America continent. It shows a basaltic plateau formed by volcanic activity started in the Upper Cretaceous-Lower Cenozoic (e.g., Baker et al. 1981; Ramos et al. 1982) and continued during Plio-Quaternary period. Long this time, the basalts have changed their compositions due to a variation in the tectonic environments.

We studied mantle xenoliths hosted in the Plio-Quaternary alkaline basalts from Sierra Baguales, which are related to the back-arc environment (Munoz and Stern 1988, 1989; Munoz et al. 1989). Samples are recognized in two different areas (i) Cerro del Fraile and (ii) Cono Sin Nombre, which are situated to the NW and SE with respect to Sierra Baguales, respectively.