El Misti medium-high-K calk-alkaline suite range from andesites to rhyolites (SiO2 57-74 wt.%). Trace elements and isotope ratios (87Sr/86Sr, 143Nd/144Nd) indicate crustal contamination-assimilation processes particularly between 38 and 11 ka. Geochemical modelling shows that AFC has controlled the petrogenetic evolution. The amount of assimilated crust from the Proterozoic basement does not exceed 14 wt.%. The source of the parental magmas point to a mantle wedge peridotite modified by adakitic melts.