Spatial–temporal distribution of explosive volcanism in the 25–28°S segment of the Andean Central Volcanic Zone

Abstract The present contribution describes and analyses the spatial–temporal distribution and main features of the volcanic rocks, with emphasis in pyroclastic deposits, located in the 25–28°S segment of the Central Andes. We built a new database, based on our own field studies and compilation from the literature, where we discriminate the different pyroclastic units. We find that the pyroclastic deposits cover an area of at least 7770 km 2 and are distributed mainly along N–S to NNE–SSW, NW–SE to WNW–ESE and NE–SW trends. The spatial distribution of these deposits has varied with time: those > 14.5 Ma are concentrated west of 69°W; during 14.5–11.5 Ma explosive magmatism shifted east of 67°W; the deposits Moreover, we find that a) basement lithology or composition or mechanical features influenced distribution of volcanic activity; b) the NE–SW alignment of