Volcano stratigraphy and physical characterization of the San Mateo Pomez Unit, Cerritos Member: Temascalcingo Volcano, Central Mexico

The Temascalcingo volcano is a dacitic stratovolcano located at the eastern part of the Acambay graben, a tectonic basin in the central sector of the Trans-Mexican Volcanic Belt (TMVB), which is an active, mostly calc-alkaline volcanic arc that crosses Mexico from the Pacific Ocean to the Gulf of Mexico. This study characterises the explosive activity of the San Mateo Pumice eruption that is the most recent and largest paroxysmal episode of this volcano and the last unit of the Cerritos Member. Indeed, this eruption is associated with an undated debris avalanche event consisting of a major sector collapse developed on the western flank of the volcano. Stratigraphic data suggest a highly explosive eruption that generated a relatively thick (up to 10 m) and widespread pumice fallout deposit, trending to the NE, and an aerial distribution of at least 100 km2. This subplinian type eruption of VEI 4 lasted about 9 h and produced a plume height up to 12 km above the vent (i.e., ~14 km above sea level). This type of explosive eruption is relatively common in the TMVB, so a comprehensive geological study, with the corresponding numerical simulations like the one that was carried out, contributes to the understanding of the explosive volcanism of modest size stratovolcanoes that are common in the TMVB.