1. Instituto Geofísico, Escuela Politécnica Nacional, A.P. 17-01-2759, Quito, Ecuador;2. IRD, UMR 163 Laboratoire “Magmas et Volcans”, A.P. 17-01-2759, Instituto Geofísico, Quito, Ecuador
Abstract:
Ice-capped Chimborazo is one of the large composite Ecuadorian volcanoes whose recent eruptive activity is poorly known. This paper presents the characteristics and the ages of a newly discovered Holocene sequence of pyroclastic deposits on the east and north sides of the cone. Lying upon a moraine of the Late-Glacial period, the most complete section of ~ 4.5 m in thickness is located 5 km from the present summit crater. It consists of seven massive or diffusely stratified ash flow layers and four fallout layers interbedded with seven paleosoils.