Aguas Calientes caldera erupted twice dacitic ignimbrites. was the source of two major ignimbrites; the Tajamar Ignimbrite (including the Chorrillos Ignimbrite inside the caldera), and the Verde Ignimbrite. The first was erupted 10.5-10.1 Ma and is a body of ignimbrite of about . The second was erupted 17.2 Ma and has a volume of . The Abra de Gallo ignimbrite was formerly considered the third and erupted 10.0-10.5 Ma; Petrinovic et al. consider it part of the Tajamar ignimbrite. Both eruptions probably resulted from a disruption of the magma chamber integrity by vertical faults created through the activity of horizontal fault systems in the region. There is no evidence of plinian eruption columns in the eruption deposits and the chemistry of the deposits indicates they originated in a homogeneous magma chamber.