The caldera has been active for the last eight million years and eruptions have created several ignimbrites. A recent eruption occurred 73,000 years ago and formed the Campo de la Piedra Pómez ignimbrite layer. About 2,300 ± 160 BCE, the largest volcanic eruption of the Central Andes with a VEI 7 occurred at Cerro Blanco, forming the most recent caldera as well as thick ignimbrite layers. Over of tephra were erupted then. The volcano is dormant since then with some deformation and geothermal activity. A major future eruption would put local communities to the south at risk.