Activity in the southernmost volcano has been dated at 280,000±22,000 years ago. The complex is linked to the eruption of the Tres Cruces ignimbrite 67,000 years ago, also known as Pampa Blanca. This ignimbrite is well exposed in the valley which separates the Tres Cruces and Ojos del Salado volcanoes, assuming thicknesses of with a basal flow thick. There is evidence for three large glaciations on the mountain, the middle of which predates the Eemian warm period.