Between 1,150,000 ± 300,000 and 550,000 ± 100,000, the Tocomar ignimbrite was emplaced in the area. It consists of several different units of pyroclastic material, which cover a surface of about . It is likely that geothermal activity was occurring at Tocomar prior to the emplacement of these ignimbrites; geothermally altered material was ejected during the eruptions.