Timeline from 30,000,000 BP to 600,000 BP

6,000,000 BP: in Heise Volcanic Zone, a very large volcanic eruption occurred at the Yellowstone hotspot in Idaho, U.S. Ejecta bulk volume of about 1,500 km3. Blacktail tuff noted.

5,700,000 BP: at Altiplano-Puna volcanic complex at Cerro Guacha, Bolivia a very large volcanic eruption occurred. Ejecta volume of about 1,300 km3. Guacha ignimbrite and two smaller eruptions identified.