30 Mya to 25 Mya
28.1 Mya, Paleogene, Oligocene Chatian: Ancestor of apes and humans. Grande Coupure extinctinction. Start of widespread Antarctic glaciation. Rapid evolution and diversification of fauna, especially mammals.
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27,000,000 BP, USA: A volcanic eruption at what is now La Garita Caldera site of the San Juan volcanic field in Colorado. Approximate ejecta bulk volume: 5,000 km cubed.
~ USA: The Laramide Revolution shook the Earth. It raised the US state of New Mexico above sea level and began a period of Volcanism.
25,000,000 BP, USA: In the Laramide Revolution the land of what is now New Mexico was raised above sea-level and began a period of volcanism
