Marinoan Glaciation

The Marinoan glaciation was a period of global ice coverage during the Cryogenian period, dated by a 2025 study to between about 639 and 635 million years ago, roughly 4 million years in duration. Glaciers extended and contracted in rhythmic pulses that may have reached as far as the equator, and the episode is considered a snowball Earth event. It ended when volcanic release of carbon dioxide and the dissolution of clathrate hydrates warmed the planet enough to trigger deglaciation, helping create conditions for new life forms to emerge in the following Ediacaran period. It was named by researchers Douglas Mawson and Reg Sprigg in 1950 after an Adelaide suburb.