Australia: The Land Where Time Began

A biography of the Australian continent 

The Cryogenian Period 850-630 Ma

The Cryogenian is approximately the period of "Snowball Earth",

The Cryogenian is comprised of at least 2 glacial periods, that were previously believed to be a single glaciation, the Varanger, but have since been divided into the Sturtian Glaciation, about 750-700 Ma, and the Marinoan/Varanger Glaciation, about 700-635 Ma. More recent evidence suggests there may have been as many as 4 glacial periods during the Cryogenian. There is also recent evidence challenging the existence of a "Snowball Earth" time when the entire Earth was glaciated.

Sources & Further reading

1. Cryogenian

Links

1. New Evidence Supports Three Major Glaciation Events in the Distant Past
2. Re-Os geochronology of post glacial black shales in Australia: Constraints on the timing of "Sturtian" glaciation