(360-260 Ma), Andean-Saharan (450-420 Ma), Cryogenian (720-635 Ma) and Huronian (2,400-2,100 Ma).

Within the Quaternary ice age, there were also periodic fluctuations of the total volume of land ice, the sea level, and global temperatures. During the colder episodes (referred to as glacial periods or glacials) large ice sheets at least 4 km thick at their maximum covered