The Proterozoic time period began about 2500 million years ago. Besides many changes in life on the planet, there were other events taking place. Several glaciations took place in the Phanerozoic before the Proterozoic time. Some of the oldest rocks come from Witwatersrand Supergroup of South Africa. These rocks found has four separate glacial-till metamorphosed horizons. They were dating about 2,720 to 2,360 million years, which is the end of the Archean age.

Some younger ranges have been found with sediment from Proterozoic glaciers. A very popular formation is called Gowganda. It was discovered by a Canadian geologist named Arthur Coleman in 1908. Studies done on Gowganda along with other formation findings, geologists believe an icecap might have formed over Lake Superior and southwest of Hudson Bay in the early Proterozoic. Congruent deposits have been located in Michigan, the Medicine Bow Mts. Of Wyoming, and in Quebec, Canada. Deposits of the same age are also present on other continents, for example, Australia and in South Africa. The precision of dating is not definite enough to tell if there was a single, wide glaciation or numerous glaciations at different times at different locations.