http://www.newsweek.com/snowball-earth-theory-ice-age-geology-glaciers-ancient-earth-971149

A recent analysis found evidence to support the idea of a rapid planetary freeze, suggesting that around 717 million years ago Earth transitioned into a deep freeze in only a matter of a few thousand years, which is surprisingly fast in geological terms.

The study, published online in Geology this spring, is an analysis of rock sequences unearthed in Ethiopia. The rocks called "diamicities" could only have been formed by glacial activity as a result of boulders that would have been transported by glaciers. They also formed with some aid from microbial marine organisms. This combination means that the rocks formed in a cold setting that was warm not much earlier, suggesting that ancient Ethiopia went from a warm climate to an ice climate with little to no time in between, Science Mag reported. Scientists suggest this freeze could have taken between 1,000 and 100,000 years, from start to finish.