In an article by Neil Bowdler on BBC.co.uk, Bowdler discusses the possibility of the 'snowball Earth hypothesis.' It is believed that 700 million years ago in the cryogenic age, an ice age occurred. Recent evidence shows that there may have been small turbulent oceans that allowed micro organisms to survive such harsh conditions. Deposits of sediment in Australia has been found by researchers that they say suggest turbulent oceans existed there millions of years ago. They have also found a particular kind of bed rock called hummocky cross bedding that they say can only exist where storm waves would have been. The waves that push sand along the ocean of the floor eventually make a type of sand stone. This sandstone has pockets between them which would be a prime location for these microorganisms to survive. Many people speculate this idea with their own belief that the earth was more of a "slush ball," which would better explain how organisms could survive frigid temperatures.

http://www.bbc.co.uk/news/science-environment-11992299