Huronian glaciation

The Huronian glaciation (or Makganyene glaciation) lasted from 2400 million years ago (mya) to 2100 mya, during the Paleoproterozoic era. 

The glaciation was named after evidence recovered from the Lake Huron region in North America. There, three separate horizons of glacial deposits are separated by non-glacial sediment.

This was one of the most severe and longest ice ages in geologic history. It was similar to the Snowball Earth ice ages that happened later, in the Neoproterozoic era.  A snowball period, c2.4–c2.0 billion years ago, triggered by the Great Oxygenation Event    

The glaciations were probably triggered by the Great Oxygenation Event (GOE), which removed atmospheric methane (a greenhouse gas), and eventually supplied free oxygen to the atmosphere. The alternate warm and ice age periods was probably caused by a repeating cycle. Cyanobacteria flourished in the warm periods, producing huge amounts of oxygen. The oxygen removed the free methane, and used up carbon dioxide. This caused the temperature to crash. This slowed down the bacteria. So the temperature rose again.

However, it is also possible that there was a 250 million year lull in volcanic activity, resulting in lower carbon dioxide levels and so reduced greenhouse effect.

References

Category:Proterozoic
Category:Extinction events
Category:Ice ages