ScienceDaily (Apr. 22, 2004)

Excerpt:

Glaciers reached Cape Cod, Massachusetts, in the most recent ice age about 20,000 years ago. But much harsher ice ages hit the Earth in an ancient geological interval known as "the Cryogenian Period" between 750 and 600 million years ago. A team of geologists from China and the United States now report evidence of at least three ice ages during that ancient time.

"The Cryogenian Period is characterized by some of the worst glaciations in earth history. But the available age constraints are so few that geoscientists don't even know how many glaciations occurred in the Cryogenian. Now, we believe we have evidence that there were at least three Cryogenian glaciations, and there may have been more," says Shuhai Xiao of Virginia Tech's Department of Geosciences.

LINK