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About 720 to 640 millions years ago, our friendly earth was not so friendly. Its surface was lined with ice due to glaciation that seemed to be eternal. Even though many of its features were unknown, research from a team at the University of Southampton suggests that "explosive underwater volcanoes" were an important factor at this point. It was called the "Snowball explained is the rapid deglaciation of this time, including the formation of "cap carbonate" deposits in warm waters that are almost hundreds of meters thick.

"When the volcanic material is deposited in the oceans it undergoes very rapid and profound chemical alteration that impacts the biogeochemistry of the oceans," Tom Gernon, lead author of the study, said in a press release. "We find that many geological and geochemical phenomena associated with Snowball Earth are consistent with extensive submarine volcanism along shallow mid-ocean ridges."

With Rodinia breaking up, there was the creation of mid-ocean ridges over millions of years. The lava from these volcanoes probably erupted in shallow water, leading to large amounts of hyaloclastite, or the glassy, pyroclastic rocks on the sea floor, which move on to chemical changes in the ocean, such as releasing massive amounts of calcium, magnesium and phosphorous.

"We calculated that, over the course of a Snowball glaciation, this chemical build-up is sufficient to explain the thick cap carbonates formed at the end of the Snowball event," Gernon explained. "This process also helps explain the unusually high oceanic phosphorus levels, thought to be the catalyst for the origin of animal life on Earth."

The findings were published in the Jan. 18 issue of Nature Geoscience.