Queen's discovery sheds new light on ancient te...( A new discovery by a team of Queen's Un...)

Queen's researchers have discovered the mineral ikaite in 700-million-year-old marine sedimentary rocks in the Mackenzie Mountains of the Northwest Territories and eastern Yukon. This discovery proves that the ancient ocean was much colder than previously believed, says Noel James of Queen's department of Geological Sciences and Geological Engineering. It has caused scientists to rethink what they know about the temperatures of ancient earth and possible atmospheric conditions at the time.

"One of the main thrusts of our research is trying to unravel the ancient history of the planet," says James. "If we understand what has happened in the past and how the earth has responded and recovered, it will give us some idea of how the world will respond to some of the things that are happening to it now."

The researchers discovered ikaite at several different levels in what were believed to be rock formations deposited in shallow, warm oceans during the interval between two ice ages that extended all the way to the equator millions of years ago. But ikaite forms in shallow water on the sea bottom at cold temperatures and melts when brought to the surface. The fundamental question for scientists is what triggered the enormous ice ages that left the oceans cold enough for the formation of this mineral?

One controversial theory known as "The Snowball Earth" hypothesis suggests that around 700 million years ago the earth was almost totally enclosed in ice. The Queen's discovery offers alternatives to this hypothesis. Glaciers wax and wane according to how the earth's orbit changes relative to the sun and how much solar radiation reaches the earth over a given time, says James. Was there a major celestial change that allowed the oceans to bec
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Contact: Lorinda Peterson
petersn@post.queensu.ca
613-533-3234
Queen's University
10-Jan-2005