WASHINGTON, April 18, 2014 (AFP) – US geologists said Thursday they have uncovered a preglacial tundra landscape preserved for 2.7 million years far below the Greenland ice sheet. They then sampled a rare form of the element beryllium, the beryllium-10 isotope formed by cosmic rays.
The research, backed by National Science Foundation funding, found that the soil had been stable and exposed at the surface between 200,000 and a million years before the ice covered it.
The team of scientists also measured nitrogen and carbon that could have been left by plant material in the core sample, and found organic material that suggested that the preglacial landscape may have been a partially forested tundra. Glaciers are known to scrape everything off any given plot of land — vegetation, soil and even the top layer of bedrock — so scientists expressed great surprise that they had found the landscape in pristine condition below two miles (three kilometers) of ice.
The finding provides strong evidence that the ice sheet has existed for much longer than previously known, and survived numerous global warming episodes, according to the lead researcher, University of Vermont geolog