Lake-Bottom Bounty: Some Arctic sediments didn't erode during recent ice ages

The kilometers-thick ice sheets that smothered northeastern Canada and scoured the landscape there during recent ice ages left sediments intact in some locales. This surprising finding could prove a boon to climate researchers.

Most scientists have assumed that the ice sheets that form during ice ages scrape the land clean as they plow across the terrain. Indeed, most of the soil in previously ice-covered arctic areas either formed there since the most recent ice age ended, about 10,000 years ago, or was carried there by wind after the ice sheet disappeared, says Jason P. Briner, a geologist at the State University of New York at Buffalo.