The soil under the highest point of the Greenland Ice Sheet, scientists have learned, is 2.7 million years old, LiveScience reports. In other words, the silt buried under thousands of feet of ice "has been preserved from beyond the dawn of humankind," says Paul Bierman, who determined the soil's age through a geochemical dating process. The findings also suggest Greenland wasn't always as frosty as it is today: Instead, it was a tundra for between 200,000 and one million years before it was encased in ice. It was once home to bits of forest, the scientists found using offshore plant DNA.
In other words, as the International Business Times has it, "Greenland really was green." The Greenland Ice Sheet that's there now, however, has been remarkably durable: The findings imply that it made it through a strong period of warming some 130,000 years ago. "It's unlikely the ice sheet has disappeared for significant periods of time in the last three million years, at least at this one pinprick on this big island," Bierman says. "Now human activity may spell the end of it." (What else lies under Greenland's ice? A canyon that dwarfs the Grand Canyon, an aquifer holding 100 billion tons of water, and two huge lakes.)