An ice field on Baffin Island. Vegetation on the edge of the retreating ice here dated back more than 40,000 years, at the limit of age that radiocarbon dating can determine. Researchers sampled 124 plants at 30 locations, finding newly uncovered landscapes at least 40,000 years (and likely up to 120,000 years) old at all of them.
"We found these locations everywhere," Pendleton said. "It's not just one particular elevation or one particular type of ice cap."