As for the pollen, Sugden says it has never been accurately dated and may come from a much earlier clement period.
至于花粉，萨格登说从未有人精确地测定过它的年代，也许它是源于更早的温和时期。
2
Sugden, a geologist at the University of Edinburgh, was trying to date an ancient volcanic eruption in East Antarctica when he and his colleague uncovered the old ice.