BBC News
It’s an unassuming rock, greenish in colour, and just over 4cm in its longest dimension. And yet this little piece of sandstone holds important clues to all our futures.
It was recovered from muds in the deep ocean, far off the coast of modern-day West Antarctica.
The scientists who found it say it shouldn’t really have been there.
It’s what’s called a dropstone, a piece of ice-rafted debris.
It was scraped off the White Continent by a glacier, carried a certain distance in this flowing ice, and then exported and discarded offshore by an iceberg. […]
“In our view of observations of that material, it would not withstand a great deal of transport, with deposition and then re-transport over multiple steps of a cycle. And, furthermore, it probably would not hold up well to a great deal of interaction between the ice sheet and the bedrock. It would be destroyed and disaggregated,” Christine Siddoway, professor of geology at Colorado College, US, told BBC News. […]
“Our findings do confirm that the ice sheet can disappear fairly rapidly and also that it can re-establish itself fairly readily,” explained Prof Siddoway.