By contrast, continental crust lives to a ripe old age, with some of the oldest continental crust on Earth – dating to 4bn years – found in Canada and Greenland. But geologists have long been puzzled as to why there isn’t more continental crust bobbing around. Mauritius is a young volcanic island which emerged around 9m years ago. Last year, geologist Lewis Ashwal from the University of Witwatersrand in South Africa, discovered tiny zircon crystals hiding within Mauritian volcanic rocks, and these crystals turned out to be 3bn years old. Meanwhile, it isn’t just ancient continental crust that we have trouble keeping track of.

Source: The Guardian March 05, 2017 21:22 UTC