Science Daily May 7, 2020
The Great Unconformity, as it is known, accounts for more than one billion years of missing rock in certain places. Scientists have developed several hypotheses to explain how, and when, this staggering amount of material may have been eroded. Using the ratio of helium to thorium and uranium in certain minerals as a paleo-thermometer a team of researchers in the US (University of Colorado, UC Santa Barbara) tracked how rock moved in the crust as it was buried and eroded through the ages. They extracted grains of a particularly resilient mineral, zircon, from the stone and analyzed the radio nucleotides of helium contained inside which revealed that several kilometers of rock had been eroded from above this granite between 1,000 and 720 million years ago. The basic hypothesis is that this large-scale erosion was driven by the formation and separation of supercontinents…read more. TECHNICAL ARTICLE
Grand Canyon (stock image). Credit: © SeanPavonePhoto / Adobe Stock