Episode 96: Measuring Ages and Histories of Rocks in the Earth’s Crust and Beyond
When and how fast do mountains form and erode away? What lies beneath miles of ice in Antarctica? Could life on Earth have arrived from other planets? Peter Reiners uses radioisotope dating to probe the thermal histories of rocks, both from Earth and meteorites, to answer a wide range of such questions. His group has focused on the use of the uranium-thorium/helium method to determine when rocks cooled, how sediment moves, and how paleofluids flowed deep beneath the surface. In Antarctica, they deduced that the major mountain ranges and canyons beneath the ice were carved in a short interval of time about 34 million years ago. Using the method on Martian meteorites, they have shown that the impacts that ejected the rocks from Mars produced high temperatures that probably would have destroyed complex organic molecules before they reached Earth. In this episode: Peter Reiners, PhD, Professor and Head, UA Department of Geosciences; Leslie P. Tolbert, PhD, Regents’ Professor in Neuroscience