image: Half Dome, one of the most ionic peaks in the Yosemite National Park, Calif., USA. Modern continents are largely made up of light colored rocks, similar to those found in the Yosemite National Park. A new study shows that these rocks dominated Earth's emerged lands since at least 3,500 million years ago. This material relates to a paper that appeared in the Sept. 22, 2017, issue of Science, published by AAAS. The paper, by N.D. Greber at University of Chicago in Chicago, Ill., and colleagues was titled, "Titanium isotopic evidence for felsic crust and plate tectonics 3.5 billion years ago." view more
Credit: © Basil Greber