Researchers from the United States and Australia have discovered previously unrecognized structural lines 100 miles or more down in the Earth that appear to signal the locations of giant deposits of copper , lead, and zinc. The metals, however, lie close enough to the surface to be mined, but too far down to be found using current exploration methods. In a paper published in the journal Nature Geoscience, scientists at Harvard University, Columbia University, Geoscience Australia and the Australian National University say this discovery could greatly narrow down search areas, and reduce the footprint of future mines. In detail, the study found that 85% of all known base metal deposits hosted in sediments —and 100% of all deposits that hold more than 10 million tonnes of metal— lie above deeply buried lines girdling the planet that mark the edges of ancient continents. The deposits lie along boundaries where the […]