How soil can tell stories of the past
At the base of Monticello Mountain, just below Thomas Jefferson's historic estate in Charlottesville, Va., sits a 90-meter-long greenstone wall. The Rivanna River runs on one side. On the other, earth has piled up to the wall's top. Built up from sediments washing down the mountain for centuries, this soil holds clues to history. But rather than bits of tools or pottery, the clues are chemical elements in the soil.