buried soil

Soils comprise adjacent earthy layers of different texture, structure, color, or composition, these layers called horizons. Buried soil, or paleosol, is the horizon of ancient land surface preserved beneath ash, sand, peat, or other deposits, remaining remarkably stable over tens of thousands of years. In many parts of North America, buried soil marks the surface that existed before the advent of agriculture as introduced by Europeans—it was buried by a flood of sediment that eroded from those early mismanaged fields. Buried soil is often analyzed for information about human activity in a given period, or the state of the environment at that time. For instance, a recent excavation project in Richmond, Virginia, called Cactus Hill uncovered evidence in buried soil that suggested to some that Clovis people (thought to have crossed the Bering Land Bridge 13,500 years ago) were not the first to migrate to the Americas. Scientists analyzed two sediments in this ancient sand dune. In the paleosol they found chipping stone implements, burned bone, and campfire remains—evidence, they believe, that confirms human occupation dating back nearly 18,000 years. Buried soil opens the door and offers tokens to explore former knowledge.

Elizabeth Cox