The layering of one soil deposit upon another is called stratigraphy. Think of stratigraphy as layers of a cake with filling and icing. Generally, in nature the oldest soils and materials are in the lowest layers. The newest soils are the layers closest to the earth’s surface. This is the Law of Superposition. This important principal helps archaeologists date the objects and features they find.

Study the stratigraphy in this site. Run your mouse over the layers and objects to learn more. Can you guess which layer is the oldest? Can you tell when the refuse pit and hearth were used? What can we learn from the artifacts? What kinds of artifacts might not survive in the ground? Can you date any of the artifacts? Which layer would contain material from your house? Which layer might contain material from your great-grandparents?