Geology

Travel back to when the Chesapeake Bay was first formed to learn about the geologic history of the region.

An eroding cliffside shows layers of sediment that have accumulated over time.
An eroding cliffside at Maryland's Calvert Cliffs reveals layers of sediment that have built up over time. (National Park Service)

For thousands of years, the Chesapeake Bay has been changing continuously. Some changes are sudden, whereas others take place over such a long period of time that we can only see them by looking back into geologic history. All geologic changes affect the Bay ecosystem, for better or worse.