Geologic History of Delaware

The geologic history of Delaware spans over a billion years, beginning with ancient volcanic and sedimentary rocks forming the foundation. During the Paleozoic Era, shallow seas covered the region, creating limestone and shale deposits. In the Mesozoic and Cenozoic periods, seas retreated and advanced, shaping coastal landscapes and depositing sands, clays, and fossil-rich layers. Glacial and erosional processes sculpted the coastline and inland features. Today, Delaware's geology features sedimentary formations, marshlands, and bluffs that reflect its dynamic history of sea-level changes, sediment deposition, and tectonic activity over millions of years.