Geology of Delaware

The coastal plain in Delaware is by far the largest province, encompassing all of the state south of the Kirkwood Highway from Newark to Wilmington.

As recently as five million years ago, much of present-day Delaware was submerged as the floor of a shallow sea, the Salisbury Embayment; only with the retreat of global sea levels in recent geologic times did the coastal plain areas of the state emerge as dry land.

[2] The Piedmont Physiographic Region of Delaware only includes the hills of northern New Castle County, which rise to approximately 400 feet (120 m) above sea level.

The cities of Wilmington and Newark lie at the Fall Line, where the northern margin of the younger Cretaceous coastal plain sediments overlie the older Piedmont rocks.

DGS research and service activities are focused on five areas: (1) geology, (2) hydrology, (3) natural hazards, (4) the state geospatial framework, and (5) information dissemination.