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Site content related to keyword: "amphibolites"

Geologic History of the Delaware Piedmont

Fig A. Cross section of eastern North America as it may have looked 543 million years ago, active volcano is offshore.

The Delaware Piedmont is but a small part of the Appalachian Mountain system that extends from Georgia to Newfoundland. This mountain system is the result of tectonic activity that took place during the Paleozoic era, between 543 and 245 million years ago. Since that time, the mountains have been continuously eroding, and their deep roots slowly rising in compensation as the overlying rocks are removed. It is surprising to find that although the Delaware Piedmont has passed through the whole series of tectonic events that formed the Appalachians, the mineralogy and structures preserved in Delaware were formed by the early event that occurred between 470 and 440 million years ago, called the Taconic orogeny.

What are GeoAdventures?

The Wilmington Western Railroad follows the Red Clay Valley through the Delaware Piedmont cutting through many of the Piedmont rock units.

GeoAdventures are designed to allow the reader to learn about a particular geologic point of interest in Delaware’s Piedmont province and then take a short field trip to that area. Want to know more about the Wilmington blue rock or Brandywine blue granite? Take the Wilmington Blue Rock GeoAdventure and go see just what the blue rock looks like.