Geologic Principles and the Eno River - An Overview

To learn about the rocks exposed along the Eno River, we must first learn about the three basic rock types of geology - igneous, metamorphic and sedimentary rocks.  All three of these rock types can be found along the Eno, making it an excellent place to learn about geology!

Click on the rock type to learn more: igneous, metamorphic and sedimentary

The Eno River traverses two different bodies of rock:  the Carolina terrane (formally known as the Carolina slate belt) and the Durham Triassic basin (fig. 4). 

two main rock areas

From its headwaters in northern Orange County to just east of Roxboro Road in Durham, the Eno River flows over the slightly-metamorphosed igneous rocks of the Carolina terrane.  Rocks of the Carolina terrane are approximately 630 million years old and are very resistant to erosion.  You can observe these rocks at Eno River State Park and West Point on the Eno Park.  As the Eno flows east from Roxboro Road and into Falls Lake, it traverses two younger rock types in the Durham Triassic basin: 1) approximately 225 million-year-old sedimentary rocks; and 2) approximately 200 million-year-old igneous rocks called diabase.  The sedimentary rocks are more easily eroded than the resistant diabase that intruded the Triassic basin.

Click on the rock type to learn more: igneous, metamorphic and sedimentary

Learn more about the Geologic Story of the rocks of the Eno River: The Geologic Story