Geological History of the Catskill Mountains

The Catskill Mountains are located in New York state, northwest of New York City. They are often thought to be a part of the Appalachian Mountains but they are not geologically related.

Dissected Plateau

Although the Catskills are considered a series of mountain ranges, they more closely resemble a dissected plateau.This is an area that was raised and than significantly eroded, allowing sharp details to emerge.

The Acadian Mountains

The ancient Acadian Mountains, located near today's Taconic Mountains, supplied the sediment for the Catskills during the Devonian and Mississippian periods. As the Acadians uplifted and eroded, sediment was pushed westward toward a delta.

The Ancient Delta

As the sediment was pushed into the delta, the edge of the delta moved further west. The Catskill Mountain Range is located at the delta's edge.

Erosion

During the ice ages, the tops of the Catskill Mountains were rounded and the valleys widened by glaciers. Evidence of the glaciers can be seen in the bedrock. Much of the recent sediment has been eroded, exposing the rocks from the Devonian and Mississippian eras.

Types of Rocks Found

Quartzite of many colors can be found, including: bright white, banded orange, banded tan, dark red and dark grey. Grey and blue sandstone are also found.

References

• Catskill Archive
• US Geological Service
• Catskill Mountain Keeper