The Champlain Thrust Fault, on Lake Champlain in Vermont. Photo by Mike Luoma.

Visiting The Champlain Thrust Fault

Science Can Be Beautiful

Some 440 Million years ago in what would later become Vermont, the land form including future New Hampshire and Maine came slamming in, pushing up the Green Mountains in what’s known as the Taconic Orogeny.

On the shore in front of the Champlain Thrust Fault. Photo by Mike Luoma.

When that happened, beautiful tan to orange bedrock called Lower Cambrian Dunham Dolostone, about 500 million years old, was pushed over a younger, darker rock, the gray Middle Ordovician Iberville Shale, around 460 million years old, creating this fault. Because older rock above younger rock reverses the usual order of things, it’s called a reverse fault.

This reverse fault is the Champlain Thrust Fault, which runs from Quebec, Canada down to the Catskills Plateau, almost 200 miles in length.

Dunham Dolostone over Iberville Shale — The Champlain Thrust Fault. Photo by Mike Luoma.

It’s known as a Thrust Fault due to its low angle to the Earth’s surface.