Taughannock Falls Gorge Trail By Cayuga Lake Stock Photo

As you look around the gorge, you cannot miss the layers of rock. 380 million years ago, this area was all at the bottom of an ancient sea. The floor of the gorge is a light gray limestone, the evolution of lime mud that was made from algae and other marine organism shells. You can see fossilized remains in the floor of the stream and some of the large stone blocks at the base of the falls. The crumbling walls of the gorge are shale, composed of clay and silt that fell on top of the lime mud and hardened into rock. At the very top of the cliff walls are sturdier layers of sandstone and siltstone.nThe ancient sea that covered much of New York during the Devonian period before the dinosaurs was slowly filled with eroded sand, silt and clay from the Acadian Mountains to the east. These materials turned into rock from both natural cementing and pressure from material that fell on top of these sediments.nRemember geology class? Chemical and physical weathering? You can see it in action at Taughannock. The limestone in the stream bed is pitted in spots, due to chemical weathering from slightly-acidic rainwater. Freezing and thawing of the gorge walls splits the shale into fragments that eventually fall. That’s physical weathering, and it makes climbing the fragile walls extremely dangerous.n