Gorge View Of Eroded Rock Walls And Creek Below Royalty-Free Stock Image

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. 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