Canyon and Cliff Talus (November 11)

One of the ways to determine whether a canyon or cliff has been recently formed–or is very old–is to look at the pile of rubble at the base of the cliff or canyon. This rubble is the result of wind, rain, and temperature changes wearing away at the cliff face – resulting in material falling away from the vertical face and accumulating as a pile at the bottom of the cliff. This rubble at the base of a steep slope is called “talus.” **The older the canyon or cliff, the more talus there should be at the bottom.** Eventually, the vertical wall should completely disappear and be replaced by a sloped pile of accumulated talus.

The fact is many, if not most, cliffs and canyons in the Western United States, and many other places around the world, still have vertically-walled valleys and have relatively small piles of talus at the base of cliffs. This is strong evidence for young geological features. If these vertical canyons and cliff walls were millions of years old, they would have eroded away long ago. Vertical canyons and cliff walls with little talus testify to a young Earth. So the next time you see a canyon or cliff, examine how much The Mystery of Missing Talusexists at its base.