cleft

A cleft is a sizable crack, fissure, crevice, or rift in a rock surface. It is smaller than a cave or cavern, and, unlike those landforms, it gives the appearance of having been created by an abrupt fracturing or splitting action rather than by a gradual process of erosion or subsidence. Probably through a confusion with cliff, it is sometimes spelled clift. The writer James Kilgo, in An Inheritance of Horses, describes meeting a man named Roy in the mountains of north Georgia. Roy tells a story of a hound that fell into a rock clift. Kilgo asks him exactly what a rock clift is. “Why it’s kindly like a hole.” “A hole in the ground?” “No. It’s where you have a clift in the rock.” He paused, then continued, “Hell, it’s just a rock clift, is what it is."

Franklin Burroughs