Collapse Structures

Abstract

RECENT reconnaissance surveys in south-west Persia have brought to our notice many examples of enigmatical structures preserved in massive limestones beautifully exposed in the naked mountains of that region. Application of many hypotheses involving faulting and thrusting proved impossible to satisfy the facts we had observed. We were at length forced to explain some of the structures we encountered as being produced by collapse of great sheets of limestone after removal of their original supporting cover accompanied by unsticking from their basement. Gravity alone provided the motive force. Simple folds, erosion, a shaly substratum, and gravity have induced massive beds of limestone to behave in an entirely unexpected manner. Examples are described below with sketches.