"Shearing stresses acting on an incompetent layer confined between competent beds during its deformation in the development of folds, differ from those commonly accepted as the cause of a number of minor structures associated with the deformation. It is suggested that the effect of bedding drag is negligible, and that the structures described as slaty cleavage, fracture cleavage, and drag folds can be explained by the laminar flow of the incompetent material whilst accommodating itself to the interspaces determined by the more competent layers."

You do not currently have access to this article.