One natural and some experimental pinch-and-swell structures

Abstract

The width/thickness ratio of the swell is 3.7, which is about the same amount of elongation as the mineral grains near the swell. Then the deformation of grains decreases further away from the swell. The shape of the swell can be approximated by a mathematical function. The main mechanism of pinch-and-swell formation in the models is by sliding along shear planes.