Cross fold deformation by simple shear

Abstract

The effects of simple shear on various types of preexisting structure are studied by means of laminar models. Interaction of relatively uncomplicated forms and shear deformations produce complicated effects where axes of earlier and later structures are at a low angle to one another. Similarities of fold and lode patterns of the Broken Hill district, New South Wales, with effects produced in the model study suggest that modification of earlier structures by superposed simple shear has been an important mechanism in the district. This interpretation suggests criteria for dating ore-forming processes as pre- or post-structure.