Three areas in peninsular India are described in which the geometric orientation of the drainage pattern has led to the location of a system of parallel crustal fractures. One area is in the Archaean basement of South India. The remainder are located on Deccan basalts. The fractures are not as a rule accompanied by fault displacements, and are regarded as planes of shearing. The shearing in the Deccan basalts cuts across the post-lava dykes, and is considered to coincide with late magmatic mineralization and the break-up of the Gondwana continent in mid-Tertiary times.