Abstract
Summary: The present position of Sri Lanka and its past fit in Gondwanaland are investigated in relation to the development of the Indian Ocean. The 3 stages in the evolution of the Indian Ocean are shown to be controlled by fundamental NW, NS, and NE Precambrian lineament directions in Sri Lanka and South India. These older lineaments were rejuvenated in the Mesozoic–Tertiary to form oceanic transform faults which determined the phases of Indian Ocean floor spreading.