Tectonic types of deepwater basins in the Indian Ocean

Abstract

Among 16 deepwater basins located in the central Indian Ocean and along its western, eastern, and southern margins, the central, perioceanic, and perispreading tectonic types are recognized. The Central, Cocos, Wharton, and Crozet basins belong to the first type. The second type comprises the Somalia, Mascarene, Madagascar, Mozambique, and Agulhas basins localized along the western margin of the ocean; the Argo, Gascoyne, Cuvier, and Perth basins that are situated along its eastern periphery; and the African-Antarctic Basin in the southern periphery. The South Australian and Australian-Antarctic basins pertain to the third type. Spatially and tectonically, the pericontinental basins are conjugated with continental blocks in the ocean (rises, plateaus, microcontinents). Together, they make up specific tectonic systems that extend parallel to the continents. The formation of such systems is controlled by horizontal movement of continental blocks and tectonic subsidence of the oceanic bottom.