Geology of Indian Ocean

The Indian Ocean, as the youngest of the main oceans, includes active spreading ridges that are part of the global system of mid-ocean ridges. These spreading ridges meet in the Indian Ocean at the Rodrigues Triple Point, where the Central Indian Ridge, including the Carlsberg Ridge, separates the African Plate from the Indian Plate, the Southwest Indian Ridge separates the African Plate from the Antarctic Plate, and the Southeast Indian Ridge separates the Australian Plate from the Antarctic Plate.

The Owen Fracture Zone reaches the Central Indian Ridge and intercepts it. The Indian Ocean contains two trenches: the Java Trench between Java and Sunda and the Makran Trench south of Iran and Pakistan. The Indian Ocean is traversed by a succession of ridges and seamount chains formed by hotspots. The Réunion hotspot connects Réunion and the Mascarene Plateau to the Chagos-Laccadive Ridge and the Deccan Traps in northwestern India; the Kerguelen hotspot connects the Kerguelen Islands and the Kerguelen Plateau to the Ninety East Ridge and the Rajmahal Traps in north-eastern India; and the Marion hotspot connects the Prince Edward Islands to the Eighty-Five East Ridge. The previously described, still ongoing spreading ridges have disrupted these hotspot pathways.