Diamantina Fracture Zone Ridge Plateau. All these features are mirrored by corresponding topography on the other side of the Southeast Indian Ridge. Broken Ridge Plateau was formed at the ridge together with the Kerguelen Plateau. Diamantina Fracture Zone was first detected by and RV Argo in 1960. It is named after , which did further exploration in 1961. The Diamantina Deep is the zone's deepest location, located about 1 125 km West-South-West of Perth, Western Australia, at . This is not the deepest point in the Indian Ocean: the CIA's Physical Map of the World lists the Java Trench as such. On the
Tethyan Trench and Indian plates collided with Eurasia, the Tethys Ocean and the trench closed. Remnants of the Tethyan Trench can still be found today in Southeastern Europe and southwest of Southeast Asia. Tethyan Trench The Tethyan Trench was an ancient oceanic trench that existed in the northern part of the Tethys Ocean during the middle Mesozoic to early Cenozoic eras. The Tethyan Trench formed when the Cimmerian Plate was subducting under eastern Laurasia, around 200 million years ago, in the Early Jurassic. The Tethyan Trench extended at its greatest during Late Cretaceous to Paleocene, from what is now Greece to the