Tethyan Trench 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 Western Pacific Ocean. Subduction at the Tethyan Trench probably caused the continents Africa and India to move towards Eurasia, which resulted in the opening of the Indian Ocean. When the Arabian
Hjort Trench below sea level. To the east, the Hjort ridge follows the general curve of the trench, separating the trench from the Hjort Plateau. The Hjort trench lies in an area of transpression where the plate boundary transitions from a transform boundary to a convergent one. As such, this region provides an example of how a transform boundary with a vertical or near-vertical transform fault becomes an area of under-thrusting. Hjort Trench The Hjort Trench is a linear topographic depression south of Macquarie Island in the southwest Pacific Ocean. Geologically, the depression is considered to be the seafloor expression of an