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
Rocky Mountain Trench Castlegar, BC after a meander through the United States as the Kootenai River (US spelling). For convenience the Rocky Mountain Trench may be divided into two sections, the Northern Rocky Mountain Trench and Southern Rocky Mountain Trench. The dividing point reflects the separation of north and easterly flows to the Arctic Ocean versus south and westerly flows to the Pacific Ocean. A break in the valley system at ~54°N near Prince George, British Columbia may be used for this purpose. The northern portion of the Trench is dominated by strike-slip faulting, while the southern part of the Trench was created