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
Oceanic trench was not recognized until well into the 20th century. The term “trench” does not appear in Murray and Hjort’s (1912) classic oceanography book. Instead they applied the term “deep“ for the deepest parts of the ocean, such as Challenger Deep. Experiences from World War I battlefields emblazoned the concept of a trench as an elongate depression defining an important boundary, perhaps leading to the term “trench” being used to describe natural features in the early 1920s. The term was first used in a geologic context by Scofield two years after the war ended to describe a structurally controlled depression in