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
Chapada Diamantina 25 km wide and exposes the sedimentary rocks of the Paraguaçu group. At the contact there are two different rock groups exposed one being the Chapada Diamantina and the Paraguaçu, with the Chapada Diamantina overlaying the Paraguaçu group. The two rock groups not only in elasticity but in composition as well. The Chapada Diamantina is composed primarily of sandstone, pelites and diamond bearing conglomerates. The Paraguaçu is composed of fine-grained sandstones, siltstones and argillites. The rocks of the Paraguaçu are softer and therefore more susceptible to weathering and folding. It is the folds in the Paraguaçu that allows for the