Diamantina Fracture Zone Diamantina Fracture Zone The Diamantina Fracture Zone is an area of the south-eastern Indian Ocean seafloor. It has a range of ridges and trenches. It lies to the south of the mideastern Indian Ocean features of the Wharton Basin and Perth Basin, and to the south west of the Naturaliste Plateau. Being parallel to the Southeast Indian Ridge, Diamantina Fracture Zone is not a real fracture zone in the sense of plate tectonics, but rather an escarpment, separating two oceanic plateaus. In fact its extension to the west is called Diamantina Escarpment. This is the southern border of the Broken
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