Evidences on the presence of Jurassic continental rift system in the Ravar area, Southern Tabas Block

The Ravar zone, a wedge-shaped terrane, situated at the southern Tabas block, is confined between two main boundary faults, the Nayband fault in the east and the Kuhbanan fault in the west.  The Mesozoic strata, especially the Jurassic layers, have a variety of facies, distribution, and exposure. Structural restoration and stratigraphical correlation between the Jurassic layers on the basis of the field and lab studies in the Ravar zone, brought new result.  The stratigraphy, structure, and magmatism of the middle Jurassic to late Cretaceous successions are similar to the deposits which have been evolved in the continental rift zone is being transited to a passive margin.  The sedimentary successions are classified into two groups; the clastic deposits of the Hojedk and Baghamshah Formations, and carbonate-evaporate of the Pectinid layers, and alkali basalts of the Ravar Series which are considered as the syn-rift series. The second group composed of lower Cretaceous red marl and evaporate as well as upper Cretaceous marine limestone well-thought-out as the post-rift series. These two series are separated by pronounce angular unconformity and basaltic volcanic rocks in the Ravar zone. Deepening towards the west, indicates that the main ocean, in the Cretaceous time, must be at the west side, somewhere at the west of the Tabas block. The Nain and Dehshir-Baft ophiolites could be the best candidates for the remnants of this ocean.