Facies analysis and sedimentary environments of Sachun Formation in Kuh-e-Siah section, southeast of Sarvestan (Fars Province)

Abstract

The Sachun Formation in the Sarvestan section (472 meters) is sandwiched between the Tarbur and Jahrom Formations. Its upper contact with the overlying Jahrom Formation is conformable, but its lower boundary with the underlying Tarbur Formation is unconformable. The formation consists mainly of evaporite, shale/marl and carbonates that are arranged into a number of shallowing upward cycles. Facies of the Sachun Formation were deposited in 4 facies belts (supratidal, intertidal, lagoon and barrier facies belts) related to a ramp platform. The Sachun Formation was deposited during a sea level low stand that occurred after Laramid Orogeny. Therefore, in contrast to previous beliefs, its deposition started in Early Paleocene times.