Facies Analysis, Depositional Environment of the Lower Permian Deposits of Chili Formation in Kalmard Block, Eastern Central Iran (Darin Section)

摘要

Early Permian deposits in north of Kalmard region recognize with formal group of Khan; they have various features in the different place. This group includes four different formations from lower to the upper part: Chili, Sartakht and Hermez. These formations consist of carbonate rocks. Chili Formation has 104 m, thickness in Darin section and consists of limestone with intermediates of shale and marland sandstone. Lower boundary of this formation is disconformable with Gachal formation. The upper boundary is separated by unconformity from the upper part Sartakht formation according to the lithological characters and microscopic studies, cause identifications of beach, intertidal, open and semi-restricted lagoon, shoals and bar and open marine sub-environ- ments for the Chili Formation. Vertical changes of microfacies and depth changes curve show much more thickness of shoals and bar microfacies, and little thickness of open and semi-re- stricted lagoon and open marine microfacies. Deposits of Chili Formation in Darin section deposited in the gentle gradient Homoclinal ramp in the south of Paleotethys Ocean. Two depositional sequences have been identified in this formation, based on recognized Fusulinid, show age of Sakmarian, which has adaptation with Lower Absaroka III.