Microfacies, depositional environment and sequence stratigraphy of the Dariyan Formation in the north of Shiraz

The Dariyan Formation (Aptian- Albian) is one of the important hydrocarbon reservoirs in the SW of Iran. In this investigation, microfacies, depositional environment and sequence stratigraphy of the Dariyan Formation have been studied in the Sivand and Dashtak anticlines in the north of Shiraz. The thickness of the Dariyan Formation in the Sivand section is 330 meters and in the Dashtak section is 263 meters. It mainly consists of limestone and shale interbeds. The lower contact of the Dariyan Formation with the Gadvan Formation is gradational and the upper contact with the Kazhdumi Formation is disconformity. Field and microscopic studies of the Dariyan Formation have led to recognition of 3 groups and 11 microfacies related to open marine, barrier and lagoon environments. These facies groups were formed in a rimmed shelf carbonate platform. Vertical facies variations indicate the presence of one 3rd sequence. The lower part of TST is in the Gadvan Formation and the upper boundary of HST with Kazhdumi Formation is SB1.