In the present research Kuh-e Siah Section in the Northeast of Shiraz in the Interior Fars, was investigated to study microfacies, sequence stratigraphy, facies analysis and sedimentary environment of Fahliyan Formation. Generally, 345 meters of these sediments were studied by investigating 240 thin sections. In this study, the indicator microfacies were accurately identified which include Mudstone, Wackestone, Packstone and Grainstone. Besides, skeletal and non-skeletal grains of these microfacies are Intraclast, Bioclast, Exteraclast and Peloid. According to lithostratigraphic study, underneath limit of Fahliyan Formation with the Surmeh Formation and its upper contact with Gadvan Formation were in the gradual form (SB2) and included (TST-LST-Early HST-Late HST) system tracts. In general, there were two second-degree sequences in this section., According to the analysis of the sedimentary environment, the The lowermost of the Fahliyan Formaion is comprised of the Inner shelf deposit Which changes to Open marine sediments (with homoclinal type) And eventually terminates to outer shelf deposit. Based on the received micropaleontologic data, the age determination of the Fahliyan Formation Is assigned to Neocomian. Manuscript profile

In the easternmost part of the Izeh Zone of the Zagros Mountains, the Kazhdumi Formation of upper Aptian-middle Albian interval is superbly exposed in three-main exposures as argillaceous carbonate facies. The main bioclastic components of the Kazhdumi Formation are Orbitolinid and other larger benthic foraminifers, planktonic foraminifera and calcareous algae. The depositional system in the study area during the upper Aptian-middle Albian corresponds to a shaly carbonate ramp. Two depositional sequences are determined, as prograding system from west to east. Comparison of the proposed depositional sequences with those reported in the Arabian Plate and adjacent areas suggests a correlation with the global sea-level curve. The Lower Cretaceous, Aptian carbonates of Kazhdumi Formation contain nine microfacies, which were deposited on a ramp system deepened in both directions (west and east). Stratigraphic sequence led to recognize two third-order sequences. On the other hand, rudstone and boundstone lithofacies of the studied formation have higher reservoir potential and were deposited during Apt 3 and Apt 5 sequences of the Arabian Plate. The Kazhdumi Formation in the study area was deposited in an intrashelf basin that should be classified as an independent basin in the future paleogeographic maps of the southwest Iran. We interpret the Kazerun Fault, as a crustal warping of basement faults of the Arabian Plate boundary, which were responsible for the creation of the intrashelf basin in the study area. Manuscript profile

The investigation of lithostratigraphy, biostratigraphy and the microfacies analysis of the Gadvan Formation as an oil reservoir of Lower Cretaceous in the Zagros Basin is crucial. In this study Naser Abad section (Coastal Fars region, SW of Iran), consists of 170 meters thin to medium-bedded limestone with interbeds shale and marly limestone. According to stratigraphic distribution of identified foraminifers, two biozones are established which are: Paleorbitolina lenticularis zone and Hedbergella infracretacea Zone. Based on the investigated faunal assemblage, the age of Gadvan Formation is assigned to late Barremian-early Aptian. Microfacies studies led to the identification of five microfacies types which include: Algal-intraclast- bioclast wackestone, Intraclast- bioclast wackestone, Planktonic- bioclast wackestone, Radiolarian packstone and Orbitolina- bioclast wackestone. These microfacies show that the Gadvan Formation was deposited in both shallow water ramp and hemipelagic paleoenvironments. According to microfacies, carbonate platform of Gadvan Formation in the studied area corresponds to a moclinal platform which was affected by basement of Kazerun Fault zone. Manuscript profile

Tarbur Fonnations in southeast of kherameh with 700 m thickness are dominantly formed from carbonate rocks. The lower boundary with gurpi formation is conformable and the upper boundary with Sachun Formation is marked by an erosional surface. According to the lithological characteristics of the Tarbur Formation six lithological units in Kherameh area were recognaized.The study of pertrography indicates that carbonate sediments of the Tarbur Formation can be divided into 8 groups of carbonte microfacies, including: 01,02 (Open marine), B (Barrier) and Ll to L5 (Lagoon). Vertical changes in microfacies and diagram of the sea level show that sedimentation of the Tarbur Formation took place in a shallow environment. Tarbur Formation in the study area is formed in a carbonate platform (epicontinental sea), in a homoclinal ramp. Manuscript profile

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. Manuscript profile