Sedimentary environment and diagenesis of the Nayband Formation in Bolboluieh section, East of Kerman

The Nayband Formation (Norian_Rhaetian) in Bolboluieh section includes 105m of limestone, quartzarenite, lime shale and shale. Orthochemical, allochemical carbonate components (skeletal grains and non_skeletal grains) and also allochemical and orthochemical non_carbonate components form deposits of the Naiband Formation. Orthochemical components consist of cements, micrite, microspar and pseudospar. Skeletal grains include foraminifer, sponge, gastropod, brachiopod, echinoderm and bivalve. Non_skeletal grains include ooid, peloid and cortoid. Allochemical non_carbonate components include clastic quartz. Field and petrographic studies led to identification of carbonate microfacies of sandy peloidal oolitic packstone in sand shoals, bioclastic wackestone in outer ramp/sandy bioclastic wackestone with diverse fossils in middle ramp, bioclastic grainstone with echinoderm in sand shoals and sandy mudstone in lagoon and clastic petrofacies included quartzarenite in offshore transition environment, shale in offshore transition environment and lime shale in offshore environment . Based on observed facies pattern and field studies, we can suggest a homoclinal carbonate ramp as sedimentary environment of the Nayband Formatin in the studied area. Studied deposits have been affected by marine diagenesis (micritization and calcitic cementation of sandstones), meteoric diagenesis (neomorphism, pendent, meniscus and syntaxial cements) and burial diagenesis (fracture in grains and stylolitization).