Application of geochemistry in diagenetic features and sedimentary characteristics of Sarvak Formation, north and south flank of Mish Anticline, Gachsaran area

      Abstract   Sarvak Formation of Bangestan group is a thick sequence of carbonate rocks in Zagros basin which studied geochemically in north and south flank of Mish anticline, Gachsaran area. The thicknesses of Sarvak carbonates are 252 m in north flank of Mish anticline and 348 m in south flank of Mish anticline. Petrographic studies and microfacies analysis indicate that Sarvak Formation precipitated in a carbonate ramp so that the depth of basin is more in north flank in compare with south flank. Cementation, micritization and glauconitization are the main diagenetic features in Sarvak Formation. Cathodluminescence studies illustrated marine and meteoric cementations in south flank of Mish anticline. Variation of trace and major elements and carbon and oxygen isotopes help to separate Sarvak Formation deposits in north and south flanks of Mish anticline. Furthermore, 1000*Sr/Ca (wt) versus Fe and Mn suggest closed to semi-closed digenetic system for north flank of Mish anticline and closed digenetic system for south flank of Mish anticline. Variations of oxygen versus carbon isotope in Sarvak limestone indicate marine Phreatic and Meteoric digenesis for north and south flanks of Mish anticline, respectively.