Microfacies and Original Mineralogy in Ilam Formation based on geochemistry and isotopical studies in type section, payun anticline and DA#a

ilam formation from bangestan group with santonian to campanian age is consisting of carbonate unit s . This formation is disconformably overlain by surgah and sarvak formations and underlain by gurpi formation in type section payun anticline and DA#a , zagros basin , southwest of iran .detailed petrographic investigations have led to the recognition of 13 microfacies and six microfacies belt associations: tidal flat , lagoon, shoal, slope, open marine and basin in a ramp platform of ilam carbonates. major (Ca,Mg) and minor elements (Sr,Na,Fe,Mn) and carbon and exygen isotope quantities used to determine carbonate mineralogy in ilam formation. bivariate plots of major and minor evements and oxygen and carbon isotope values indicate that mixed aragonite and calcite were the original carbonate mineralogy in studied sections. paleotemperature calculation based on heaviest oxygen isotope quantity of the least altered sample, indicate that sea water temperature during precipitations of ilam formaiton was 28 C.

کلیدواژه ها:

bagestan group ، ilam formation ، carbon and oxgen isotopes ، aragonite and calcite