Application of petrography, major and trace elements, carbon and oxygen isotope geochemistry to reconstruction of diagenesis of carbonate rocks of the Sanganeh Formation (Lower Cretaceous), East Kopet-Dagh Basin, NE Iran

摘要: Postdepositional history of the Sanganeh Formation (Lower Cretaceous), in eastern Kopet-Dagh Basin northeast Iran was considered. The mainly composed shale, marl, siltstone, and interbeds limestone. study limestone led to recognizing several diagenetic processes including micritization, cementation (including isopachous rim, syntaxial overgrowth, equant mosaic spary, blocky, poikilotopic cements), neomorphism, compaction physical chemical), dolomitization, pyritization, fracturing, vein filling. Limestone samples were analyzed for major (Ca, Mg) minor (Na, Sr, Fe, Mn) elements as well oxygen carbon isotopic compositions (δ18O δ13C). Many such cementation, pyritization happen environments. In order differentiate them, geochemical data element isotopic) have been used. addition, spar, cements show different luminescence under cathodoluminescence microscope that is accordant their contents. Therefore, a guide neomorphed lime muds environments studied samples. differentiated by data. marine micrites includes mean δ18O 0.04 ‰, δ13C 1.95 Na 1491.21 ppm, Sr 5233.68 Fe 61.34 Mn 35.96. meteoric −1.02 8.85‰, 126.34 300.03 2883.88 382.88. burial mud contained −9 −6.33‰, 308.29 731.72 816.02 37.28. Paragenetic sequence carbonate rocks interpreted depicted using integration petrographic, trace elements, three phases (i) eogenesis, (ii) mesogenesis, (iii) telogenesis.