نوع مقاله : مقاله پژوهشی
نویسندگان
1 _گروه زمین شناسی ، واحد تهران شمال، دانشگاه آزاد اسلامی، تهران، ایران
2 _گروه زمین شناسی ، واحد مشهد، دانشگاه آزاد اسلامی، مشهد، ایران
3 دانشیار، گروه زمین‌شناسی، دانشکده علوم پایه، دانشگاه آزاد اسلامی، واحد تهران شمال
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Petrographic studies led to the identification of 18 microfacies that were deposited in four facies belts open marin, lagoon, Barrier and tidal flat. The frequency of tidal facies along with barrier facies and the absence of large reef barrier and turbidite sediments indicate the deposition of this formation in a ramp system with a carbonate slope. Diagenetic processes in this formation include: cementation, micritization, dissolution, compaction, dolomitization, fracture, stylolitification and silicification. For geochemical studies, 41 samples were analyzed by ICP-OES method in Iran-Karaj Mineral Processing Research Center (Emidro Company) for elemental analysis and by ICP-MS method in Science Laboratory Center of Ottawa University of Canada for carbon isotope and oxygen. The abundance of skeletal and non-skeletal components of calcite along with calcite cement, abundance and presence of dolomite with high content of stransiom refers to the initial mineralization of calcite in the carbonates of Tirgan Formation in time. Also, the values of major (Mg, Ca) and minor elements (Sr, Na, Mn, Fe) and the isotopic range of oxygen 18 and carbon 13 of the limestones of Tirgan Formation, also indicate the composition of primary calcite mineralogy in these areas. This value also shows the impact of the burial diagenesis environment on these deposits in a semi-closed diagenesis system with a low water-to-rock ratio.
کلیدواژه‌ها [English]
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