Document Type : Original Research Paper
Authors
1 Assistant Professor, Department of Geology, Faculty of Earth Sciences, Kharazmi University, Tehran, Iran
2 Professor, Department of Geology, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran
Abstract
The Sarvak Formation from the Bangestan Group, Late Albian to Cenomanian in age is an important petroleum reservoir in Iran. 5 outcrop sections in the Izeh zone, including the BangestanMountain as a type section with 831.5 m thickness, the MangashtMountain with 426 m thickness, the PayunMountain with 480 m thickness, the north flank of MishMountain with 252 m thickness and the south flank of MishMountain with 348 m thickness were studied geochemically. The major elements (Ca, Mg), trace elements (Sr, Na, Fe, Mn) and carbon and oxygen isotopes studies indicate that the geochemical characteristics of the Sarvak Formation have been changed in the Izeh zone. High amount of Sr/Mn ratio and Sr content normalized to Ca and heaviest oxygen isotope of the Sarvak Formation carbonates in the north flank of Mish Mountain and some of the Bangestan Mountain carbonate samples indicate low amount of solution and closed diagenetic system in these outcrops compare to the Sarvak Formation carbonates in the south flank of Mish and Payun Mountains. The oxygen and carbon isotopes variation illustrate marine pheriatic digenesis in the north flank of Mish and BangestanMountains and meteoric diagenesis in the south flank of Mish, Mangasht and PayunMountains. The geochemical difference, which observed in the studied sections at Izeh zone, could be related to the reactivation of deep seated structures such as the Hendijan and Bahregansar (Izeh) faults, which caused thickness, facies and diagenetic variations in these areas.
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