Investigation of tectonic history of Sefid-Zakhor anticline, Fars province

Document Type : Original Article

Authors

1 Department of Earth Sciences, Department of Science, Faculty of Science, Technology and Modern Agriculture, Islamic Azad University, Shiraz Branch Shiraz, Iran.

2 Assistant Professor, Department of Earth Sciences, Department of Science, Faculty of Science, Technology and Modern Agriculture, Islamic Azad University, Shiraz Branch Shiraz, Iran.

3 Iran Oil Industry Research Institute, Tehran, Iran.

Abstract

Abstract
The Sefid-Zakhur anticline is located in an area of Fars province where the gas potential on the Dehram horizon is high. The restored sections have been studied in three western, eastern and central parts of this anticline, deformation in this area is caused by a combination of compressive and shear deformation and tilting of layers in the end sections in the non-deformation stage, it indicates the existence of shear plates (separation horizons) between the stratigraphic units. Based on the order of formation of faults on sections, it can be concluded that first progressive thrusts and then as the deformation progresses, back thrusts are formed. The deformation in this region is related to the beginning of the Zagros deformation in Miocene time and is not older than that. According to the growth strata observed in the carbonate member of Gachsaran Formation in Sefid-Zakhur anticline, compression and folding in this area occurred during the Early Miocene. The southwestern part began to form earlier and formed as detachment fold with box geometry above the lower detachment horizon. In the higher deformations, the deformation occurs to the northeast, and the anticline forms detachment fold with a chevron geometry. The geometry of fold in the eastern part is a box fold. The degree of deformation in the eastern part is less than the central and west parts. Generally, Sefid-Zakhor field and its surrounding fields are formed based on the action and reaction of the compressive force of the region and the separation horizon.

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