The Role of Basement Faults in the Miocene Formations of Fars and Bandar Abbas Hinterland, Southern Iran

Abstract

Abstract The Zagros fold and Thrust Belt (ZFB) is located in southwestern Iran. The geological structure of this region consists of a set of northwest–southeast trending compact anticlines and synclines with upright axial planes. This indicates that (ZFB) the marginal and mobile section of the Arabian platform. In the last stages of sedimentation in this vast basin, the folds are inclined to the southwest due to progressive change in the fold axial planes. For the first time, the tectono- stratigraphy of the Miocen Formations of Fars and Bandar Abbas Hinterland, Southern Iran has been studied in this article. For this purpose, the stratigraphic section of Miosen Formationin five different location namely, Bastak, Taghdis-e- Bahar, Dasht-eArzhan, Saedi mountain, and Yasuj have been collected and analyzed. To the Isopach map prepared for the region, the thicknesses of the Miocene Formations vary in all of these locations. In the Arjan plain the sedimentary facies of the evaporitic sedimentary rocks of Gachsaran Formation changes to the marine sedimentary rocks of the Rzak Formation and the calcareous rocks of Asmari Formation along a northwest – southwest border. This facies change could be related to the activity of basement fault zone such as, Kareh – Bas, Sabzpooshan, Sarvestan, and Kazerun. Tectonic- stratigraphic studies in this paper indicate that changes in sedimentary basin depth and facies changes of the sedimentary rock were affected by several basement faults that followed the Arabian trend. while others basement faults controlling the sedimentary basin in the region in Miocene are in line with the Zagros trend.