A Comprehensive Analysis of Basement Faults in Miocene Deposits: Fars and Bandar Abbas Perspectives

Abstract

The Zagros Fold and Thrust Belt (ZFB) in southwestern Iran emerges as a geological marvel, defined by series of compact anticlines and synclines that the NW–SE trending structures of the Zagros belt. This unique configuration designates the ZFB as the dynamic boundary of the Arabian platform, shaped by the forces of nature. Over time, sedimentation in the expansive basin led to a gradual transformation, with folds originally oriented differently nowfolds axial line inclining southwestward, revealing a progressive shift in fold axial planes. This article presents a pioneering tectono-stratigraphic examination of Miocene Formations in the Fars and Bandar Abbas Hinterland, Southern Iran. The study meticulously explores five locations—Bastak, Taghdis-e Bahar, Dasht-e Arzhan, Saedi Mountain, and Yasuj—analyzing stratigraphic sections of the Miocene Formation. The Isopach map exposes variations in Miocene Formation thicknesses across these sites. In the Arjan plain, significant facies change unfolds, transitioning from Gachsaran Formation’s evaporitic sedimentary rocks to Rzak Formation’s marine sedimentary rocks and Asmari Formation’s calcareous rocks along a northwest–southwest border. These facies change correlates intricately with subtle movements of fault zones—Kareh–Bas, Sabzpooshan, Sarvestan, and Kazerun. The tectono-stratigraphic journey unveils a profound connection between changes in sedimentary basin depth and nuanced alterations in sedimentary rocks’ facies, orchestrated by the interplay of various basement faults, some following the Arabian trend, others aligning with the majestic Zagros trend—a symphony of geological forces shaping the Miocene narrative in the Fars and Bandar Abbas Hinterland.