Structural evolution of anticlines over the Hendijan Paleo-High in the northwestern Persian Gulf: Insights into the influence of inherited basement faults

Abstract

The major prolific oil fields of the Persian Gulf, located within the foredeep basin of the Zagros fold-thrust belt, have developed over north–south-trending paleo-highs formed by the reactivation of inherited basement faults. One such structure in the northwestern Persian Gulf is the Hendijan Paleo-High, over which the Hendijan, Bahregansar, and Abuzar anticlines have evolved. In this study, we investigate the structural style and progressive evolution of these anticlines through seismic interpretation, chronostratigraphic analysis, structural cross-section construction, and sequential tectonostratigraphic restoration. Our findings reveal three phases of deformation and paleo-high development, each corresponding to major tectonic events along the northeastern margin of the Arabian Plate. The first phase, recorded by growth strata within the Triassic succession flanking the Hendijan Anticline, corresponds to the onset of Neo-Tethys rifting. The second phase, involving approximately 0.5 % shortening, marks the initial formation of the Hendijan Paleo-High. Growth strata, a basal unconformity, and thickness variations within the Late Cretaceous Sarvak Formation—synchronous with the obduction of Neo-Tethys ophiolites onto the passive margins of both the Zagros and Oman—provide evidence for this phase. The third phase, associated with less than 2.3 % shortening, produced growth stratification within the Aghajari Formation during the Arabian–Central Iranian continental collision, as the deformation front advanced into the northwestern Persian Gulf during the Pliocene. We propose that reactivation of the Hendijan–Bahregansar–Nowrouz basement fault during the Late Cretaceous initiated trishear folding in the overlying strata, driving uplift of the Hendijan High and facilitating vertical hydrocarbon migration from source to reservoir. This process likely contributed to the long-term preservation of petroleum accumulations.