Basement morphology of the fold-and-thrust belt and foreland basin of the United Arab Emirates: Evidence for thick-skinned tectonics in the northern Oman-UAE Mountains

We determined the basement depths in the fold-and-thrust belt (FTB) and the associated Aruma and Pabdeh foreland basins of the United Arab Emirates. Additionally, we investigated the relationship between shallow sedimentary structures and deep basement features. The Late Cretaceous Aruma basin is associated with Semail ophiolite thrusting and loading, while the late Oligocene to Miocene Pabdeh basin is associated with the culmination of Musandam and early Zagros collision. In the northern portions of the study area, seismic reflection profiles and derivative maps of gravity and magnetic data show NNW-SSE striking thrusts, backthrusts, and folds. The southern region around Jabal Hafit is dominated by the Tarabat backthrust, which cuts across the Upper Cretaceous and Cenozoic successions. Moreover, the Mesozoic platform carbonates are dissected by thrust faults. These thrusts may have originated from Jurassic extensional faults that were reactivated during the Late Cretaceous ophiolite obduction, as well as the late Oligocene to the early Miocene culmination of Musandam resulting from the collision of the Arabian Plate and Central Iran along the Zagros Suture. Results of the 3D gravity inversion indicate that the basement depths range from 11.5 km along uplifted areas of the FTB to 18.8 km within the deeper parts of the foreland basin. Significant northward increases in both basement depth and the thickness of the late Oligocene-early Miocene successions indicate a northward increase in the severity of thrusting and crustal loading along the Khusub thrust. The basement uplifts are found to be correlated with shallower anticlinal features, indicating a direct relationship between basement uplifts and shallow sedimentary structures. Therefore, we suggest that the basement structures were reactivated during the Late Cretaceous ophiolite obduction and the late Oligocene-early Miocene Zagros collision.

Automated summary

In this study, the basement depths in the United Arab Emirates' fold-and-thrust belt (FTB) and its associated foreland basins were determined and the relationship between shallow sedimentary structures and deep basement features was investigated. The results showed that thrusts, backthrusts, and folds were observed in the northern portions of the study area, while the Tarabat backthrust dominated the southern region. The 3D gravity inversion results suggested an increase in basement depth and the thickness of late Oligocene-early Miocene successions towards the north, indicating a northward increase in the severity of thrusting and crustal loading along the Khusub thrust. The correlation between basement uplifts and shallower anticlinal features suggested that the basement structures were reactivated during the Late Cretaceous ophiolite obduction and the late Oligocene-early Miocene Zagros collision.