Andreas Scharf

and 5 more

Field survey, satellite image interpretation, geological map interpretation, literature review, GPlates reconstruction and LA-ICP-MS U-Pb dating of synkinematic calcites demonstrate that ~E/W-shortening in eastern Oman was significant and related to oblique convergence of Arabia and India from 32.5 to 20 Ma. Approximately N/S-oriented compressive structures, WNW to NNW-striking sinistral faults and ~E/W-oriented normal faults characterize a major shear zone in the eastern Oman Mountains (Hajar Shear Zone, HSZ) and its wrench-fault assemblage within an area spanning ~250 km x ~50 km. More than 10,000 mostly NW-striking lineaments as deduced from satellite image interpretation and numerous faults/folds indicate that strain of the HSZ is widely distributed but concentrated along WNW to NNW-striking major faults/fault zones at the SW margin of the Saih Hatat Dome. These faults/fault zones represent reactivated basement faults. GPlates reconstructions reveal that N-drifting India rotated 8° counter-clockwise with respect to fixed Arabia from 32.5 to 20 Ma, leading to ~100-135 km E/W-convergence between both plates (minimum value). This convergence created the sinistral HSZ with a displacement of a few to several tens of kilometers. Independently from the GPlates time constraints, two U-Pb ages of synkinematic calcites, crystallized along faults during HSZ movement, yield compatible ages of 30.08 ±0.47 and 22.31 ±2.15 Ma (2 standard error). E/W-shortening also affected the northern Oman Mountains, creating the ~N/S-oriented Hagab Thrust in the Musandam Peninsula and the Jabal Hafit Anticline.

Susanne Schneider

and 4 more