Oligocene/Early Miocene E/W‐Shortening in the Oman Mountains Related to Oblique Arabia‐India Convergence
Andreas Scharf, Frank Mattern, Robert Bolhar, Ivan Callegari, Paul Mattern, Uwe Ring
Abstract
Abstract Field survey, literature review, geological map interpretation, GPlates reconstruction and LA‐ICP‐MS U‐Pb dating of synkinematic calcite 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‐striking contractional structures, WNW to NNW‐striking sinistral faults and ∼E/W‐striking normal faults characterize a ∼250 km × ∼50 km wrench corridor in the eastern Oman Mountains (Hajar Wrench Corridor, HWC). Numerous faults/folds indicate that deformation of the HWC is widely distributed but concentrated along WNW to NNW‐striking major faults at the SW margin of the Saih Hatat Dome, forming the Hajar Shear Zone, which 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 a minimum of 100 km E/W convergence between both plates. This convergence created the sinistral HWC 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 HWC 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‐striking Hagab Thrust in the Musandam Peninsula and the Jabal Hafit Anticline.