Structure of the northern Oman Mountains from the Semail Ophiolite to the Foreland Basin
Published:January 01, 2014
D. J. W. Cooper, M. Y. Ali, M. P. Searle, 2014. "Structure of the northern Oman Mountains from the Semail Ophiolite to the Foreland Basin", Tectonic Evolution of the Oman Mountains, H. R. Rollinson, M. P. Searle, I. A. Abbasi, A. I. Al-Lazki, M. H. Al Kindi
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The northern Oman Mountains record the Late Cretaceous emplacement of the Semail Ophiolite and associated subduction trench and deeper-water sediments into a foredeep on the downwarped Arabian continental margin. In-sequence piggy-back thrusting was modified by later thrust sheets of Permian–Mesozoic continental slope sediments that breached the overlying allochthonous stack. Sections through these culminations show asymmetries linked to deep-seated faults perpendicular to the margin edge which created offsets (promontories) that influenced detachment. Seismic profiles across the foredeep indicate an unconformity at the top of the Mesozoic carbonate platform, the product of early flexural uplift, onlapped by sediments. A second onlap phase is linked with rapid subsidence during final emplacement of the allochthon. Passive margin conditions resumed during Maastrichtian time, conformable along the axis of the foredeep. A Paleocene–Eocene (Pabdeh) foredeep was initiated in the northern mountains, recorded on seismic profiles with another onlapping sequence. Subsidence and infill persisted into the Oligocene when compression, linked with the Zagros collision, resulted in uplift and en echelon folding, probably due to the reactivation of deep-seated faults. Post-Miocene erosion of one culmination exposed the cap of a gypsum/anhydrite intrusion. The origin remains uncertain, but derivation from the Neoproterozoic to Cambrian Ara Group salt is preferred.
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Tectonic Evolution of the Oman Mountains
The Oman Mountains contain one of the world's best- exposed and best-understood fold–thrust belts and the largest, best-exposed and most intensively studied ophiolite complex on Earth. This volume presents new international research from authors currently active in the field focusing on the geology of the Oman Mountains, the foreland region, the carbonate platforms of Northern and Central Oman and the underlying basement complex. In addition there is a particular focus on geoconservation in the region. The volume is divided into three main sections that discuss the tectonics of the Arabian plate using insights from geophysics, petrology, structural geology, geochronology and palaeontology; the petrology and geochemistry of the Oman Ophiolite and the sedimentary and hydrocarbon systems of Oman, drawing on the geophysics, structure and sedimentology of these systems. The volume is enhanced by numerous colour images provided courtesy of Petroleum Development Oman.