Extract

The Oman Mountains which occupy the southeastern corner of the Arabian Peninsula form an arcuate chain, approximately 700 km long and up to 120 km wide, stretching from the Arabian Gulf and Straits of Hormuz in the northwest to the Arabian Sea in the southeast. The Range forms the southeastern margin of the Arabian continental plate, which is bounded by the Red Sea spreading centre in the west, the dominantly transform fault-bounded Arabian Sea margin along the southeast coast and the major Tethyan suture zones along the northern and eastern margins, exposed in Iran, Pakistan and Turkey. The Gulf of Oman is floored by Cretaceous oceanic crust which is currently subducting northwards beneath the Makran active continental margin (White & Ross 1979). Thus the Oman Mountains define a continent-ocean collision boundary of dominantly Late Cretaceous age, but affected by further compression and uplift during the Tertiary.

The Oman Mountains are well known for the world’s largest intact and best exposed obducted ophiolite complex, the Semail ophiolite. Underlying the ophiolite is a complicated assemblage of thrust sheets of proximal to distal deep-sea sediments, volcanic and melange units, termed the Hawasina Complex and the Haybi Complex. These thrust units, are in turn structurally underlain by carbonate slope deposits (Sumeini Group), which have been thrust onto the Arabian platform. The shelf carbonate successions are part of the giant Middle Eastern hydrocarbon province and the Oman foreland has been subjected to extensive subsurface seismic exploration and drilling operations. The Oman Mountains are also exceptionally well