The tectonic succession of the Oman Mountains, including the Semail ophiolite complex, resembles that underlying the Zagros thrust zone of Iran. Palinspastic reconstruction of the Oman sequence indicates a Triassic continental-margin–ocean-basin regime that underwent subduction on its northeastern margin during much of Cretaceous time. The sequence resulted from tectonic incorporation of ocean-basin and margin lithologies into a lower trench slope accretionary prism. Emplacement of large ophiolite (oceanic lithosphere) slices within the accretionary prism may have resulted from attempted subduction of a topographic irregularity such as a recently inactive oceanic rise. Collision, or partial collision, of continental margins resulted in tectonic emplacement of the accretionary prism onto the previously stable platform sequence. This model includes implications concerning the regional tectonic development of the Zagros thrust zone and central Iran and may account for differing characteristics of regions to the northeast and southwest of the Zagros thrust.