The objective of this study was to describe the little-known structure and stratigraphy of the Strait of Hormuz in terms of the better known stratigraphy and tectonic history of the Oman region. Four structural provinces surround the Strait of Hormuz: (1) the Zagros fold belt to the northwest (2) the Arabian Platform to the southwest, (3) the Makran Basin to the east and (4) the Oman Mountains to the south. The development of these structural provinces, over 260 Ha of geologic time, influenced the stratigraphy and structure of the Strait. This was the result of rifting and sea-floor spreading (opening of Neo-Tethys) in the late Paleozoic and early Mesozoic and a variety of tectonic events associated with the closure of Neo-Tethys and the northward motion of the Arabian Plate, from mid Cretaceous to Recent.

The stratigraphic section encountered in the Strait ranges in age from Infracambrian to Recent and is composed of four depositional sequences bounded by prominent regional unconformities. These include; Permian-Triassic rift sequence deposited during the opening of Neo-Tethys, a Jurassic-mid Cretaceous carbonate shelf sequence, a late Cretaceous orogenic sequence and Tertiary-Recent orogenic and post-orogenic deposits.

The most dramatic regional tectonic event was the closing of the Tethyan seaway during the late Cretaceous, illustrated by thrusting of the Hawasina nappes and obduction of the Semail ophiolites along the eastern Oman margin, south of the Dibba Zone. Structural development associated with this event is not easily recognized in the Strait. This is because of the overpowering structural effects of the younger Miocene compressional episode, the most important tectonic event recorded in the Strait.

Miocene structuring resulted in the formation of anticlinal and horst features associated with thrust faulting, resulting in a SSW-NNE structural grain paralleling the Oman Peninsula. These structural highs were subsequently eroded, producing a prominent angular unconformity which is easily identified on seismic sections. Some of the structuring was locally enhanced by diapirism of the underlying Hormuz Salt. Above this unconformity is a relatively flat-lying post-orogenic sequence of Miocene limestones, shales and sandstones which would constitute a potential seal for any hydrocarbon accumulations reservoired in the underlying structures.

Potential reservoir facies include fractured Middle Cretaceous to Lower Tertiary limestones present under the Miocene unconformity and thick, eastward-thickening, turbidite deposits of the same age. Numerous wells drilled in the Southern Arabian Gulf Basin, west of the Strait have encountered both oil and gas. The occurrence of oil and gas wells, along with numerous shows and undrilled structures indicate that this area should be given careful consideration for future exploration.

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