Early cretaceous platform-margin configuration and evolution in the central Oman mountains, Arabian peninsula

Journal Article · Mon Feb 01 00:00:00 EST 1993 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:6106701

Pratt, B R ^[1]; Smewing, J D ^[2]

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1. Univ. of Saskatchewan, Saskatoon (Canada)
2. Univ. Innovation Centre, Swansea (United Kingdom)

The Hajar Supergroup (Middle Permian-Lower Cretaceous) of northeastern Oman records rifting and development of a passive margin along the edge of the Arabian platform facing Neo-Tethys. The Jurassic and Lower Cretaceous part, comprising the Sahtan, Kahmah, and Wasia groups, was deposited during the maximum extent of the broad epicontinental sea landward of this margin. These limestone units reach a total of 1500 m in thickness and correlate with the hydrocarbon reservoirs of the Arabian Peninsula. The trace of the Jurassic and Cretaceous margin in northeastern Oman followed a zigzag series of rift segments, resulting in promontories and reentrants that changed in position through time in response to the configuration and differential motion of underlying rift blocks. Synsedimentary normal faulting occurred locally in the Middle Jurassic, whereas in the Late Jurassic, the margin was eroded from variable uplift of up to 300 m before subsiding to below storm wave base. This uplift may have been caused by compression from oceanic crust that obducted along the southeastern side of the platform. The Lower Cretaceous succession in the central Oman Mountains and adjacent subsurface began with regional drowning around the Jurassic-Cretaceous boundary. The succession in the east (Saih Hatat) records a single regressive sequence, ending in the progradation of the shallow-water carbonate platform by the Cenomanian. However, the succession in the west (Jebel Akhdar and interior) is dominated by shallow-water carbonate facies, but punctuated by a second regional drowning in the late Aptian. A third, Late Cretaceous drowning terminated deposition of the Wasia Group in the Turonian and was caused by convergence of oceanic crust and foreland basic formation. The record of tectonic behavior of carbonate platforms has important implications for the development of hydrocarbon source rocks and porosity. 68 refs., 11 figs., 1 tab.

• OSTI ID: 6106701
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 77:2; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
58 GEOSCIENCES
HYDROCARBONS
DEPOSITION
LIMESTONE
ORIGIN
OMAN
GEOLOGIC HISTORY
BASEMENT ROCK
CONTINENTAL MARGIN
CRETACEOUS PERIOD
GEOLOGIC FAULTS
GEOLOGIC STRUCTURES
MOUNTAINS
OCEANIC CRUST
PLATE TECTONICS
RESERVOIR ROCK
RIFT ZONES
ARAB COUNTRIES
ASIA
CARBONATE ROCKS
DEVELOPING COUNTRIES
EARTH CRUST
GEOLOGIC AGES
GEOLOGIC FRACTURES
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MIDDLE EAST
ORGANIC COMPOUNDS
ROCKS
SEDIMENTARY ROCKS
TECTONICS
020200* - Petroleum- Reserves
Geology
& Exploration
580000 - Geosciences