Formation and emplacement ages of the Masirah ophiolite, Sultanate of Oman
- University Innovation Centre, Swansea (England)
- Clyde Petroleum plc, Herefordshire (England)
- Amoco Production Co., Houston , TX (USA)
- Univ. of Leeds, Yorkshire (England)
Hornblende separates from gabbros and biotite separates from crosscutting potassic granites of the Masirah ophiolite have been analyzed by conventional K-Ar techniques. The gabbros have Late Jurassic-Early Cretaceous ages (126-158 Ma), and the granites have broadly similar ages (124-146 Ma). Because the gabbros are likely to give ophiolite formation ages and the granites ophiolite emplacement ages, it can be concluded that the Masirah ophiolite was emplaced very soon after formation. The Late Jurassic-Early Cretaceous ages contrast with the middle Cretaceous ages (90-95 Ma) of the Semail ophiolite, confirming earlier suggestions that the Masirah ophiolite cannot simply be a right-laterally displaced fragment of the Semail ophiolite, but is instead an uplifted block of Indian Ocean crust. The formation and emplacement of the Masirah ophiolite are discussed in the context of the late Mesozoic evolution of the western Indian Ocean.
- OSTI ID:
- 5667595
- Journal Information:
- Geology; (USA), Vol. 19:5; ISSN 0091-7613
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GEOLOGIC FORMATIONS
AGE ESTIMATION
OMAN
ARGON ISOTOPES
BIOTITE
CRETACEOUS PERIOD
GABBROS
GEOLOGIC HISTORY
GRANITES
GROUND UPLIFT
HORNBLENDE
INDIAN OCEAN
ISOTOPE DATING
JURASSIC PERIOD
OCEANIC CRUST
ORIGIN
POTASSIUM ISOTOPES
TECTONICS
ALKALI METAL ISOTOPES
AMPHIBOLE
ASIA
DEVELOPING COUNTRIES
EARTH CRUST
GEOLOGIC AGES
IGNEOUS ROCKS
ISOTOPES
MESOZOIC ERA
MICA
MIDDLE EAST
MINERALS
PLUTONIC ROCKS
ROCKS
SEAS
SILICATE MINERALS
SURFACE WATERS
580000* - Geosciences