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The upper cretaceous ophiolite complex of Masirah Island, Oman
Author(s) -
Moseley F.
Publication year - 1969
Publication title -
geological journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.721
H-Index - 54
eISSN - 1099-1034
pISSN - 0072-1050
DOI - 10.1002/gj.3350060211
Subject(s) - ophiolite , geology , obduction , peridotite , gabbro , geochemistry , cretaceous , ultramafic rock , pillow lava , basalt , paleontology , oceanic crust , tectonics , subduction , volcanic rock , volcano
Masirah Island is almost entirely composed of a highly faulted and unmetamorphosed folded ophiolite complex which is unconformably overlain by unfolded Eocene limestone and is correlated with the Upper Cretaceous Semail Complex of the Oman Mainland. The ophiolites include serpentine, basalt, pyroclastics and some radiolarite, and intrusive complexes largely composed of serpentine, peridotite, picrite, anorthosite, gabbro and granite, with transitional varieties. Emplacement structures within the intrusions are extremely complicated, with the gabbros full of blocks mostly of serpentine up to 1 km or more in diameter. There are also late stage veins, lenses and irregular bodies of granite. Ophiolites, probably derived from the mantle, are ultrabasic differentiates with soda metasomatism. Tectonic structures are largely pre‐Eocene. They include fractures, some of which are parallel to the late Tertiary submarine Masirah fault which is related to continental drift.