Results 81 to 90 of about 607 (138)

Origin and emplacement of the ophiolite suite: Appalachian ophiolites in Newfoundland

Journal of Geophysical Research, 1971
The ophiolite suite is probably generated by axial plate accretion at oceanic ridges, and by diffuse slow spreading in marginal basins behind and within island arc complexes. The dunite/harzburgite component may represent the highest parts of a depleted upper mantle shell, about 16 km thick, from which a basaltic partial melt (approx.
John F. Dewey, John M. Bird
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Ophiolites and Their Origins

Elements, 2014
Ophiolites are suites of temporally and spatially associated ultramafic, mafic, and felsic rocks that are interpreted to be remnants of ancient oceanic crust and upper mantle. Ophiolites show significant variations in their internal structure, geochemical fingerprints, and emplacement mechanisms.
Y. Dilek, H. Furnes
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Suprasubduction-zone ophiolites: Is there really an ophiolite conundrum?

2008
Suprasubduction-zone ophiolites have been recognized in the geologic record for over thirty years. These ophiolites are essentially intact structurally and stratigraphi- cally, show evidence for synmagmatic extension, and contain lavas with geochemical characteristics of arc-volcanic rocks.
Rodney V. Metcalf, John W. Shervais
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The Ballantrae ophiolite

Geological Magazine, 1973
SummaryThe Ballantrae complex, variously interpreted in the light of plate tectonics, is reappraised on the basis of comparisons with ophiolites of the Newfoundland Appalachians and the southwestern Pacific. All the main components of a typical ophiolite sequence can be recognized although the sequence has been greatly disturbed by post-emplacement ...
W. R. Church, R. A. Gayer
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Oman Ophiolite: The Harzburgite Ophiolite Type

1989
Although the first detailed report on the Oman ophiolite is recent (Reinhardt, 1969), it is now one of the best studied complexes and is often considered to be the best example of ophiolites in the world. It is indeed the largest, with a crescent-shaped extension over 500 km in length and 50–100 km in width (fig.3.1 and 3.2).
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Ophiolite obduction and the Samail Ophiolite: the behaviour of the underlying margin

Geological Society, London, Special Publications, 2003
Abstract Samail ophiolite emplacement has become a type-example for ophiolite obduction. Despite this, problems and controversy remain with respect to the age of high- P metamorphism, the vergence of structures in deformed rocks beneath the ophiolite, the suprasubduction character of the ophiolite and the
D. R. Gray, R. T. Gregory
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Diamonds in Ophiolites

Elements, 2014
Ophiolites are a newly documented host of diamonds on Earth. Abundant diamonds have indeed been separated from peridotites and chromitites of ophiolites in China, Myanmar, and Russia. In addition, diamond grains have recently been discovered in chromite from the Cretaceous Luobusa ophiolite (Tibet) and the early Paleozoic Ray-Iz ophiolite (polar Urals,
J.-S. Yang, P. T. Robinson, Y. Dilek
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Subduction-Zone Ophiolites and Island-Arc Ophiolites

1977
Although it is often said that typical ophiolites show a definite pseudostratigraphic sequence of rocks and occur in ancient subduction zones, most ophiolites showing a typical sequence occur outside subduction zones, and most ophiolites in subduction zones do not show a regular sequence.
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Northern Philippine Ophiolites: Modern Analogues to Precambrian Ophiolites?

2004
Publisher Summary The northern Philippines is a possible modern analogue for some Precambrian greenstone belts. The Philippine islands constitute amateur island arc complex comprising mainly of ophiolites, island arc plutons, volcanics and volcaniclastics, and thick sedimentary basins filled with immature sediments.
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Petrography and Geochemistry of Ophiolites, Ophiolite Clasts and Triassic Volcanics

1985
The previous chapter has documented the fragmentary preservation of the ophiolites: in the ophiolite units, dolerites, basaltic pillow lavas and oceanic sediments occupy most of the surface. Mafic and ultramafic cumulates are of minor areal importance; they consist of more or less serpentinized ultramafics associated with very minor occurrences of ...
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