Results 171 to 180 of about 690,278 (261)

Phlogopite from the Horoman Ultramafic Rocks

open access: yesPhlogopite from the Horoman Ultramafic Rocks
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Abiotic methane in continental ultramafic rock systems: Towards a genetic model

Applied Geochemistry, 2019
Methane (CH4), often in substantial quantities, is reported for numerous surface manifestations (seeps, springs) and aquifers in continental serpentinized ultramafic rocks, in ophiolites, peridotite massifs and intrusions.
G. Etiope, M. Whiticar
semanticscholar   +1 more source

Lichens and ultramafic rocks: a review

The Lichenologist, 2004
Floristic, vegetational and ecological features of lichens in ultramafic environments are reviewed using a wide range of literature dating from the beginning of the 20th century. Co-presence of acidophytic (silicicolous) and basiphytic (calcicolous) species and the occurrence of species characterized by particular (disjunct) distribution patterns are ...
FAVERO LONGO, Sergio Enrico   +2 more
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Potassium in ultramafic rocks

Geochimica et Cosmochimica Acta, 1953
Abstract Quantitative spectrochemical determinations of potassium in 50 specimens of ultramafic rock confirm the preliminary observation ( Ahrens , Pinson and Kearns , 1952) that the abundance of potassium in this rock type is much lower than has usually been assumed.
W Holyk, L.H Ahrens
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Lunar Ultramafic Glasses, Chondrules and Rocks

Nature Physical Science, 1972
Analysis of all samples returned by lunar missions before Apollo 15 has shown green glasses of ultramafic composition in soil and microbreccia samples. Ultramafic glasses in Apollos 11 and 14 and Luna 16 samples are rare and similar to each other in composition but different from any of the rocks collected at these sites.
T. E. BUNCH   +4 more
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Ultramafic and Related Rocks

1972
The ultramafic rocks are composed mainly of dark-colored mafic or ferro-magnesian minerals such as olivine, pyroxene, amphibole, serpentine, garnet, biotite, and opaque oxides. They are usually, but not always, ultra-basic (having less than 45 percent SiO2).
Gunter Faure, James L. Powell
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Metamorphism of Ultramafic Rocks

1994
Ultramafic rocks are magnesium silicate rocks that normally contain no felsic minerals or very little (
Kurt Bucher, Martin Frey
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Alkali content of alpine ultramafic rocks

Geochimica et Cosmochimica Acta, 1965
The lower limit of abundance of sodium and potassium in ultramafic rocks is less than the threshold amount detectable by conventional analytical methods. By a dilutionaddition modification of the flame-spectrophotometric method, sodium and potassium have been determined in 40 specimens of alpine ultramafic rocks.
Warren Hamilton, Wayne Mountjoy
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