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Lunar Ultramafic Glasses, Chondrules and Rocks
Nature Physical Science, 1972Analysis 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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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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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
1994Ultramafic 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, 1965The 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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Fossilized Life in Subseafloor Ultramafic Rocks
Geomicrobiology Journal, 2018Ultramafic rocks are hypothesized to support a subseafloor hydrogen-driven biosphere because of extensive production of bioavailable energy sources like H2 or CH4 from fluid-rock interactions.
M. Ivarsson +4 more
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Aragonite from deep sea ultramafic rocks
Geochimica et Cosmochimica Acta, 1980Abstract Aragonite mineralization was observed in serpentinized peridotites from the Romanche and Vema Fracture Zones in the Atlantic and the Owen Fracture Zone in the Indian Ocean, either in veins or as radial aggregates in cavities within the serpentinites. Evidence of incipient dissolution of the aragonite crystals was observed in one case.
E. Bonatti +3 more
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Geotectonic significance of ultramafic rocks
Earth-Science Reviews, 1973Abstract Ultramafic rocks can be divided into 5 principal geotectonic groups, as follows: (1) Layered gabbro-norite-peridotite masses, commonly associated with all ages of terrane, possibly connected with accretionary plate margins. (2) Concentrically zoned Alaska-type bodies, possibly associated with consuming plate margins. (3) Ultramafic lavas and
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Hydrogen Production from Mafic/Ultramafic Rocks
SPE Annual Technical Conference and ExhibitionAbstract Hydrogen is a clean fuel which can be burnt without any carbon emissions. To minimize greenhouse gas emissions, humanity would need a significant amount of hydrogen as a fuel. The goal of this work is to understand the mechanisms of geological production of hydrogen in mafic and ultramafic rocks.
K. Panthi, C. V. Oeiyono, K. K. Mohanty
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Metasomatic Alteration of Ultramafic Rocks
1989Metasomatized ultramafic rocks from the 3800 Ma Isua supracrustal belt have been preferentially enriched in calcium, aluminium and silica, but show no or only little addition of potassium and rubidium. This unusual geochemical response to fluid infiltration can be explained in the light of a low buffered activity of aqueous silica during progressive ...
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On the Origin of Ultramafic Rocks
Geological Society of America Bulletin, 1971It is argued that most alpine ultramafic bodies originated as cumulates in basic magma chambers high in the crust. From some of these chambers, magmas were intruded upward or extruded, leaving sill-like ultramafites behind. These were subsequently folded or dismembered by faulting, and, because of their high density, subsided during tectonism, to form ...
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