Results 201 to 210 of about 32,577 (247)

The Bencubbin chondrite breccia and its relationship to CR chondrites and the ALH85085 chondrite

Meteoritics, 1990
Abstract— Bencubbin is an unclassified meteorite breccia which consists mainly of host silicate (∼40 vol.%) and host metal (∼60%) components. Rare (< 1%) ordinary chondrite clasts and a dark xenolith (formerly called a carbonaceous chondrite clast) are also found.
Michael K. Weisberg, Martin Prinz, Cherukupalli E. Nehru   +2 more
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Oxygen isotopes in R-chondrite magnetite and olivine: links between R chondrites and ordinary chondrites

Geochimica et Cosmochimica Acta, 2000
Ion-microprobe studies yield Δ17O (=δ17O − 0.52 · δ18O) values in magnetite from the Rumurti chondrite (RC) PCA91241 (which is paired with PCA91002) of +3.1 to +3.9‰, slightly higher than that in O from whole-rock R samples. Despite Δ17O values in whole-rock RCs that are much (by ca.
James P Greenwood, Alan E Rubin, John T Wasson   +2 more
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Feldspar in Chondrites

Science, 1965
Whereas most chondrites contain sodic plagioclase (or occasionally maskelynite, its glassy equivalent), a few are free of feldspar. Absence of plagioclase is correlated with the presence of calcium-poor clinopyroxene (pigeonite sensu lato ) instead of orthopyroxene.
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Chainpur-like Chondrites: Primitive Precursors of Ordinary Chondrites?

Science, 1966
Chainpur and similar, apparently primitive, chondritic meteorites may be precursors of ordinary chondrites; a variety of evidence supports this working hypothesis. In general, carbonaceous chondrites seem to be related collaterally to this genetic sequence rather than being direct ancestors of ordinary chondrites.
R A, Schmitt, R H, Smith, G G, Goles
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Amino acids in carbonaceous chondrites

Origins of Life, 1974
For almost 20 years laboratory experiments have advanced the concepts of chemical evolution, particularly with regard to formation of the amino acids. What has been generally lacking is concrete natural evidence for this chemical evolution hypothesis.
J G, Lawless, E, Peterson
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The compositional classification of chondrites: III. Ungrouped carbonaceous chondrites

Geochimica et Cosmochimica Acta, 1982
Abstract Seven carbonaceous chondrites (Allan Hills A77307, Adelaide, Al Rais, Coolidge, Grosnaja, Karoonda and Renazzo) with uncertain classifications were analyzed by instrumental and radiochemical neutron activation analysis for 29 elements: Na, Mg, Al, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, Ga, Ge, As, Se, Br, Ru, Cd, Sb, La, Sm, Eu, Yb, Lu, Os ...
Gregory W. Kallemeyn, John T. Wasson
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THE TAMBAKWATU CHONDRITE

Meteoritics, 1981
According to its petrography, uniform olivine, Fa23.8, and pyroxene, Fs20.4, a total iron content of 22.9 wt % Fe, 16.4 wt % FeO and an FeO/FeO + MgO ratio of 24.7 mol %, the Tambakwatu is a veined, intermediate hypersthene (Cia) or L6 chondrite.
K. Fredriksson, J. Miller, J. Nelen, S. Darsa   +3 more
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Gallium in chondrites

Geochimica et Cosmochimica Acta, 1956
Abstract Chondrites have uniform gallium contents; the average of nineteen samples is 5.3 p.p.m. Ga, with the range 4.2–6.8 p.p.m. Composites of these contain an average of 3.2 p.p.m. Ga in the silicate phase, 15 p.p.m. in the metal phase, and 12 p.p.m. in the sulphide phase.
Hiroshi Onishi, E.B Sandell
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Mercury in chondrites

Journal of Geophysical Research, 1967
The Hg abundance has been determined in chondritic meteorites by neutron activation and separation by volatilization over a series of temperatures ranging from 110° to 1200°C. Hg is highly fractionated between classes of chondrites and within the classes themselves.
G. W. Reed, S. Jovanovic
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