Results 211 to 220 of about 10,798 (236)

Shock metamorphism of carbonaceous chondrites

Geochimica et Cosmochimica Acta, 1992
Shock effects were studied in 69 carbonaceous chondrites, including CM2, CO3, CV3, ungrouped C2-C4, and CK4-6 chondrites, using optical microscopy of thin sections. It is shown that the classification scheme of Stoeffler et al. (1991) for the progressive stages of shock metamorphism in ordinary chondrites is also applicable to carbonaceous chondrites ...
Edward R.D. Scott, Klaus Keil, Dieter Stöffler   +2 more
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The carbonaceous chondrites

Space Science Reviews, 1963
The carbonaceous chondrites are a group of stony meteorites characterized by the presence of an appreciable amount of carbonaceous material other than free carbon (diamond and graphite). They have been divided into three subgroups known respectively as Type I, Type II, and Type III.
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Developing Carbonaceous Chondrite Asteroid Simulants

Earth and Space 2018, 2018
This paper describes the processes and challenges of producing high-fidelity asteroid simulants. DSI (in partnership with UCF) is producing four families of carbonaceous chondrite simulants: CI, CR, CM, and C2. Britt provided target mineralogies, recommendations for researcher safety considerations, and target physical characteristics of selected ...
Covey, S. D., Lewis, J. S., Metzger, P. T., Britt, D. T.   +3 more
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Fluorescent organic matter in carbonaceous chondrites

Advances in Space Research, 1999
Fluorescent organic matter in carbonaceous chondrites was investigated using a microscope equipped with a fluorescence spectrophotometer. Fluorescent particles were observed in powdered CM2 carbonaceous chondrites (Y-74662, Y-7791198, and Murchison) without carbon enrichment by acid treatments. Although it was difficult to find fluorescent particles in
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Noble gases in carbonaceous chondrites

Geochimica et Cosmochimica Acta, 1970
Carbonaceous chondrites noble gases measurement by mass spectroscopy, discussing compositional trends and ...
Emanuel Mazor, Dieter Heymann, Edward Anders   +2 more
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Boron concentrations in carbonaceous chondrites

Geochimica et Cosmochimica Acta, 1978
We have analyzed B in carbonaceous chondrites in order to clarify a factor of 100 difference between the solar system B abundance derived from the solar photosphere and that inferred from previous meteorite data. Consistent results were obtained from two instrumental methods for B analysis: (a) counting of the high energy betas from ^(12)B produced by ...
Weller, Martha Riherd, Furst, Marian, Tombrello, T. A., Burnett, D. S.   +3 more
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Rhenium-Osmium Isotope Systematics of Carbonaceous Chondrites

Science, 1989
Rhenium and osmium concentrations and Os isotopic compositions of eight carbonaceous chondrites, one LL3 ordinary chondrite, and two iron meteorites were determined by resonance ionization mass spectrometry. Iron meteorite 187 Re/ 186 Os and 187 Os/ 186
R J, Walker, J W, Morgan
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Spectral reflectance properties of carbonaceous chondrites: 8. “Other” carbonaceous chondrites: CH, ungrouped, polymict, xenolithic inclusions, and R chondrites

Icarus, 2012
We have analyzed reflectance spectra (0.3–2.5 lm) of a number of ungrouped or tentatively grouped carbonaceous chondrites (CCs), possible CC-type xenoliths in an aubrite (Cumberland Falls) and a howardite (PRA 04401), a CH chondrite (PCA 91467), a CC polymict breccia (Kaidun), and some R chondrites.
E.A. Cloutis, P. Hudon, T. Hiroi, M.J. Gaffey, P. Mann   +4 more
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Organic constituents of carbonaceous chondrites.

Life sciences and space research, 2002
From a brief discussion of forms of meteorite carbon it is concluded that almost all the carbon in the carbonaceous chondrites is present as organic matter. Attempts to extract and identify this organic matter are then reviewed. It is shown that only 25 per cent has been extracted and only about 5 per cent chemically characterized.
M H, Briggs, G, Mamikunian
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Amino Acids in an Antarctic Carbonaceous Chondrite

Science, 1979
Amino acids have been found in aqueous extracts of a C2 carbonaceous chondrite recovered from Antarctica. The composition of the amino acids strongly suggests that they have a meteoritic origin. Comparison of these results with those obtained with other C2 chondrites supports the view that Antarctic meteorites have not been significantly altered by ...
J R, Cronin, S, Pizzarello, C B, Moore
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