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Geochimica Et Cosmochimica Acta, 1992 The origin of isolated olivine grains in carbonaceous chondrites has been suggested to be either by direct condensation or by fragmentation of chondrules. In an attempt to resolve this debate, isolated olivine grains in the carbonaceous chondrite ALHA77307 have been studied in detail.
Rhian H Jones
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Nanosized carbon-rich grains in carbonaceous chondrite meteorites
Earth and Planetary Science Letters, 2004Abstract Macromolecular carbonaceous material is common in primitive meteorites. Little information exists on its form and composition, and there are no published data on nanometer-scale chemical and structural variations. Transmission electron microscopy (TEM) studies of CM meteorites reveal abundant, previously unrecognized nanosized carbonaceous ...
Laurence A J Garvie
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On the nature and origin of isolated olivine grains in carbonaceous chondrites
Geochimica Et Cosmochimica Acta, 1977Abstract Many carbonaceous chondrites contain discrete olivine fragments that have been considered to be primitive material, i.e. direct condensates from the solar nebula or pre-solar system material. Olivine occurring in chondrules and as isolated grains in C3(0) chondrites has been characterized chemically and petrographically.
Harry Y Mcsween
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Presolar spinel grains from the Murray and Murchison carbonaceous chondrites
Geochimica Et Cosmochimica Acta, 2003With a new type of ion microprobe, the NanoSIMS, we determined the oxygen isotopic compo- sitions of small (1m) oxide grains in chemical separates from two CM2 carbonaceous meteorites, Murray and Murchison. Among 628 grains from Murray separate CF (mean diameter 0.15 m) we discovered 15 presolar spinel and 3 presolar corundum grains, among 753 grains ...
Ernst Zinner +2 more
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On the origin of isolated olivine grains in type 2 carbonaceous chondrites
Earth and Planetary Science Letters, 1978Two possibilities exist for the origin of aggregates and isolated grains in C2 meteorites: (1) high-temperature phases that condensed directly from a solar nebular gas accumulated as aggregates and single grains on the parent bodies of carbonaceous chondrites and remained unaltered since, or (2) all high-temperature phases in these meteorites are now ...
Edward Olsen, Lawrence Grossman
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Hydrogenation of PAH molecules through interaction with hydrogenated carbonaceous grains.
Phys. Chem. Chem. Phys., 2014Carbonaceous materials contribute to a significant proportion of the interstellar dust inventory. Reactions on such grain surfaces are thought to play important roles in interstellar chemical networks. Of particular importance are reactions involving hydrogen atoms, and pathways to the formation of the most abundant molecular species, H2.
J. Thrower +4 more
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Infrared spectra of carbonaceous chondrites and the composition of intertellar grains
Astrophysics and Space Science, 1975Infrared spectra (7–40 μ) of the carbonaceous chondrites, Cold Bokkeveld, Murray, and Orgueil are compared with phyllosilicate minerals and interstellar grain spectra. Similarities in the position and shape of the silicate feature near 9.8 μ suggest that similar silicate minerals are present in primitive meteorites and the interstellar dust.
A. Zaikowski, R. F. Knacke
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Carbonaceous grain processing in space and in the laboratory
Advances in Space Research, 1999Laboratory simulations of carbonaceous grain processing which occurs in space are fundamental to outline an evolutionary pathway for these particles. We consider the UV spectral changes induced in hydrogenated carbon grains by thermal annealing, UV irradiation and ion bombardment.
V. MENNELLA +6 more
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Primitive Grain Clumps and Organic Compounds in Carbonaceous Chondrites
Nature, 1976WE show here that the physical conditions in prestellar molecular clouds favour the condensation of complex organic polymers, including amino acids, within a matrix of smaller refractory particles. Such composite grain clumps with dimensions exceeding 1 µm could be expelled along with gaseous material in protostellar cocoons, causing the widespread ...
F. Hoyle, N.C. Wickramasinghe
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