chondrite

Definitions

  • WordNet 3.6
    • n chondrite a rock of meteoric origin containing chondrules
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Webster's Revised Unabridged Dictionary
    • n Chondrite (Min) A meteoric stone characterized by the presence of chondrules.
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Century Dictionary and Cyclopedia
    • n chondrite A common class of meteoric stones, characterized by large numbers of rather minute spherical crystalline grains. See meteorite.
    • n chondrite A fossil marine plant of the Chalk and other formations: so called from its resemblance to the existing Chondrus crispus, or Irish moss.
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Etymology

Webster's Revised Unabridged Dictionary
Gr. a grain (of wheat or spelt), cartilage

Usage

In literature:

However, studies of the carbon in the carbonaceous chondrites have failed to detect any of these forms.
"Significant Achievements in Space Bioscience 1958-1964" by National Aeronautics and Space Administration
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In news:

Chondrites are primitive meteorites that scientists think were remnants shed from the original building blocks of planets.
In it, Hoover describes the latest findings in his study of an extremely rare class of meteorites , called CI1 carbonaceous chondrites -- only nine such meteorites are known to exist on Earth.
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In science:

The BSE model presents a chemical composition of the Earth similar to that of CI chondritic meteorites see, e.g., (McDonough, 2003; Palme and O’Neill, 2003).
Geo-neutrinos and Earth's interior
Some authors, however, have argued for a genetic relationship of our planet with other chondrites, such as enstatite chondrites, which are richer in long lived radioactive elements (Javoy, 1995).
Geo-neutrinos and Earth's interior
For this last column we assume the chondritic ratio for the masses (Th/U = 3.9), which implies that 79% of the geo-neutrino signal comes from uranium.
Geo-neutrinos and Earth's interior
For this last column we assume the chondritic ratio for the masses (Th/U = 3.9), which implies that 21% of the geo-neutrino signal comes from thorium.
Geo-neutrinos and Earth's interior
Earth global composition is generally estimated from that of CI chondritic meteorites by using geochemical arguments which account for loss and fractionation during planet formation.
Geo-neutrinos and Earth's interior
In this way primitive absolute abundances of elements such as Al, Ca and Ti are determined, a factor about 2.8 times CI chondritic abundances.
Geo-neutrinos and Earth's interior
It is believed, and supported by studies of mantle samples, that refractory lithophile elements inside Earth are in the same proportion as in chondritic meteorites.
Geo-neutrinos and Earth's interior
In this way, primitive abundances of Th and U can be derived by rescaling the chondritic values.
Geo-neutrinos and Earth's interior
It is conceivable that the original material from which the Earth formed is not exactly the same as inferred from CI-chondrites. A model with initial composition as that of enstatite chondrites could account for a present production of some 30 TW (Hofmeister and Criss, 2005a; Javoy, 1995).
Geo-neutrinos and Earth's interior
As a curiosity, an analysis where both N (U) and N (Th) are left unconstrained yields as a best fit N (Th)/N (U) ≈ 5.7, which looks far from the chondritic value ≈ 0.25; however, both values are comfortably consistent with the data already at the 1σ level.
Geo-neutrinos and Earth's interior
This point corresponds to a model with a total uranium mass m(U) = 8 × 1017 kg, an uranium poor crust, mC (U) = 0.3 × 1017 kg, the rest of the uranium being placed at the bottom of the mantle, and global chondritic thorium-to-uranium ratio.
Geo-neutrinos and Earth's interior
A major property of chondrites is the strong similarity of their chemical composition with that of the solar photosphere (Fig. 1) for most elements except the most volatile ones (H, He, C, N and noble gases).
Meteorites and the physico-chemical conditions in the early solar nebula
CG-CAIs underwent high temperature melting in a wind close to the protosun, where they were evaporated at low ambient pressures and underwent slow cooling when transported to the accretion regions of chondrites and terrestrial planets at a few AU (Richter et al. 2002, Shu et al. 1996).
Meteorites and the physico-chemical conditions in the early solar nebula
However, following the discovery of large D excesses in unequilibrated ordinary chondrites (Robert et al. 1979, McNaughton et al. 1981), H isotopes were systematically studied in both hydrated minerals and organic matter in ordinary chondrites (e.g.
Meteorites and the physico-chemical conditions in the early solar nebula
The most primitive IOM is found in CI, CM and CR chondrites and has been extensively characterized in Orgueil and Murchison.
Meteorites and the physico-chemical conditions in the early solar nebula
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