Results 1 to 10 of about 424,190 (218)

Paleomagnetic systematics of ordinary chondrites

Earth and Planetary Science Letters, 1975
The investigation shows that the decrease in intensity and the increase in stability of natural remanent magnetization (NRM) to alternating field (AF) demagnetization roughly parallel the decrease in Ni-Fe metal content and the corresponding enrichment of the metal phases in Ni.
Aviva Brecher, Rambabu P. Ranganayaki
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ASTEROIDAL SOURCE OF ORDINARY CHONDRITES*

Meteoritics, 1985
The orbital evolution of asteroidal fragments with diameters ranging from 10 cm to 20 km, injected into the 3:1 Kirkwood gap at 2.50 A.U., has been investigated using Monte Carlo techniques. It is assumed that this material can become Earth‐crossing on a time scale of 106 years, as a result of a chaotic zone discovered by Wisdom, associated with the 3 ...
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Presolar components in the ordinary chondrites

Earth and Planetary Science Letters, 1990
Abstract As part of the search for presolar material in primitive meteorites eleven ordinary chondrites, ranging from petrologic type 3 to 6, have been analysed for C and N isotopes by stepped combustion. Isotopically anomalous components have been found only in those meteorites of petrologic type 3.6 or below.
C.M.O'D. Alexander, J.W. Arden, R.D. Ash, C.T. Pillinger   +3 more
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Thermoluminescence Study of Ordinary Chondrites

AIP Conference Proceedings, 2009
The mineral responsible for thermoluminescence (TL) in ordinary chondrites is mainly feldspar. Thermal metamorphism transferred feldspathic glass to feldspar. Then induced TL is useful tool for subtype classification in type 3 ordinary chondrites. Natural TL is also useful for identifying potentially paired fragments.
K. Ninagawa, Arnold Gucsik
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Primordial Rare Gases in Unequilibrated Ordinary Chondrites

Science, 1967
The primordial gases of eight unequilibrated ordinary chondrites are strongly fractionated with respect to "cosmic" proportions. The absolute amounts are roughly proportional to the degree of disequilibration. Apparently, ordinary chondrites originally contained considerably larger amounts of primordial rare gases.
D, Heymann, E, Mazor
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Ordinary Chondrites

Ordinary chondrites, the most abundant meteorites, constitute about 80% of meteorite falls and are essential to our understanding of cosmochemistry. They provide important information about planetary accretion, the early Solar System, and the geological history of asteroids, including such processes as thermal metamorphism, shock metamorphism, and ...
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Metamorphism of the ordinary chondrites: A review

Geochimica et Cosmochimica Acta, 1969
Abstract Textural variations among the ordinary chondrites are paralleled by mineralogioal and chemical trends, most of which are consistent with the view that these chondrites have experienced various degrees of alteration in the solid state.
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The matrices of unequilibrated ordinary chondrites: Implications for the origin and history of chondrites

Geochimica et Cosmochimica Acta, 1981
The matrices of 16 unequilibrated chondrites were examined by optical microscopy, an electron microprobe, and a scanning electron microscope. The fine-grained, opaque, silicate matrix of type 3 unequilibrated chondrites was compositionally, mineralogically, and texturally different from the chondrules and their fragments; it may be the low temperature ...
Gary R. Huss, Klaus Keil, G.J. Taylor
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Glass‐rich chondrules in ordinary chondrites

Meteoritics, 1994
Abstract There are two types of glass‐rich chondrules in unequilibrated ordinary chondrites (OC): (1) porphyritic chondrules containing 55–85 vol% glass or microcrystalline mesostasis and (2) nonporphyritic chondrules, containing 90–99 vol% glass. These two types are similar in mineralogy and bulk composition to previously described Al‐rich chondrules ...
Alexander N. Krot, Alan E. Rubin
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Source of potassium in shocked ordinary chondrites

Geochimica et Cosmochimica Acta, 2012
Abstract Argon–argon dating (a variation of potassium–argon dating) of ordinary chondrites is being used to reconstruct the collisional impact history of their parent bodies. However, due to the fine-grained, multi-mineral, highly shocked nature of chondrites, the sources of potassium (K) in these meteorites have not been fully identified.
J.R. Weirich, T.D. Swindle, C.E. Isachsen, T.G. Sharp, C. Li, R.T. Downs   +5 more
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