Results 151 to 160 of about 535 (200)

Formation of ordinary chondrites

Reviews of Geophysics, 1972
Most of the chemical and mineralogical properties of the ordinary chondrites were established by processes that occurred in the solar nebula during a short time span near the time of formation of the solar system. Four separate and distinct fractionation events appear to have been involved in their formation from more primitive material of mean solar ...
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Trapped xenon in ordinary chondrites

Journal of Geophysical Research: Planets, 1992
A trapped component of heavy noble gases representing a distinct solar system (presumably asteroid belt) reservoir is known to be concentrated in carbonaceous carriers of chondritic meteorites. The isotopic signature of trapped Xe in separates of the H4 chondrite Forest Vale (FV) was determined by combusting its carrier phases at 600°C in oxygen ...
Lavielle, B., Marti, K.
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VUGS IN ORDINARY CHONDRITES

Meteoritics, 1981
Large vugs occur in the ordinary chondrite, Farmington. They contain the same phases present in the body of the meteorite, either as vug wall lining or as crystals attached to linings. The morphologies of these phases indicate a history of melting and vapor deposition.
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A survey of the unequilibrated ordinary chondrites

Geochimica et Cosmochimica Acta, 1967
Abstract The iron contents of olivines and low-calcium pyroxenes in thirty-one ordinary (H-, L- and LL-group) chondrites were determined by microprobe analysis. Twenty-five of these contain inhomogeneous silicates and are, in this respect, unequilibrated.
R.T. Dodd, W.R.Van Schmus, D.M. Koffman
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Accretion of the ordinary chondrites

Earth and Planetary Science Letters, 1976
Abstract The narrow size distributions of silicate and metal particles in 19 unequilibrated ordinary chondrites and other textural properties of these meteorites strongly suggest that chondritic material was sorted before or during its accumulation in parent bodies.
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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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Carbon in the matrices of ordinary chondrites

Meteoritics, 1993
Abstract— Carbon in the petrologic matrices of a number of ordinary chondrites of groups H, L, and LL, and of types 3 through 6 was studied with a nuclear microprobe and a Raman microprobe. The majority of the matrices had carbon contents in the narrow range between 0.03 and 0.2 wt%. The carbon content decreased only slightly with increasing petrologic
J. Makjanic, R. D. Vis, J. W. Hovenier, D. Heymann   +3 more
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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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Actinide abundances in ordinary chondrites

Geochimica et Cosmochimica Acta, 1990
Measurements of ^(244)Pu fission Xe, U, Th, and light REE (LREE) abundances, along with modal petrographic determinations of phosphate abundances, were carried out on equilibrated ordinary chondrites in order to define better the solar system Pu abundance and to determine the degree of variation of actinide and LREE abundances.
Hagee, B., Bernatowicz, T. J., Podosek, F. A., Johnson, M. L., Burnett, D. S., Tatsumoto, M.   +5 more
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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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