Journal ArticleDOI
Demonstration of 26 Mg excess in Allende and evidence for 26 Al
TLDR
In this article, the authors reported the discovery of a large anomaly in the isotopic composition of Mg in a Ca-Al rich chondrule from the Allende meteorite.Abstract:
We report the discovery of a large anomaly in the isotopic composition of Mg in a Ca-Al rich chondrule from the Allende meteorite. This anomaly is manifest independently of instrumental fractionation and is due to an enrichment of about 1.3 percent in ^(26)Mg while the abundances of ^(25)Mg and ^(24)Mg are terrestrial in value. There is a strong correlation in this chondrule between the ^(26)Mg excess and the Al/Mg ratio so that the most plausible cause of the anomaly is the in situ decay of now extinct ^(26)Al (τ_½ = 0.72 × 10^6 yr). Mineral phases extracted from a Ca-Al-rich aggregate have distinct Al/Mg but show identical, small Mg anomalies which are apparent after correction for fractionation (δ^(26)Mg = 0.3%). These data indicate that this aggregate was isotopically homogenized in a high Al/Mg environment after the decay of ^(26)Al had occurred or that some of the Mg anomalies are due to effects other than in situ decay of ^(26)Al.read more
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Sm-Nd isotopic evolution of chondrites
TL;DR: In this paper, it was shown that none of the analyzed meteorite samples deviated more than 0.5 e-units from a 4.6-AE reference isochron and defined an initial 4.5-AE value for CHUR using the Juvinas data of Lugmair.
Journal ArticleDOI
Nucleosynthesis in asymptotic giant branch stars: Relevance for galactic enrichment and solar system formation
TL;DR: In this paper, a review of nucleosynthesis in AGB stars outlining the development of theoretical models and their relationship to observations is presented, focusing on the new high-resolution codes with high accuracy.
Journal ArticleDOI
Early solar system timescales according to 53Mn-53Cr systematics
G. W. Lugmair,A. Shukolyukov +1 more
TL;DR: In this paper, a study of the 53Mn-53Cr systematics in various solar system objects: angrites, eucrites, chondrites, diogenites, pallasites, the Earth and the Moon, and SNC meteorites is presented.
Journal ArticleDOI
Magma oceans in the inner solar system
TL;DR: A review of evidence for magma oceans on planetesimals and planets can be found in this article, focusing on the processes of compositional differentiation in the silicate magma ocean, distribution and degassing of volatiles, and cooling.
References
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Journal ArticleDOI
Condensation in the primitive solar nebula
TL;DR: In this article, the distribution of the major elements between vapor and solid has been calculated for a cooling gas of cosmic composition, assuming that high temperature condensates remain in equilibrium with the vapor, affecting the temperatures of appearance of successively less refractory phases.
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A component of primitive nuclear composition in carbonaceous meteorites.
TL;DR: The oxygen of anhydrous, high-temperature minerals in carbonaceous meteorites is strongly depleted in the heavy stable isotopes 17O and 18O and probably results from the admixture of a component of almost pure 16O.
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The cosmic abundances of potassium, uranium, and thorium and the heat balances of the earth, the moon, and mars.
Journal ArticleDOI
Determination of the age of the elements
TL;DR: In this article, it was calculated that (0.35 plus or minus 0.06) x 10/sup 9/ years elapsed between the time of formation of the elements and the meteorite.
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Interaction of solar and galactic cosmic-ray particles with the Moon
R. C. Reedy,J. R. Arnold +1 more
TL;DR: In this paper, the rates of formation of radionuclides as a function of depth in the moon for bombardments by galactic-cosmic-ray particles and by solar protons were determined semiempirically.