Showing papers by "Toshiko K. Mayeda published in 1986"
TL;DR: In this paper, the average Si isotope composition for each class of meteorites is identical, within analytical uncertainties, for the closed-system behavior for this element prior to meteorite accretion.
74 citations
TL;DR: In this paper, the carbon isotopes in these carbonates matched previously published values, and a qualitative inverse correlation among the C2 meteorites between the carbon concentration and δ13C above 700°C suggests that these distinct heavy carbon releases could be actually due to a single heavy carbon component.
51 citations
TL;DR: Oxygen isotopic compositions have been measured on several size fractions of deep-sea spherules of extraterrestrial origin this article, which have an isotopic composition unlike that of any known macrometeorite.
50 citations
TL;DR: The composition and structure of the Guin ungrouped iron meteorite inclusions have been investigated experimentally as discussed by the authors, and the largest silicate inclusion (2 x 4 cm) consists mostly of a shock-melted plagioclase-rich matrix surrounding large, partly melted augite grains.
44 citations
TL;DR: In the early solar system, shergottites, nakhlites, and chassignites formed a unique group, consistent with their having originated in a common parent body as discussed by the authors.
18 citations
TL;DR: The Ragland, New Mexico, chondrite was found in 1978 as discussed by the authors and it consists of a single stone of 12.16 kg that broke into three pieces, and it is moderately weathered and has a pronounced chondritic texture.
Abstract: The Ragland, New Mexico, chondrite was found in 1978. It consists of a single stone of 12.16 kg that broke into three pieces. The stone is moderately weathered and has a pronounced chondritic texture. Bulk composition favors an LL classification, and modal analysis and oxygen isotopic composition are consistent with this. The thermoluminescence sensitivity of 0.056 + or - 0.020 normalized to Dhajala, compositional variability of olivine (mean Fa 18.3, sigma = 10.1) and low-Ca pyroxene (mean Fs 14.6, sigma = 6.7), and Ca concentrations in olivine indicate metamorphic subtype 3.4 + or - 0.1. The isotopically heavy oxygen composition, which is characteristic of subtypes 3.0-3.1, may be a primary characteristic and not a result of weathering. Low concentrations of radiogenic Ar-40 and planetary Ar-36 suggest noble gas loss.
12 citations
01 Mar 1986
5 citations