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MINERALOGY AND CHEMISTRY OF THE ASHMORE CHONDRITE
Author(s) -
Bryan W. B.,
Kullerud G.
Publication year - 1975
Publication title -
meteoritics
Language(s) - English
Resource type - Journals
eISSN - 1945-5100
pISSN - 0026-1114
DOI - 10.1111/j.1945-5100.1975.tb00006.x
Subject(s) - chondrite , chromite , chondrule , meteorite , olivine , silicate , electron microprobe , geology , mineralogy , geochemistry , plagioclase , mafic , mineral , matrix (chemical analysis) , chemical composition , astrobiology , chemistry , quartz , physics , organic chemistry , paleontology , chromatography
The Ashmore olivine‐bronzite chondrite is a group H, type 5 stone which differs from other H5 chondrites mainly in its higher proportion of chromite (0.9 wt %) and in the relatively lower iron and higher magnesium content of the chromite. The modal proportions of opaque phases were obtained by point‐counting in reflected light, and the modal proportions of nonopaque silicate phases in the matrix were estimated from traverses of a selected small area by electron microprobe. The consistency between the bulk chemical analysis and the chemical composition calculated from the modal mineral proportions implies that the bulk silicate composition of the chondrules is very similar to that of the silicate matrix and suggests a common source for both chondrules and matrix.