@article{oai:nipr.repo.nii.ac.jp:00004643,
 author = {Inoue, Mutsuo and Nakamura, Noboru and Kojima, Hideyasu},
 journal = {Proceedings of the NIPR Symposium on Antarctic Meteorites},
 month = {Mar},
 note = {P(論文), In order to examine REE distributions in components of CM chondrites, eight spherical silicate materials (four chondrules [PO, POP and GO], one CAI, two olivine fragments and one unknown inclusion [chondrule?]) were separated from the Yamato (Y)-793321 meteorite, one of the least altered CM2 chondrites, and have been analyzed for REE, Ba, Sr, Rb, K, Ca, Mg and Fe by isotope dilution, together with petrographic examination. The olivine fragments (YO-1,YO-2) (Fo>99%) with rounded metal inclusions show depletion of alkalis (~10^<-2>×CI), low refractory element abundances (Sr, Ba and REE=0.2-0.5×CI) and a fractionated (V-shaped) REE pattern, indicative of solid/liquid partitioning of REE. It is suggested that YO-1 and YO-2 formed from melt. The CAI (YI-5) consisting of olivine, fassaite and euhedral spinel shows no sign of aqueous alteration. It has low alkali (<0.1×CI) and high refractory element abundances (2-20×CI) and indicates a light REE depletion and generally smooth pattern with a light/heavy REE discontinuity. The unaltered PO chondrule (YC-7) shows alkali depletion and unfractionated abundances of REE, Ba, Sr and Ca. The altered PO and GO chondrules (YC-8,YC-38) and unknown spherule (Y-9) indicate a light-REE depleted pattern with a negative Eu anomaly and low Ba, Sr and alkalis (&acd;0.1×CI). This REE fractionation seems to be a new type for a chondrule, indicating that a unique REE fractionation occurred during the formation and/or evolution of the Y-793321 CM meteorite.},
 pages = {150--163},
 title = {A preliminary study of REE abundances in chondrules, an inclusion and mineral fragments from Yamato-793321 (CM2) chondrite},
 volume = {7},
 year = {1994}
}