A Preliminary Classification of Yamato Chondrites with Reference to Metal-Sulfide Equilibrium

• Main Authors: Matsueda, Hiroharu, Kano, Hiroshi, Yanai, Keizo
• Language: English
• Published: 1979
• Subjects: Yamato; Antarc*; Antarctica; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/record/1042/files/KJ00000011586.pdf

P(論文) Silicates, metals and sulfides of the Yamato chondrites from Antarctica were analyzed by means of EPMA, and the chemical-petrologic classification was made with the supplement of textural observation by microprobe technique. On the basis of per cent mean deviation of iron contents in olivines and orthopyroxenes, the following chondrites have been identified; one H type equilibrated chondrite; one H and three L type moderately unequilibrated ones; 5 H (?) unequilibrated ones. Three-phase assemblages of kamacite, taenite and troilite are found in moderately unequilibrated chondrites. Cobalt concentrates selectively in kamacite but not in troilite. Nickel partition relationships between metals and sulfides in chondrites suggest the formation of the unequilibrated chondrites at relatively higher temperatures than in the equilibrated ones. departmental bulletin paper