Oxygen-isotopic compositions of minerals from the Baszkówka chondrite

• Autorzy: Maruyama S.
• Języki publikacji: EN

Abstrakty

EN

Oxygen isotopic compositions of two picotite-bearing chondrules from Baszkówka L5(S1) equilibrated ordinary chondrite have been determined by secondary ion mass spectrometry. The O-isotopic compositions of the minerals in the picotite-bearing chondrules are slightly more 16O-rich than the bulk O-isotopic composition of Baszkówka. The petrological properties and the O-isotopic compositions of these chondrules suggest that they have closer relationship to ferromagnesian chondrules than CAIs. The 16O-enrichment of the picotite-bearing chondrules may result from incomplete O exchange reaction between 16O-rich chondrule precursors and the 16O-poor solar nebular gas. This implies that the picotite-bearing chondrules are more primitive than ordinary ferromagnesian chondrules in Baszkówka. The O-isotopic compositions of the minerals in one of these chondrules relate to the crystallization sequence. These O-isotopic variations of minerals within the chondrule may result from incomplete O exchange between the chondrule melt droplet and the nebular gas. The heterogeneity of the O-isotopic composition in Baszkówka indicates that Baszkówka has not been homogenized completely during thermal metamorphism and/or secondary alteration.

Słowa kluczowe

EN

Baszkówka; meteorites; ordinary chondrites; chondrules; spinel; oxygen isotopes

• Wydawca: Państwowy Instytut Geologiczny - Państwowy Instytut Badawczy
• Czasopismo: Geological Quarterly
• Rocznik: 2001
• Tom: Vol. 45, No 3
• Strony: 303--312
• Opis fizyczny: Bibliogr. 21 poz., fot., tab., wykr.

Twórcy

autor

Maruyama S.

• Institute for Study of the Earth's Interior, Okayama University, Yamada 827, Misasa, Tohaku-gun, Tottori 682-0193, Japan,

Bibliografia

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