Oxygen isotopic compositions of chondrules in Allende and ordinary chondritesThe ferromagnesian chondrules in Allende follow a trend in the oxygen three-isotope plot that diverges significantly from the 16-O mixing line defined by light and dark inclusions and the matrix of the meteorite. The trend probably results from isotopic exchange with an external gaseous reservoir during the process of chondrule formation sometime after the establishment of the isotopic compositions of the inclusions and matrix. The Allende chondrules approach, but do not reach, the isotopic compositions of chondrules in unequilibrated ordinary chondrites, implying exchange with a similar ambient gas, but isotopically different solid precursors for the two types of meteorite.
Document ID
19850044381
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Clayton, R. N. (Chicago Univ. Chicago, IL, United States)
Mayeda, T. K. (Chicago Univ. Chicago, IL, United States)
Hutcheon, I. D. (Chicago Univ. Chicago, IL, United States)
Molini-Velsko, C. (Chicago, University Chicago, IL, United States)
Onuma, N. (Chicago Univ. Chicago, IL, United States)
Ikeda, Y. (Ibaraki University Mito, Japan)
Olsen, E. J. (Field Museum of Natural History Chicago, IL, United States)