Twinning and Intergrowth of Olivine Crystals in Chondritic Meteorites

R. T. Dodd and Charles Calef1
Department of Earth and Space Sciences, State University of New York at Stony Brook, New York, U.S.A.
1Present address: Department of Geology, Parks Road, Oxford, England.

Summary: The angular relationships among sets of olivine plates in barred chondrules were investigated on the universal stage to test a suggestion that such chondrules represent exsolution and inversion from a pre-existing jadeitic pyroxene. In one of sixty-seven cases studied, adjacent plates represent olivine twinning on (100); the others vary randomly and correspond to neither olivine nor pyroxene twinning. On this basis and from other evidence, we conclude that the mineralogy and texture of barred chondrules are primary and due to rapid crystallization of ultrabasic magma in a low-pressure environment.

Mineralogical Magazine; September 1971 v. 38; no. 295; p. 324-327; DOI: 10.1180/minmag.1971.038.295.06
© 1971, The Mineralogical Society
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