Pyroxene-spinel intergrowths in lunar and terrestrial pyroxenesThe paper describes the oriented intergrowth of spinel and pyroxene in a pigeonite from Luna 20, an augite from Apollo 16 anorthosite 67075, and an orthopyroxene from a spinel lherzolite nodule from the San Quintin volcanic field, Mexico. Using Mo K alpha radiation, photographs were taken of small, hand-picked single-crystals. A mechanism of exsolution is suggested in which the oxygen framework remains intact and spinel nuclei are formed by the migration of cations from interstitial sites and tetrahedral sites in the original non-stoichiometric pyroxene.
Document ID
19770051908
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Okamura, F. P. (Washington Univ. Seattle, WA, United States)
Mccallum, I. S. (Washington Univ. Seattle, WA, United States)
Stroh, J. M. (Washington Univ. Seattle, WA, United States)
Ghose, S. (Washington, University Seattle, Wash., United States)