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Published January 30, 1970 | public
Journal Article

Petrologic History of Moon Suggested by Petrography, Mineralogy, and Crystallography

Abstract

Opaque mineral compositions indicate that the fugacity of oxygen is approximately 10^(-13) (earth basalts, 10^(-10)). Experiments under reducing conditions suggest that the crystallization range is approximately 1140° to 1070°C. Iron-rich pyroxmangite, fayalite, and hedenbergite occur in microgabbro. Ferropseudobrookite rimmed by ilmenite containing rutile and Cr-spinel lamellae occurs in ferrobasalt. Plagioclase vitrophyres in breccia can explain highland Surveyor VII analysis. We suggest crystal-liquid differentiation of out-gassed convecting moon with growing Fe-rich core, olivine-pyroxene mantle, plagioclase-rich dynamic crust underlain by nonspherical, inversely stratified ferrobasalt. Impact-breaking or convection-thrusting of crust releases fraction rich in Fe and Ti. Scanning electron microscopy of glass balls reveals minute depressions consistent with micrometeorite impact.

Additional Information

© 1970 American Association for the Advancement of Science. Received 4 January 1970. We thank M. Isaacson and D. Johnson for electron microscopy, R. Zechman and O. Draughn for microprobe operation, G. A. Desborough for sulfide standards, the Clayton and Hafner groups for sample cooperation, and R. Banovich, A. Devitt, and I. Baltuska for technical help. We thank J. Warner of NASA for excellent cooperation. Supported by NASA grant NAS 9-8086. We thank NSF (grants G-1658, GA-4420, and GA-1656), ARPA, Union Carbide Corporation, Herz Foundation, and University of Chicago for basic and specific support.

Additional details

Created:
August 23, 2023
Modified:
October 17, 2023