Pyroxene poikiloblastic rocks from the lunar highlandsThe results of detailed petrographic, X-ray, electron microprobe, ion probe, and Ar-40/Ar-39 age studies of pyroxene poikiloblastic breccias, an important lunar highlands lithology, are interpreted to indicate that high grade metamorphic recrystallization occurred over wide regions of the moon at about 4.0 G.y. This metamorphism was probably related to a period of high meteorite influx at that time. The temperatures achieved were highly variable but in some cases were sufficiently intense to cause varying degrees of partial melting of the precursor highlands breccias. A complete spectrum of metamorphic grades from only slight recrystallization to virtually complete melting would be expected in such a model. Such a spectrum is observed in the Apollo 16 rocks.
Document ID
19740040096
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Bence, A. E.
Papike, J. J.
Sueno, S.
Delano, J. W. (New York, State University Stony Brook, N.Y., United States)