- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
Chemical and optical data for 18 pyroxene pairs from granulite facies rocks from India (Madras charnockite), Scotland (Scourie gneiss), and other localities are plotted and compared. Compositions and tie-line trends derived from optical data are shown to be unreliable. It is therefore concluded that the granulite facies should not be subdivided on such a basis.