A note on the mineralogy and petrology of the calciphyres near Nanjangud, Mysore, India

Abstract

The calciphyres and granulites near Nanjangud in Mysore were examined in detail in view of the reported occurrence in them of a remarkable assemblage of rare minerals of the Sanidinite fades. A brief field examination disclosed the absence of Gabbrolimestone contacts previously reported. The calciphyres and calc-granulites occur as layers, lenses and nodules in a group of amphibolites and hornblende granulites. Thin sections of these granulites display cataclastic textures indicative of shearing, and crushing. They are found to be composed of minerals characteristic of high grade marbles, and the absence in them of such minerals as larnite, merwinite and spurrite recorded previously, is consistent with the present field observations.