Study of the metamorphic manganese ores of Bharweli Mine-area, Madhya Pradesh, India, and their genesis

Abstract

Manganese deposits of the Bharweli area are conformable with the enclosing Precambrian quartzites, phyllites, and sericitic and garnetiferous mica schists and were formed by metamorphism of manganiferous sediments interbedded with pelitic and psammitic rocks. Braunite (two generations) and hollandite are the most abundant minerals; bixbyite, manganite, and secondary pyrolusite and cryptomelane are also present. Braunite of the first generation crystallized earliest, under conditions of increasing metamorphism and deformation. Bixbyite crystallization apparently commenced at the peak of metamorphism and continued after deformation had ceased. Second-generation braunite, manganite, and hematite formed in waning stages of metamorphism.