Geochemistry and Environmental Significance of Banded Garnet Amphibole rock (BGA) Around Naurhiya, Bijawar Group in Sidhi District, Madhya Pradesh

Occurrence of thin but persistent horizons of banded garnet-amphibole-rock (BGA) is reported from the Proterozoic Bijawar or Mahakoshal Group in Sidhi district, Madhya Pradesh. The physical appearance, mineralogy and chemistry of the rock are closely comparable to some metamorphosed manganiferous iron-formations. The rock occurs in association with a sequence of low-grade metasediments, mainly comprising wacke and argillites together with subordinate quartz arenite, banded magnetite quartzite, limestone, tuffs and basic volcanics, which bear similarity with the sediment-hosted Algoma type iron formation. Although there is a broad similarity in the composition of the Bijawar BGA rocks with the known B1F of the world, the former showsan appreciable enrichment in A1₂O₃, MnO, MgO, CaO, Ba, Zn, Co, Ti, Y and V compared to the latter.