Prehnite and Pumpellyite in the Archaean Sitagota Volcanics near Deori, Bhandara District, Maharashtra

In this communication we report for the first time the occurrence and microprobe analyses of prehnite and pumpellyite in amygdules of metabasalt from Karu Pahar near Deori, Bhandara district, Maharashtra. The metabasalt belongs to the Sitagota Volcanics of the Late Archaean Khairagarh Group of the Dongargarh Supergroup. Pumpellyite occurs as fibrous aggregates, lining or filling amygdules, whereas prehnite occurs sporadically in amygdules as clusters of tiny prismatic crystals. Pumpellyite is iron-rich, between 10.3 and 13.1 wt% Fe₂O₃ Chlorite is found in close association with pumpellyite in a few of the amygdules. The absence of zeolite, and the presence of prehnite and pumpellyite in the Sitagota metabasalt indicate prehnite-pumpellyite facies metamorphism.