GRANULITES OF BHOPALPATNAM AND KONDAGAON BELTS, BASTAR CRATON, MP - PETROLOGICAL AND FLUID INCLUSION STUDIES

The Bhopalpatnam and Kondagaon granulite belts (BGB, KGB) occur surrou nding the Bastar craton of central India. This paper deals with the ge ology, mineralogy and the fluid characteristics of these two belts. Th e geology of the two belts indicate that they abound in metasedimentar y swathes. The metamorphic P-T conditions of the BGB range from 6 to 9 kbar at temperatures of 750 degrees C, whilst those of the KGB vary f rom 4 to 6 kbar at temperatures of 700 degrees C. The BGB shows an IBC path, while the KGB exhibits a dominant ITD path. These trends, based on mineral chemistry, are corroborated by fluid-inclusion studies. Th e lithologies of the BGB exhibit high-density CO2 inclusions that repr esent the remnants of peak metamorphism. In contrast, the CO2 inclusio ns of the KGB are of low density, indicative of post-peak conditions. The studies suggest that the CO2-rich fluids may not have come from th e supracrustal sediments. An external source, possibly underplated bas alt, could have supplied the heat and the supercritical fluids. Based on lithological similarities, it can be stated that the BGB is an exte nsion of the late Archaean Karimnagar granulite belt. The important pr oblem which is still to be solved is the junction of the late Archaean BGB with the Eastern Ghats granulite belt. Copyright (C) 1996 Elsevie r Science Ltd