Mineral chemistry and geothermometry of chlorites in relation to physico-chemical conditions of uranium mineralization in the central part of the Singhbhum Shear Zone, eastern India

摘要

The Singhbhum Shear Zone (SSZ) in eastern India is one of the major uranium repositories of the country. Some of the important uranium deposits viz., Bagjata, Jaduguda, Bhatin, Narwapahar and Banadungri-Singridungri are juxtaposed in the central part of SSZ. The uranium mineralization in central SSZ is mainly hosted by tourmaline-apatite-magnetite bearing sericite quartz chlorite schist with uraninite being the main radioactive mineral phase. A close spatial relationship exists between uraniferous minerals and chlorite occurrences in central SSZ. Three different types of chlorite assemblages were recognized and their relationship with uranium mineralization was studied in detail to unravel the physico-chemical conditions for precipitation of uranium vis-avis chlorite geothermometry and constrains on the chlorite chemistry.