The application of hydrogeochemical method in uranium exploration - a case study from Barabazar-Manbazar area, Purulia District, West Bengal

Hydrogeochemical exploration were carried out over an area of 700 sq km in Barabazar-Manbazar area of Purulia district, West Bengal, in order to identify target areas for the uranium mineralization. Water samples were collected from 504 borewells in the Singhbhum Group meta-sediments and Chhotanagpur Granite Gneissic Complex (CGGC) including South Purulia Shear Zone (SPSZ). For individual lithological domains, univariate and multivariate statistical techniques were applied to the analytical data on 10 variables, i.e. U, Na+, K+ , Mg+2, Ca+2, SO4-2, HCO3-, CI-, conductivity and pH. Five hydro uranium anomalous zones within CGGC were delineated at Raghunathpur, Tentla, Chepua-Dighi, Bari and Jitujori areas. However, distinct pattern of high uranium values along with uranium/conductivity are observed only in Raghunathpur-Tentla and Chepua-Dighi areas in the proximal tectonized zones of SPSZ. Based on the distinctive hydrogeochemical attributes, and favourable geology and structure, the areas in the vicinity of Raghunathpur-Tentla and Chepua-Dighi in the northern proximal contact of SPSZ, are designated as potential target areas for detailed geological and geophysical exploration. (author)