Radiometric and Sulphur Isotopic Studies on the Sulphide Bodies from the Singhbhum Cu-U Belt, Eastern India

Detailed studies have been carried out by us (Sengupta and Kalvey, 1992: Sengupta et al-, 1995; Boyce et al-, 1995) at vari_ ous locations in the Singhbhum Shear Zone, Bihar, India to understand the nature of uranium and copper mineralisations in this region. Based on our studies on the distribution of uranium and copper in the copper deposits in the Shear Zone, it has been found that the uranium and copper mineralisations are not necessarily closely associated. Though the uranium and copper bearing solutions proceeded along the same shear planes in the soda granites, there was a time gap between the mineralisation of uranium and copper· This is also supported by the geochronolgical data available at present (Rao et al·, 1979, Bhattacharyya, 1992). In the shear zone, uranium seems to be an important byproduct from the copper deposits with uranium in the range of 10- 250 ppm. The sulphur isotopic studies carried out on individual sulphide mineral pairs showed a narrow distribution of 6 S (+3-9 to +6·3 per mil)· This indicates that the Singhbhum copper ores conform well with the strata bound sulphide deposits in volcanic rocks which exhibit typically positive 6 S- Studies, carried so far, has helped in understanding the nature of the uranium and copper mineralisation (Sengupta et al-, 1995: Boyce et al-, 1995) as well as in assaying of the natural radiation background in the Shear Zone (Sengupta and Kalvey, 1992)- It would also be helpful in discovering higher grades of uranium deposits than those presently known in these region.