Evaluation of uranium potential of an area using hydrogeochemical exploration techniques - A case study of North Khetri Copper Belt, Rajasthan Kiran Sanku Usha*, Murmu Sushant, Tripathi B.K., Pandey Pradeep Atomic Minerals Directorate for Exploration and Research, New Delhi *E-mail: ushakiransanku@gmail.com
Online published on 13 February, 2019. Abstract Hydrogeochemical studies were carried out over an area of 600 sq km in North Khetri Copper Belt (NKCB) area, Jhunjhunu and Sikar districts, Rajasthan and groundwater samples were collected from 187 borewells exposing the Delhi Supergroup of metasediments of this area. The preliminary statistical studies and spatial correlation of analytical (U, Na +, K+, Mg+2, Ca+2, SO4–2, HCO3–, Cl–, TDS, conductivity and pH) data have indicated four hydro-uranium anomalous zones within Ajabgarh Group metsediments of Delhi Supergroup at Khetri, Karmari ki Dhani, Papurna and Madhogarh areas. Two hydrouranium anomalies are trending NE-SW near Papurna and Karmari ki Dhani area while another trends due NNE-SSW near Madhogarh areas. These are the dominant axial planar cleavage trend of F2 deformation in the area. Water type in the area is mostly mixed in nature and is slightly dominated by alkaline metals (Na and K) in comparison with alkaline earth metals (Ca and Mg). Major cations are distributed as Na+ > Ca2+ > Mg2+ > K+ while that of anions as HCO3−> Cl−> SO42-> CO32-. Ca-HCO3 and mixed Ca-Mg-Cl are the dominant groundwater types in this area. Gibbs ratio plot suggests rock–water interaction as the major contributor to salinity and variation in water chemistry. Majority of groundwater samples indicate negative Chloro-alkaline indices (CAI) suggesting cation–anion exchange reactions, wherein Mg and Ca from water were exchanged with Na and K. All the major anions and cations depict very poor correlation with uranium. However, based on distinctive hydrogeochemical attributes, favourable geology and structure, the areas in the vicinity of Papurna and Karmari ki Dhani near the western contact of the zone of albitisation of the northern parts of Khetri Copper Belt have been identified as potential target areas. Top Keywords North Khetri Copper Belt, Uranium, Hydrogeochemical technique. Top |