Evaluation of uranium potential of an area using hydrogeochemical exploration techniques - a case study of North Khetri copper belt, Rajasthan

North Khetri Copper Belt (NKCB) is well known for hosting polymetallic mineralization (Cu±Mo±U±Au±Ag±Co±Fe+REE Mo, Zn, Pb) with complex geological history, multi-episodic deformations and polymetamorphic imprints. The rocks exposed in this terrain belong to Mesoproterozoic Delhi Supergroup. Quartzite, schist, phyllite and metacarbonate rocks of Delhi Supergroup together with granites, amphibolites and pegmatites of post-Delhi intrusives, form the ancillary aquifers in the area. Ground water occurs under unconfined condition in the weathered mantle (ranging in thickness from 10 to 25 m) and under unconfined to semi-confined conditions in deep seated secondary porosity i.e. fractures, joints and contacts of hard rock formations. Hydrogeochemical technique in uranium exploration programme plays a vital role in quick appraisal of an area, especially in soil covered sectors, by utilising rapid and accurate analytical methods of direct measurement of uranium upto ppb level in natural water. An area of 600 sq km in the North Khetri Copper Belt (NKCB) area, Jhunjhunu and Sikar districts, Rajasthan was subjected to hydrogeochemical studies to identify the potential target zones for uranium exploration