Relation between soil-gas radon variation and different lithotectonic units, Garhwal Himalaya, India

Measurements of radon concentration and uranium content in soil and rocks were made in the regions of the Alaknanda and Bhagirathi valleys in the Garhwal Himalaya by using radon emanometry and X-ray fluorescence method, respectively. The data were collected from different lithotectonic units along and across the various regional thrust planes, faults, shears, etc. The observed values were then correlated with the geological formations and structure of the area. Radon concentrations were found to be controlled by lithology, structure and associated uranium mineralization. A positive linear correlation was also observed between soil-gas radon and in situ uranium in the area.