Application of soil radon and trace element geochemistry for uranium exploration at Kuchanapalle, Guntur district, Andhra Pradesh

A radioactive fault breccia zone trending N30 degrees E is exposed intermit tently within the Ipuru granite dome, near Kuchanapalle village in the NE m argin of Cuddapah basin. A major part of the fault zone is under soil cover . Within this fault zone, a dark coloured ferruginous and uraniferous fault breccia is exposed over an area of 150m x 2.5m. In order to trace the cont inuity of the concealed fault zone, the uraniferous breccia zone was tested by closed circuit soil-gas radon (CCT) measurement, solid state nuclear tr ack detection (SSNTD) survey, and trace element analysis of augur-hole soil samples. Radon levels in 164 anger holes vary from 9 to 863 per 50 sec. Th e alpha track density on cellulose nitrate films used in SSNTD surveys vari es from 27 to 820 per so. mm. The iso-alpha track density map has confirmed the anomalous patterns obtained by the soil-radon survey. Trace element data of soil samples have been processed using R-mode factor analysis of correlation matrix. These data along with radon and SSNTD surve ys have thus been found to be very effective in delineating the extension o f the radioactive breccia zone under soil cover, up to 1200 m towards north .