A radiometric and geochemical reconnaissance of the Permian outcrop and adjacent areas in south-west England

A radi.ometric and geochemical survey was carried out across the Permian outcrop and adjacent areas in south-west England. It showed an absence of uranium mineralization of a.,y significance except in areas to the north of Exmouth a..~d near Okehampton. In the Permian near Exmouth;well developed· reduction features, with high radiometric -values '(up to 150 μR/h) 1 are accmnpanied "':::ly high t:.ra.""liun values (up to 3~-¥g/1) in bicarbonate-rich waters which suggest th~t.uraniferou.s _nodular horizons may be found at points up to 16km north of the previously know~"l occu..-rence at Littlehaw. _Localized anomalous radioactivity (up to 60 pR/h) occurs at a n~er of sites along the line of the Sticklepath-Lustleigh wrench fault zone between South Zeal and Inwardleigh, with up to 150 pR/h being recorded at one excavated site. Water sampling for uranitun in the bicarbonate-rich environment of the Permian is shown to be of great use. Background ura..~ium and radiometric values are controlled by the provenance of the Permian sediments and generally increase in value towards the area nearest the granite source and where reduced bands are best developed.