In a search for possible economic roll-front sedimentary uranium deposits thought to be hosted by Middle Eocene Pidinga Formation fluvial and lacustrine terrestrial sediments deposited in the eastern Eucla Basin, 13 scout RAB/RC open holes were drilled for a total penetration of 2188 feet, and geophysically logged. No uranium mineralisation was encountered in the target sands; maximum downhole gamma log readings were 180 counts per second, corresponding to a 3 feet thick lignitic bed intersected in hole ODH/13a, and 95 cps associated with a micaceous siltstone drilled in hole PDH/01. Analytical studies made on radioactive surface sediment grab samples collected in the Pidinga Lakes concluded that secondary uranium has been completely leached out of the target horizon, which is now oxidised at every site tested by drilling. The highly anomalous radioactivity present in lateritic weathered exposures of the target horizon is due to short-lived decay isotopes of radium-226, as demonstrated in laboratory analyses of four samples taken for study. Hence it is considered that there is a low probability of finding an economic uranium occurrence on the licence area, although untested Tertiary sediments lying further to the east and the west may have potential to retain reduced sequences.