Previously found indications of sedimentary uranium mineralisation within buried Lower Tertiary sediments of the Billeroo Palaeochannel have been evaluated by the Minad-Teton consortium after they farmed into a 49% interest in the subject EL 109 during 1974. During July-August 1974, contractor Murdoch Geophysics carried out shallow resistivity profiling along nine east-west traverses in the vicinity of Billeroo West Outstation, to try to improve definition of the palaeochannel that had previously been outlined by Pacminex using gravity and drilling methods. This work was successful, defining the extent and depth of the palaeochannel in places formerly having little such control. An additional, tributary channel was defined in the south-western part of the area profiled, which appears to join the main channel immediately west of the outstation. Both channels are incised into uplifted Cambrian sediments on the western flank of the Benagerie Ridge. During October-November 1974, an initial campaign of detailed exploratory/appraisal drilling was undertaken to confirm the channel system distribution and stratigraphy, and to clarify the controls on the setting of the uranium mineralisation. 57 vertical rotary mud drillholes with a total penetration of 7742 m were completed and geophysically logged, which defined a discrete zone of low grade (average 0.18% U3O8) uranium mineralisation. The occurrence has dimensions of approximately 800 m x 150 m x 2 m, and lies at 120 m depth. It was delineated by close-spaced drillholes put down 100 m - 25 m apart. The previous best mineralised Pacminex drillhole, PMX 63a, was washed out and a correlative gamma ray log was obtained from it using the same wireline tool as had been run the other Minad BW drillholes. Following the cessation of drilling, a register surveyor was contracted to accurately locate and level all of the drillholes and gravity and resistivity survey stations in the Billeroo West area, and to establish a base grid with survey points marked out on 200 m centres. This input allowed the recognition that the uranium-mineralised Billeroo channel has an average gradient of 2.5 m/km on Billeroo West, and thus appears to be a tributary of the ?wider Curnamona channel coming from the south-west, which has little or no gradient. During April-May 1975, a follow-up phase of open hole rotary drilling (55 vertical holes for a total penetration of 7126 m) was undertaken to find out the areal extent of the Goulds Dam uranium deposit, by looking for extensions to known palaeochannel uranium mineralisation, and to better determine the local controls on emplacement of this mineralisation. 9 of the drillholes were sited to investigate indications of mineralisation that had earlier been encountered by Pacminex 1.5 km north of the Goulds Dam deposit, as well as 2 km to the south. The additional drilling confirmed that the Goulds Dam uranium occurrence is only a thin, low grade deposit, possibly up to 1 km long and 350 m wide. It lies on the western side but close to the middle of the Billeroo channel, and its boundaries have been affected by past 'seepage' of mineralisation. The drillhole density is still insufficient to allow the calculation of meaningful reserves. Factors controlling the accumulation of uranium at this location are now thought to be: - the presence of pyrite and carbonaeous matter; - the creation of a restricted flow path for uranium-rich groundwaters produced by channel bars and bends; - a close inter-relationship of the geochemical cell redox interfaces present in mineralised sands of Units A, B and C of the Lower Tertiary palaeochannel sediment sequence. From the 1176 m of stepout drilling undertaken elsewhere within the Billeroo Palaeochannel, only isolated and modest grade uranium occurrences were revealed on the sides of the channel, formed only within attenuated sections of the basal Unit A (the probable principal aquifer). Evaluation of the economic significance of the Goulds Dam deposit, and of the exploration potential of the Billeroo West palaeochannel system, is presently ongoing.