Tenements E53/1601, 1603 and 1604 cover the entire length of the Kukabubba palaeochannel, which has been delivering uranium into the Lake Way system for millennia. Triggers for uranium precipitation within the channel could include changes in the chemistry of groundwater at the confluence with tributary channels, such as the channel which joins the Kukabubba palaeochannel just before it enters Lake Way (see figure). This confluence location is associated with a radiometric anomaly. This anomaly has been partly tested by broad spaced historical drilling that indicates that the source of part of the anomaly is uranium mineralised calcrete. Once tenure has been granted the extent of the mineralisation at the confluence location will be determined by drilling, with the objective of defining an initial resource. In addition, a reconnaissance surface geochemical survey will be carried out along the remaining (upstream) section of the palaeochannel in order to test other identified radiometric anomalies for the presence of uranium.
Ratios of the radioelements can assist with identifying potential uranium deposits. Wyborn et al (1994#) showed that alteration zones associated with Coronation Hill-style mineralisation have slightly elevated uranium, but are strongly depleted in thorium compared to the surrounding rocks that have high levels of both uranium and thorium. The square of the uranium value over the thorium value (U2/Th) proved effective in highlighting uranium mineralisation in the Pine Creek area in the Northern Territory.
The U2/Th ratio has also been shown to be effective in separating primary uranium, associated with uranium-bearing granites, from secondary uranium associated with palaeochannel calcrete such as at Yeelirrie in Western Australia (Wilford et al 2009*). This is because U is mobile relative to Th during weathering. High U2/Th ratio
Tenement E53/1600 straddles the divide between the Kukabubba palaeochannel and another palaeochannel that flows north into Lake Gregory. There is a distinctive radiometric anomaly in the upper reaches of this palaeochannel, covered by tenement E53/1602, that has never been drill tested (Figure 4). Once tenure has been granted a surface geochemical survey will be carried out along the length of the palaeochannel in order to confirm the presence of uranium mineralisation and to identify targets for drilling. Drilling will be constrained by geophysical surveying.
Values are associated with many secondary uranium deposits in Australia, and have highlighted new areas of potential mineralisation.
* Wilford J, Worrall, L & Minty B. 2009. Radiometric Map of Australia provides new insights into uranium prospectivity. AusGeoNews September 2009 Issue No. 95.
# Wyborn LAI, Jagodzinski EA, Morse MP, Whitaker A, Cruickshank BI & Pyke JG. 1994. The exploration signature of the Coronation Hill Gold, Palladium and Platinum deposit. The Australasian Institute of Mining and Metallurgy, Publication Series 5:94
Tenement E53/1247 south-west of Lake Way is strategically postioned between the Dawson-Hinkler uranium deposit immediately to the west (upstream), and the Abercromby Well, Millipede and Centipede uranium deposits immediately to the east (Figure 2). The Centipede deposit has Resource (Measured, Indicated and Inferred) of 11.32 Mt @ 493 ppm U3O8 for 12.3 Mlb contained U3O8 (at a 200 ppm U3O8 cut off (ASX: TOE Release 10 October 2011)) and the Dawson-Hinkler deposit has an Inferred Resource of 13.07 Mt @ 312 ppm U3O8 for 8.98 Mlb contained U3O8 (at a 200 ppm U3O8 cut off (ASX: TOE Release 10 October 2011)). Historic drilling on the western portion of the Zeus tenement confirms continuation of uranium mineralisation eastwards from the Dawson-Hinkler deposits. The eastern portion has yet to be drill tested, but a strong radiometric response over this area suggests the presence of uranium mineralisation. This tenement has been granted and a ground gravity survey was completed in mid 2012. The data, which is yet to be interpreted, will be used to plan a targeted drilling programme. Drilling will commence as soon as heritage clearances have been completed.
The Yeelirrie South Project is located in the north-east Yilgarn Craton in the lower reaches of the palaeochannel that hosts the world-class Yeelirrie uranium deposit (144.5 Mlb contained U3O8 (TSX: CCO Release 26 August 2012)) (Figure 2). Tenements E36/735 and E36/733 cover sections of the palaeochannel downstream from the Yeelirrie deposit, and immediately west and east of the Little Well uranium deposit. The Little Well deposit was discovered in the early 1970s, when percussion drilling returned significant intercepts including 1.5 m @ 819 ppm U3O8 and 6.1 m @ 326 ppm U3O8 at or near the top of a calcrete horizon. The discovery of Little Well confirmed the prospectivity of the lower reaches of the Yeelirrie channel, however, parts of the channel adjacent to Little Well and within the Zeus tenements have not yet been adequately drill tested. A ground gravity survey was carried out over the Yeelirrie South tenements in mid-2012. The data acquired will be used to target drilling that will commence once heritage clearances have been completed.