Commenting on the discovery, Russell Penney, managing director said, “We are excited by the discovery, given the 3km length of the structure, the early indicators of high grade uranium mineralisation and its location near to the 20.6 Mlb U3O8 Bigrlyi deposit. As such, this is potentially the most significant discovery of mineralisation made to date by UXA”.
High uranium concentrations detected across three kilometer structure length
The discovery comes on the back of an airborne radiometric survey in 2007 which identified two anomalies (Anomaly A and Anomaly B). In late 2008, UXA drilled at Anomaly A which lies 3km south of Anomaly B, and discovered some narrow zones of uranium mineralization (best 1m at 208 ppm U3O8).
Recent geological mapping has identified radiometric Anomaly B to be due to an east northeast striking uranium bearing fault zone within granite and aplite of the Mesoproterozoic age Southwark Granitic Suite, part of the Arunta Inlier.
The structure has been traced for a distance in excess of 3km and varies in width from 30cm to 12m, averaging 3m. Uranium appears to be associated with ironstone and grades are highly variable from trace up to 4,120 ppm U3O8. Uranium mineralisation is poddy along strike and highly variable across strike.
Uranium values were measured in the field using an appropriately calibrated portable Niton XL3t XRF unit. Values in Table 1 are the maximum uranium values recorded for any single location (point). Scintillometer and XRF readings were taken at 185 points along the structure. Of these 96 points recorded XRF uranium values of between 100 ppm U and 500 ppm U and 12 points recorded values between 500 ppm U and 3,500 ppm U (4,120 ppm U3O8).
High uranium concentrations up to 389 ppm U3O8 have also been recorded within aplite (a type of fine grained granite), located north east of the mapped structure and this provides a potential target to drill a broader zone of mineralization.
The company will follow up this discovery and initial field work with a detailed surface radiometric, field XRF and geochemical sampling program over the fault structure and adjacent anomalous aplite. This work will lead to a drilling program later in 2009.