Annual report on exploration, EL 453 Rinkabeena, for year ending 27-05-1977

Abstract

During 1976, two drilling programmes totalling 2865 m of rotary percussion and diamond drilling were completed at Rinkabeena, (This was made up of 62 rotary percussion and 7 precollared diamond driliholes). The prospective sandstone horizon within the Mount Eclipse Sandstone was tested along a strike length of 9 kilometres, east and west of the previously discovered mineralization. Almost all holes intersected the prospective unit and were terminated in a shale-siltstone marker bed at the base of the favourable sequence. 8 drill holes intersected uranium mineralization at grades better than 500 ppm U308 over a metre or more. The best result was 3758 ppm eU308 over 1.30 m which was substantially better than any other result. The mineralization was found to occur as carnotite in a strongly oxidized

zone near surface and as uraninite in the unweathered zone below the ground water level. Both types of mineralization appear to be sporadic, generally of low grade, and of limited thickness. The uranium is very close to being in radiometric equilibrium indicating very little transportation of uranium (or radium) in geologically recent time and suggests that the subsurface carnotite mineralization represents an almost in situ oxidation product of primary uraninite. Mineralisation appears to be sporadic and low grade.