EL 4623 licensee AREVA, as part of its Curnamona Project comprising eight tenements, has been exploring the Callabonna Sub-basin since 2004 for possible economic deposits of buried sedimentary uranium mineralisation that may have formed within Tertiary palaeochannel sands of the Eocene Eyre Formation and Miocene Namba Formation. The south-western part of its project acreage hosts the Erudina Palaeochannel, wherein uranium mineralisation was intersected by the company's drilling carried out during 2007 and 2008. This channel system lies proximal to the fertile primary uraniferous Crocker Well - Mount Victoria basement granite massif, which is thought to be the main source for potential secondary accumulations of dispersing uranium mineralisation. The channel system was intensely drilled in 2008, but the work failed to demonstrate the presence of significant mineralisation. AREVA's later study of the data obtained from its previous drilling and from EM surveys conducted over the Erudina Palaeochannel led it to interpret that the palaeodrainage system was regionally dipping towards the north-northwest, such that it appeared to extend onto the neighbouring Drennan’s Hut and Round Hill tenements. Inspection of new data from a regional airborne EM survey conducted by Geoscience Australia over the Frome Embayment in 2010 confirmed this interpretation, and consequently during 2012 the subject licence became a focus of regional drilling designed to assess areas previously untested and where EM survey responses could not be adequately interpreted. Between 24-27/6/2012 AREVA completed 4 vertical rotary mud exploratory drillholes having a total penetration of 399.5 m within the now relinquished western half of EL 4623, terminating each of them when the Cambrian Balcoracana Formation bedrock was reached. The drilling and downhole geophysical wireline logging results proved disappointing, since the target palaeochannel fluvial sediments do not appear to extend into this part of the licence, and no significant uranium mineralisation was detected. Although beds of sand up to 30 m thick were intersected by the drilling, they are interpreted as sections through barren aeolian dunes, being composed mostly of oxidised and homogeneous sediment with dull, fine-grained and well rounded grains. In view of the diminished prospectivity of the area so drilled, it has been dropped from tenure by AREVA.