Uranium Projects
Yarrabubba and Quinns Lake Projects: Uranium and Nickel-Copper
These two projects comprise adjacent tenement holdings with different ownership structures, and with common exploration potential for deposits of nickel-copper-PGM's and uranium oxide. The projects are 600 kilometres north-north east of Perth in the Archaean Yilgarn Craton of Western Australia, about 70 kilometres from the mining centre of Meekatharra.
The projects are prospective for Sudbury-style World Class nickel-copper-PGM deposits and contain part of the Nowthanna calcrete-hosted uranium oxide deposit.
The Yarrabubba Project comprises the largest tenement holding, in which Impact has a 30% interest (reducing to 20%). This is a contiguous block of seven exploration licences, with a combined area of 1,320 square kilometres: E51/1072, E51/1073, E20/563, E20/564, E20/565, E20/566 and E20/567. These seven exploration licences are in a joint venture called the YB Nickel Joint Venture with CITIC Resources Australia Pty Ltd, part of the international CITIC Group (known formerly as the China International Trust and Investment Corporation) and four prospectors. CITIC is funding exploration and has earned a 40% interest in the project by spending $250,000. The prospectors hold the remaining 30% interest. CITIC have committed to earning a further 20% in the Project by spending $220,000 and when they have done this the Company's share will reduce to 20%.
The Quinns Lake Project, adjacent to and north west of the Yarrabubba Project, comprises the exploration licence E51/1075, with an area of 45 square kilometres (Impact 100%).
The Nowthanna Uranium Deposit
The Quinns Lake and Yarrabubba project areas were explored in the 1970's and the 1990's for deposits of calcrete-hosted
uranium oxide. Five prospects were identified, including Cogla Downs and Nowthanna. All of these occur within
valley calcretes and clays associated with ancient and modern drainage channels. Historic estimates of tonnes and grade were
made in the 1970's at the Nowthanna and Cogla Downs Prospects. In the late 1990's, following a significant drilling program at Nowthanna, both a geostatistical block model and a polygonal model were used to calculate historic resource estimates. At a
cut-off grade of 200 ppm the Nowthanna deposit contains an Inferred Resource of 10.4 Mt of uranium oxide at an average grade
of 450 ppm for a total of 4,700 t of contained uranium oxide. This has been calculated in accordance with the 2004 JORC Code.
The mineralisation occurs at depths of less than a metre to at least 20 metres and has similar geological characteristics to the Lake Way and Centipede Deposits at Wiluna and owned by Nova Resources Limited and the Lake Maitland Deposit near Sandstone owned by Redport Limited, a wholly owned subsidiary of Mega Uranium Limited. Bench scale metallurgical test work on the Nowthanna mineralisation showed that alkaline leach would be suitable and that further large scale test work is warranted.
Parts of the Nowthanna Uranium Deposit occur in the Quinns Lake Project (E51/1075, Impact 100%) as well as in the YB Nickel Joint Venture tenements (Impact 30% reducing to 20%). The mineral resource estimate generated in 1998 by Snowden has been further reviewed by Snowden at Impact's request. Snowden has concluded that there is an Inferred Resource of uranium oxide mineralisation which may be reported and classifi ed in accordance with the 2004 JORC Code present at Nowthanna. Snowden has calculated that the portion of the resource attributable to Impact (100% of the Quinns Lake Project tenement and 20% of the Yarrabubba Project tenements) at a cut-off grade of 0.2 kg/t uranium oxide is 3.92 Mt at 0.45 kg/t uranium oxide. This represents a contained metal content of 1,780 t of uranium oxide (about 4 million pounds). This resource estimate assumes that Impact has diluted its interest in the Yarrabubba Project to 20 %.
A detailed airborne radiometric survey was fl own by the YB Nickel Joint Venture over the tenement area during 2005. This has shown that there are more than 70 kilometres of drainage channels that are prospective for calcrete-hosted uranium on the tenements and that there may be further such channels concealed beneath recent alluvium.
(Figure: Ternary Image of the Radiometric Data over the Yarrabubba Project (RGB=KThU)
Proposed Exploration
There is potential for further deposits of uranium oxide to be discovered, as well as extensions to the known deposit at
Nowthanna. Further work will be directed at establishing the size and grade of this deposit as a matter of priority, by way of a full re-evaluation of the results of the existing drilling together with further infill and step-out drilling.