Coronation Hill Gold Occurrence, NT

Abstract

A review report which examines evidence from previous work by United Uranium NL and Noranda Australia Limited (on behalf of the South Alligator Joint Venture) for gold mineralisation at Coronation Hill and surrounding prospects. The report makes specific recommendations for an exploration programme to follow up on this evidence. The main part of the recommended drilling programme would test an area of 250m by 120m to a depth of 100m, extending from existing workings, as well as to an SP anomaly at Coronation Hill South east, a radiometric anomaly at Coronation Hill South west, and a copper occurrence at Callanan's Prospect. UUNL completed 6 DDH which defined a zone 60m by 12m which contained an average 0.49% Cu and 0.005% U3O8. Further exploration of areas not associated with uranium or base metal mineralisation, particularly around El Sherana and Palette, is also recommended. In these areas consideration should be given to testing known mineralised structures such as shear zones in Koolpin Formation, where these are obscured by cover rocks along strike from the workings. Where this cover is less than about 50m, angled diamond drill testing of the Koolpin should be considered.

The report notes that an earlier reappraisal of UUNL drilling by Foy and Wyntje in 1974 also provided estimates of substantial 'indicated' and 'potential' mineralisation. The original UUNL wagon drilling was directed at identifying a gold resource, but assays were sporadic and only done on cutttings from which visible gold was panned. The report concludes that because of data deficiencies, previous and current estimates should be regarded as indicative of the potential of the area.

Crohn reviews five substantially different interpretations of the geological setting of the mineralisation without making firm conclusions, which he predicts will emerge from further drilling.

The unreliability of AAS assaying for Au, at least in the 1970s, is highlighted, as is the erratic distribution of gold in drill samples, implying the presence of coarse gold particles.

Production of ore amounted to 26,000 tons averaging 5.9lbs/t U3O8, mined by open cut and lory hole connected to an adit at 900foot level.