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Prospect Hill Tin Project SummarySignificant tin mineralization has been discovered at Prospect Hill. Given the exploration potential and favourable metallurgy, the project has good prospects for developing into South Australia's first modern tin mine. HistoryThe Prospect Hill tin project, located in the northern Flinders Ranges, is South Australia's largest known tin resource and remained unexplored for almost two decades until re-kindling of interest by the current high tin prices. Previous shallow drilling by Marathon Petroleum in the early 1980's established an inferred resource of 172,000 tonnes of 1.15% tin to a vertical depth of 50 metres and over a strike length of 280 metres on the South Ridge prospect, based in part on some high grade tin intersections, including:
The South Ridge tin mineralization is associated with anomalous copper, zinc, lead, uranium and silver identified along a strike length of more than 1,200 metres. Havilah entered into a joint venture in September 2007, whereby it may earn up to an 85% interest in the tenement by completing a feasibility study. Thereafter, the vendors may contribute their 15% share of development costs or revert to a net smelter royalty. Havilah ExplorationIn October 2007 Havilah completed a 19 hole, 1195 metre drilling programme with the objective of expanding the published resource and also testing the North Ridge prospect. Economic grades of tin mineralization were confirmed in several holes on the South Ridge prospect, at comparatively shallow depths, including:
The higher grade tin mineralization often occurs within broader lower grade tin halos and may be associated with potentially economic grades of copper, lead, zinc and silver. In PRC05, for example, the main tin mineralized interval from 13-16 metres also contains 1% copper, 2.2% lead, 1.76% zinc, 199 ppm uranium and 6.5 ounces silver per tonne. Preliminary metallurgical test work on three composite RC drill chip samples has confirmed that the tin, which is mostly present as free cassiterite grains, can be effectively recovered by gravity methods. For example, for the high grade composite (4.8% Sn) 84% of the tin reported to a 48% tin concentrate, while for the low grade composite (0.5% Sn) 79% of the tin was recovered into an 8.5% tin concentrate (along with abundant sulphide minerals and garnet). A second round of drilling completed in July 2008 comprised 24 holes for 2231 metres and was concentrated on the South Ridge Prospect in order to follow up the earlier high grade tin intersections. The aim was to expand the presently known tin mineralization beyond its current limits, with an initial open pit target objective of 700,000 tonnes of 0.8% tin. Drilling continued to confirm high grades, with intersections including
Together with several broad lower grade intercepts including
Of significance is the presence of significant mineralisation in the most easterly and westerly holes completed to date (holes PHRC29 and PHRC37) noted above. Drill data from all drilling and trenching completed on the South Ridge Prospect area has been utilised to obtain an indicated resource of 302,000 tonnes @ 0.64%Sn. Within this resource, a potential mineable resource of 164,000 tonnes @ 0.89% Sn has also been calculated. A broad Niton soil sample programme was completed to the west of the currently known resource and returned a peak Sn value of 3878ppm in an area with generally poor outcrop approximately 1.8 kilometres to the west of the current resource drilling. A significant rock assay of 3.7% Sn has also been rcorded from earlier exploration work approximately 350 metres west of the current resource. It is planned to follow up these anomalies with drilling in 2011, as well as investigating the alluvial tin potential. The eastern portion of the tenement also has considerable potential for the discovery of Tertiary palaeochannel hosted uranium deposits, in a geological setting that is very comparable with the Beverley – 4 Mile area that lies roughly 40 kilometres to the south. The key ingredients of suitable sand and gravel beds flanking basement outcrops that are highly elevated in uranium, are known to occur over a large area, and will also be targeted in a subsequent drilling programme.
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