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| Lake Torrens Project: Iron-oxide Copper-Gold-Uranium (IOCGU deposits), 100% Tasman
Tasman has a very large and strategic tenement holding (over 2,000 km2) adjoining BHP Billiton's world class Olympic Dam deposit in central South Australia (Figure 1). The prime target is iron-oxide associated copper-gold-uranium deposits of the Olympic Dam style, although potential for other base metal and diamonds deposits has been recognised.
Tasman has been exploring these tenements for a number of years, with drilling having been conducted at a number of prospects, including Titan, which contains sub-economic IOCGU-style mineralisation.
Vulcan Prospect
In late-2009 Tasman drilled the first hole at the Vulcan prospect, located about 30km north of Olympic Dam (Figure 1). The hole was drilled on the north western margin of a large gravity anomaly (about 5 km across), which compares very favourably in size with other IOCGU deposits such as Olympic Dam or Carrapateena (see Figure 2). The prospect also exhibits interesting magnetic and seismic anomalies, and is located very favourably with several of the key tectonic lineaments which were part of the original targeting tools used in the discovery of Olympic Dam (Figure 1).
All of the eight drill holes so far completed at Vulcan (refer Figure 3) have intersected alteration and mineralisation associated with the Vulcan IOCGU system. The best results have been from holes VUD 003, VUD 007 and VUD008, which intersected much stronger IOCGU mineralisation than the discovery hole VUD 001 drilled in November 2009.
Hole VUD 7 intersected strong chlorite/sericite altered basement volcanics at 847m followed by a thick zone of "classic" IOCGU-style mineralised hematite breccias between 1065m and the bottom of the hole at 1227.8m, (see drill core photo Figure 4). This interval of 162m averaged 0.25% Cu, 0.07g/t Au, 2.4g/t Ag and 0.04kg/t U3O8. Mineralisation consists of disseminated pyrite (iron sulphide) and chalcopyrite (copper iron sulphide), hosted within a breccia composed of fine grained black to steely-grey hematite, with lesser carbonate minerals and quartz.
The most recent hole, VUD 8 intersected 180m of alteration and some mineralisation including the copper sulphide mineral, bornite in one part of the hole (Figure 5). The presence of bornite and higher copper sulphur ratios is considered particularly encouraging. It indicates, by analogy with the key sulphide zoning patterns and grade distributions seen at Olympic Dam, that there is potential to find the upper parts of the sulphide zoning sequence, and hence higher grade mineralisation elsewhere within the Vulcan system. This hole included 21m of 0.63% Cu, 0.28g/t Au and 0.17 kg/t U3O8 from 910m within a thicker lower grade copper zone.
Hole VUD 3 drilled in 2010 included 7.8m down hole at 1.21% Cu, (and 0.35g/t Au). This 7.8m zone is included within a much thicker interval of 56.65m at 0.59% Cu, which also included a number of other higher grade zones such as 0.75m at 4.44% Cu, 1.34g/t Au, 0.58kg/t U3O8 and 0.65m at 7.82% Cu, 2.41g/t Au and 0.03kg/t U3O8.
Hole VUD 2 also intersected anomalous rare earth element concentrations, with one five metre zone (from 947m to 952m down hole) averaging 0.29% Ce and 0.18% La, comparable to levels seen in mineralised hematite-rich breccias at Olympic Dam. VUD 004 intersected a 1.37m thick zone at the basement unconformity averaging 0.91kg/t U3O8.
The main sulphide minerals intersected in the holes drilled so far are pyrite and chalcopyrite and not the higher tenor bornite or chalcocite as seen in higher grade parts of the Olympic Dam Deposit. However, Vulcan is clearly large enough (about 11km2) for significant development elsewhere within the system of this style of higher-grade, and economically more attractive mineral assemblage. Further, individual sections of these holes have returned assays for copper, uranium, gold, cerium and lanthanum that are equivalent to the higher-grade ore mined at Olympic Dam, confirming that the system has the potential to produce high-grade mineralisation.
The results from recently completed hole VUD 7 are considered a major exploration breakthrough for the following reasons:
They confirm that Vulcan hosts mineralisation of the same style, and of comparable thickness to that which makes up a very large portion of the nearby Olympic Dam IOCGU deposit, particularly the large tonnage bodies that occupy the south-eastern part of Olympic Dam. VUD 7 is located in the previously undrilled far eastern "limb" of the Vulcan prospect, a significant distance from the other parts of the prospect as defined by the geophysical anomaly and the earlier drill holes. It seems likely that mineralisation may extend considerably further east north-east from VUD 7 (Figure 1). VUD 7 considerably enhances the potential of the much larger, and believed to be more prospective (and as yet untested) southern portion of the prospect which is interpreted to be at a slightly shallower depth.
Recent PACE funded Re-Os age dating of the mineralisation at Vulcan gave an average age of 1590 Ma which is essentially the same geological age as other significant IOCGU deposits such as Olympic Dam, Prominent Hill and Carapateena. Although this result is not unexpected, it confirms that Vulcan is indeed a member of a very significant family of ore deposits, and with further investigation could prove to be a major deposit itself.
To view Figures 1 to 5 click on the link below (to download 429kb pdf file).
Figures 1 to 5
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| Lucas Hill Project: Iron-oxide Copper-Gold-Uranium (IOCGU deposit), 100% Tasman
Tasman has recently identified a new IOCGU (or Iron-Oxide Copper Gold Uranium) target at Lucas Hill, approximately 25km south east of Woomera and 100km south of Olympic Dam on the Stuart Shelf in South Australia (Figure 6).The target area was identified on the basis of the following parameters:A discrete, probably basement-sourced gravity anomaly (Figure 7), apparently larger in size and of comparable strength to the Carapateena deposit, 48km to the east northeast. An associated magnetic anomaly of comparable area. A prime regional location - within the highest priority, IOCGU Potential Zone 1 as defined by Geoscience Australia. Coincident and aligned along a major west northwest tectonic lineament (Figure 1) as originally defined during WMC's exploration that led to the discovery of Olympic Dam in 1975.
The untested basement gravity anomaly and associated magnetic anomaly were investigated by a previous explorer. It was believed that the source of the anomalies was likely to be about 900m depth, but the anomaly was not drilled.Geophysical modeling just completed indicates that the likely source of the gravity and magnetic anomalies at Lucas Hill is a significant body of quite dense material, becoming more magnetic at depth. The modeled depth to this body is about 1000m.Tasman believes, despite its depth, this target's geophysical characteristics and favourable infrastructure clearly confirm it as a high priority target.Tasman proposes to drill test the anomaly in January 2012.
To view Figures 6 & 7 click on the link below (to download 313kb pdf file).
Figures 6 & 7 |
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| Parkinson Dam Epithermal Gold-Silver (Lead-Zinc) Project, 100% Tasman
Tasman discovered this new epithermal-style system in mid-2005, following regional targeting of the area and the follow-up of anomalous geochemistry from previous explorers. The project is located about 60km west of Port Augusta in South Australia, and is strategically well located close to major highways and infrastructure and regional centres.Mineralisation is mostly hosted by the Mesoproterozoic-age Corunna Conglomerate and is characterised by quartz veining with sericite, chlorite and sulphide alteration halos, and occurs over about 4.5kmē. Tasman's initial drilling returned intersections up to 3.4g/t Au and 45g/t Ag over 3m, with thick zones of low grade lead and zinc (eg 96m at 0.2% Pb and 27m at 0.4% Zn). The first follow up diamond drill hole returned a 1.66m intersection of 7.6% Pb, 10.5% Zn, 0.4% Cu, 1.2g/t Au and 120g/t Ag.
In 2007 an intersection of 21m at 21g/t Au and 83g/t Ag (including 9m at 31g/t Au and 152g/t Ag) was obtained in a vertical diamond drill hole. This encouraging result has been followed up with further drill holes, but unfortunately this high grade mineralisation appears to be fairly limited in extent.Further drilling, designed to follow up encouraging thick zones of associated lead-zinc mineralisation hit in previous drilling is being considered. At least one deep hole may be drilled down dip of holes PD 70 (50m @0.9% Zn, 0.4% Pb) and PD 71 (55m @0.6% Pb and 0.4% Zn).
Tasman has also identified uranium potential within the project area, and this is being evaluated by uranium-focussed explorer Mega Hindmarsh, under joint venture with Fission Energy Ltd. Fission have a uranium only joint venture agreement with Tasman.
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| Central Gawler Gold Project, 100% Tasman
Central Gawler, which includes the Skye, Birdie and Gof North prospects, is located about 95km southwest of Coober Pedy. Archaean structurally controlled gold targets (including the Challenger-type) have been identified based on regional calcrete sampling and geophysical interpretation. These prospects were originally drilled by previous explorers. Tasman′s objectives are to both explore around mineralisation identified earlier, but poorly tested, and to test new anomalies and zones defined by follow up exploration. Drilling by Tasman at the Skye prospect has located a 15m wide low grade mineralised zone at depth including 6m @ 2.9g/t with potential for narrow high grade plunging shoots.
Southern Gold have reported encouraging results from drilling at the Golf Bore prospect, located several hundred metres southwest of Tasman's Golf North prospect, which was discovered by an earlier explorer.
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| Garford Project, Columba Oil Shale Prospect, 100% Tasman
The Garford project is located 80km southwest of Coober Pedy and 30km west of the Port Augusta to Darwin railway. Drilling by Tasman to test an interpreted Mesozoic-Permian trough for coal, encountered 7m to 30m thicknesses of strongly carbonaceous black organic rich Tertiary mudstones at various points along its 40km length at shallow depths of around 7m to 15m metres. One 2m composite sample of carbonaceous material from one hole was tested to determine its oil shale potential. After a series of preliminary tests on the sample, a pyrolysis gas chromatography analysis was conducted and indicated extremely good potential for oil generation. Follow up work is required to determine the oil shale potential.
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| SA Diamond Project, Diamond JV with Flinders Mining Ltd
Diamonds and indicator minerals are known in several areas of South Australia. The central Gawler Craton has an area with thick cool Mesozoic crust considered prospective for diamondiferous kimberlites.
Tasman has partnered with Flinders Mining Ltd to assess Tasman's Central Gawler and Lake Torrens licences for diamond deposits. Flinders are undertaking an integrated programme of detailed airborne magnetics over targets selected from regional data; target ranking based on Flinders experience with locating kimberlites; ground magnetic follow-up of selected targets and drilling testing of priority targets.
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| OTHER INTERESTS
Alternative Energy
Through its holding in Eden Energy Ltd, Tasman has interests in various alternative energy technologies involving hydrogen, coal seam and abandoned mine methane and geothermal energy.
Cobalt - Nickel and Uranium
Through its holding in Fission Energy Ltd, Tasman has an interest in the Mt Thirsty Co-Ni-Mn oxide deposit located near Norseman in Western Australia. Indicated and Inferred resources are currently 29 million tonnes grading 0.56% Ni, 0.12% Co and 0.88% Mn. The Mt Thirsty Joint Venture is working closely with consultancy firms to define the best development options for the project. A pre feasibility study is planned to commence in August 2010.
Fission also has a number of uranium exploration projects on The Gawler Craton in South Australia and one uranium prospective application in Western Australia.
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