Peak Hill
The host lithologies for the gold mineralisation comprise the very prospective Narracoota Formation and the Peak Hill Schist. Mineralisation extends from surface to 300 m below surface and is open along strike and at depth in most areas. The Harmony, Main/5Ways, Mt Pleasant and Jubilee pits were mined during historically lower gold prices, leaving large unmined resources behind. Other areas such as Durack and Enigma were not mined for the same reasons.
Mineral Resource estimates have been calculated in accordance with the JORC Code 2004 for the Harmony, Mainpit/Fiveways, Durack and Enigma gold deposits within the Peak Hill Project. The Mineral Resource estimates were completed on behalf of the Company by Snowden Mining Industry Consultants (“Snowden”), and combined with the Mineral Resource estimate for the Jubilee deposit completed previously by CSA Global Pty Ltd (“CSA”), enable a global Mineral Resource estimate to be presented for the Peak Hill Project.
In preparing the estimates for the Harmony, Enigma, Durack and Mainpit/Fiveways deposits, Snowden considered material within 150 m of the surface to be suitable for open pit mining and chose a reporting cut-off of 0.8 g/t Au based on similar deposits. Material below 150 m will potentially be mined from underground and has been reported at a cut-off of 2.0 g/t Au based on similar deposits. Density values of between 1.9 and 2.6 g/cm3 were applied dependant on the degree of weathering.
In 2009 CSA Global Pty Ltd. (“CSA”) was commissioned by the Company to undertake Mineral Resource estimates for the J2 and J3 zones at the Jubilee gold project, located 2 km north of the historic Peak Hill Mine site. In preparing the estimates CSA used a 1 g/t Au cut off.
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Table 1. June 2011 Mineral Resources completed by Snowden |
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Classification |
Material |
Tonnes |
Au |
Ounces |
| Oxide | 1,270,000 | 1.24 | 50,000 | |
| INDICATED | Transitional | 2,940,000 | 1.35 | 128,000 |
| Fresh | 4,960,000 | 1.58 | 252,000 | |
| TOTAL INDICATED | 9,170,000 | 1.46 | 430,000 | |
| Oxide | 160,000 | 1.00 | 5,000 | |
| INFERRED | Transitional | 80,000 | 1.12 | 3,000 |
| Fresh | 1,510,000 | 1.57 | 76,000 | |
| TOTAL INFERRED | 1,750,000 | 1.50 | 84,000 | |
| SUBTOTAL | 10,920,000 | 1.47 | 514,000 | |
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Table 2. September 2009 Mineral Resources completed for the Jubilee Deposit by CSA. |
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Classification |
Tonnes (t) |
Au (g/T) |
Ounces (oz) |
| INDICATED | 100,000 | 1.95 | 6,300 |
| INFERRED | 505,000 | 2.49 | 40,500 |
| SUBTOTAL | 605,000 | 2.41 | 46,800 |
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TABLE 3. Combined Global Mineral Resources Estimated for the Peak Hill Project |
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Classification |
Tonnes |
Au |
Ounces (Oz) |
| INDICATED | 9,270,000 | 1.46 | 436,000 |
| INFERRED | 2,255,000 | 1.72 | 125,000 |
| TOTAL | 11,525,000 | 1.51 | 561,216 |
Regional Geology of the Peak Hill gold field showing known deposit locations
Numerous historic RAB and RC holes indicate that a lot of potential remains both near these historic pits and along strike extensions.