Current Mineral Resources – SRK Consulting August 2005
SRK Consulting was commissioned to provide an independent technical assessment of the mineral assets and exploration tenements at Redbank. The following table is an extract from the report that is contained in the prospectus issued by the Company on 3 November 2005.All stated resources are open at depth and amenable to both open and bulk underground mining. Punchbowl is also open laterally.
| Resource | Tonnes | % Cu | Tonnes Cu | lb's Cu |
|---|---|---|---|---|
| Measured | ||||
| Transitional Ore (stockpiles) | 18,000 | 6.5% | 1,170 | 2,579,000 |
| Oxide Ore (stockpiles) | 36,000 | 5.8% | 2,090 | 4,610,000 |
| Total Measured | 54,000 | 6.0% | 3,260 | 7,187,000 |
| Indicated | ||||
| Sandy Flat (i) | 467,000 | 1.6% | 7,550 | 16,704,000 |
| Bluff (ii) | 528,000 | 1.9% | 10,250 | 22,580,000 |
| Total Indicated | 995,000 | 1.9% | 17,800 | 39,284,000 |
| Inferred | ||||
| Sandy Flat (i) | 1,523,600 | 1.2% | 17,500 | 38,630,000 |
| Bluff (ii) | 1,036,000 | 1.4% | 13,959 | 30,830,000 |
| Punchbowl (iii) | 620,000 | 2.0% | 12,400 | 27,280,000 |
| Total Inferred | 3,179,600 | 1.4% | 43,850 | 96,740,000 |
| Total Mineral Resource | 4,229,000 | 1.5% | 64,910 | 143,211,000 |
- Database of 70 drill holes to a depth of 405m. Wireframe used to create domain for resource estimate using LeapfrogTM software with a 15m maximum extension at a cut-off of 0.5% Cu above 700m RL (approx 90m below the natural surface), 40m above the base of the current open pit; unconstrained LeapfrogTM modelling used below 700m RL, with a 3.5% Cu cut–off for a separate high grade zone in the supergene. Density applied 2.1 t/m3, derived from previous testwork and 10 core samples selected from fresh core in April 2005. Blocks above the 700mRL classified as Indicated; blocks below the 700m RL classified as Inferred due to lack of downhole surveys.
- Database of 35 drill holes to a depth of 335m. LeapfrogTM software used to create a wireframe interpretation at a 0.4% Cu cut-off. Due to two mineralisation controls being evident, a steeply plunging breccia pipe and shallowly dipping mineralisation in the surrounding sedimentary rocks, wireframing was done in two passes. A review of assay data revealed an especially high grade zone within the low grade zone, modelled using a 2.5% cut-off. Grades were estimated in low grade zone using Ordinary Kriging with x and y block sizes of 15m each, z block size of 3m, search distance of 100m, octant search type, minimum and maximum composites of 8 and 32 respectively. Density applied 2.1 t/m3.
- Database of 20 percussion holes to a depth of 40m plus several diamond holes reported (diamond holes not used for resource estimation). LeapfrogTM software used to create a wireframe interpretation at a 0.5% Cu cut-off. Density applied 2.1 t/m3. 62 composites of 3.08m (10’) used with a top cut of 6% Cu average grade applied to the resource.
Significant Intersections outside estimated resources
The following highlights reported diamond, percussion and Reverse Circulation (RC) drilling results from the Punchbowl, Bluff East, Target Zone 16, Redbank, Roman Nose, and Azurite prospects (source: SRK Consulting Report). End of intersections marked "*" are open downhole:
| Hole | From | To | Interval | Cu % |
|---|---|---|---|---|
| Target Zone 16 (percussion) | ||||
| A042 | 3.0 | 21.3* | 18.3 | 6.5 |
| A046 | 6.1 | 25.6* | 19.4 | 8.8 |
| A0116 | surface | 15.2* | 15.2 | 1.5 |
| Redbank (reverse circulation) | ||||
| AZDH40 | 9.1 | 30.5* | 21.4 | 3.4 |
| AZDH44 | surface | 30.5* | 30.5 | 1.9 |
| Roman Nose (diamond) | ||||
| RN1 | surface | 167.7* | 167 | 0.5 |
| Azurite (reverse circulation) | ||||
| AZI | 3.0 | 21.3* | 18.3 | 1.6 |
| RDH008 | surface | 30.5* | 30.5 | 1.0 |
| RDH012 | surface | 30.5* | 30.5 | 1.3 |
| Punchbowl (Diamond drill intercepts below SRK's resource estimate area) |
||||
| AD1 | 38.0 | 158.0 | 120. | 1.0 |
| AD1 | 200.0 | 292.0 | 92.0 | 0.9 |
| Bluff East (Percussion) | ||||
| A064 | surface | 36.6* | 36.6 | 2.1 |
| A077 | surface | 30.5* | 30.5 | 1.5 |