Horseshoe Lights Project (100%)
Location
The historic Horseshoe Lights gold-copper mine and associated tenements are located approximately 800km north-northeast of Perth and 140km north of Meekatharra (Figure 1).
The Horseshoe Lights Project comprises sixteen tenements that cover an area of approximately 79.98km2 (see Figure 3).
Production History
The Horseshoe Lights deposit was discovered in 1946 and was in production up until 1994.
The total life of mine production to 1994 is summarised in the table below:
Period | Owner | Type | Tonnes | Au (g/t) | Cu (%) | Ag (g/t) | Hg (g/t) |
1946-87 | Various | Gold ore | 1,519,446 | 4.2 |
|
|
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1988 | Barrack | Gold ore | 90,360 | 4.6 |
|
|
|
1988-91 | Barrack | Total treated | 934,703 | 1.9 | 2.7 | 44.0 | 26.3 |
1992-94 | Sabminco | Total treated | 754,611 | 1.6 | 3.9 | 66.0 | 37.3 |
Total |
|
| 3,299,120 | 2.9 | 1.7 | 27.5 | 16.0 |
In-Situ Mineral Resources
In October 2011, the Company commissioned CSA Global Pty Limited to undertake a JORC compliant mineral resource estimation using the historical drilling database and the results from the company's 2010/11 drilling programmes (41 RC drill holes for 8,362m).
The mineral resource estimation identified an Measured, Indicated and Inferred Mineral Resource of 8.4Mt at 1.1% Cu and 0.14g/t Au at a cut-off grade of 0.5% Cu containing 91,400 tonnes of copper and 36,400 oz of gold.
Stockpiles
A summary of low-grade copper-bearing material remaining on surface at Horseshoe Lights in stockpiles, dumps and tailings is given below.
Low-grade Stocks Estimate | ||
Stockpile | Tonnes | Copper % |
Flotation Tailings | 1,420,000 | 0.47 |
M15 | 244,000 | 0.98 |
Sub grade | 38,000 | 0.80 |
Barrack dump | 250,000 | 0.80 |
Total | 1,952,000 | 0.58 |
Exploration Potential
The potential to host additional copper-gold resources within the current tenements can be supported by the following evidence:
- Past production of around 3.3Mt at 1.7% Cu and 2.9 g/t Au demonstrates the project area is significantly mineralised.
- The area has major regional shear structures that have tended to displace the mineralised zones that were being mined (such as the east northeast striking fault recognised late during the mining that terminated the main ore-body. These structures have excellent potential to yield en-echelon ore-body repetitions elsewhere within the project area.
- There has been extensive surface disturbance, potentially obscuring any surface expression of mineralised extensions and hampering access for drilling; and as a result there has been little exploration to locate potentially displaced mineralisation.
- The use of geophysics was limited by the then existing mine infrastructure
- Opportunity exists to increase the zone of mineralisation either along strike or down dip of the known ore-body due to the gaps that exist in the previous drilling. These untested zones represent the highest priority for future drilling programs.
- Potential also exists for en-echelon repetitions of the Horseshoe Lights deposit, especially in the area immediately east of the pit, near the CIP tailings dam and vat leach areas. These areas have only received limited drilling in the past.
