The Karlawinda gold project is in Western Australia, located 65 km southeast of the town of Newman. The project area is close to key infrastructure and mining support services. In April 2017, total Resources (JORC 2012) for the project were estimated at:
31 million tonnes @ 1.1g/t Au for 1,114,000 ounces of gold
Gold mineralisation at the Francopan Prospect was originally discovered by WMC Resources Ltd in 2005. The project was subsequently acquired by Independence Group (IGO) in 2008 resulting in the discovery of the significant Bibra Gold Deposit in 2009.
At the time of acquisition of Karlawinda from IGO by Capricorn, approximately A$12 million had been spent on regional exploration, resource evaluation and prefeasibility activities.
Subsequent work by Capricorn in 2016 included over 80,000m of RC and Diamond drilling at the Bibra Deposit and the completion of a Scoping Study in July 2016.
Importantly, a Native Title Access Agreement was signed in November 2016, followed immediately by the grant of Mining Lease M52/1070.
In August 2017, a maiden Reserve (JORC 2012) was estimated for the Bibra Deposit comprising:
21 million tonnes @ 1.06g/t Au for 713,000 ounces of gold
The Ore Reserve is contained within a detailed, staged open pit design with a stage one stripping ratio of 2.9:1 and a life of mine (LOM) stripping ratio of 4.7:1. The stage one pit shells contain predominantly laterite and oxide mineralisation.
A Feasibility Study on development of the Bibra deposit is due for completion in the September Quarter 2017. The study is based on a single large open pit deposit feeding a 3Mtpa CIL processing plant, producing approximately 100,000ozpa over an initial mine life of approximately seven years.
The Bibra deposit is hosted within a thick, shallow-dipping gold mineralised structure which is amenable to low-cost open pit mining with mineralisation starting close to the surface. The deposit remains open in down-plunge positions and potential exists for strike extensions and stacked mineralised lodes
Bibra is part of a large-scale Archaean-aged gold mineralized system. The deposit is hosted within a package of deformed volcanic and meta-sedimentary rocks, mineralisation has developed on at least two parallel, shallow dipping structures; supergene laterite and oxide mineralization has developed over the structures close to surface.
The deposit is oxidized to average depths of 50-70m. Significantly, a gold-enriched, horizontal laterite zone lies within 15m of surface, containing 1.54 million tonnes @ 1.4 g/t Au for 67,600oz (within the abovementioned 1,114,000 oz resource). The shallow dipping (25-30 degrees from horizontal) nature of mineralisation is amenable to efficient open-pit mining and relatively low waste: ore stripping ratios.
Bibra Resources and Reserves
In April 2017, an update of the previous (July 2016) JORC 2012 Resource estimate for Bibra was undertaken. Subsequently in August 2017 a maiden Ore Reserve estimation was undertaken.
Notes on the April 2017 Mineral Resource Estimate:
1. Refer to ASX anouncement of 10/04/2017 full details.
2. Discrepancy in summation may occur due to rounding.
3. The mineralisation has been wireframe modelled using a 0.3g/t Au assay cut-off grade. The resource estimate has been reported above a block grade of 0.5g/t Au.
4. The resource has been constrained by a A$1750/ounce conceptual optimal pit shell.
5. Ordinary kriging was used for grade estimation utilising Surpac software v6.6.2.
6. Grade estimation was constrained to blocks within each of the mineralised wireframes.
7. See ASX announcement dated 4th July 2016 for Inferred Resource announcement.
Notes on the August 2017 Ore Reserve Estimate:
1. Refer to ASX anouncement of 7/08/2017 full details
2. Reserves are a subset of Resources
3. Ore Reserves conform with and use the JORC 2012 Code definitions
4. Ore Reserves are calculated using a gold price of A$1500/ounce
5. Ore Reserves are calculated using a cut-off grade between 0.40g/t and 0.47g/t Au
6. Mining dilution, estimated by modelling to a Selective Mining Unit (SMU) with dimensions of 5m x6.25m x2.5m result in a reduction of 13% of reportable Au ounces
7. All figures are rounded to reflect appropriate levels of confidence which may result in apparent errors of summation
Regional Exploration Potential
The Karlawinda Project remains largely unexplored. Since the discovery of the Bibra Deposit the focus has largely been on detailed assessment of that resource. Outside of Bibra and the original Francopan discovery (81m @ 1.2 g/t Au) regional exploration remains at an early stage and is limited to wide spaced aircore drilling, surface geochemistry and programs of geophysics.