West Australian gold explorer Focus Minerals (ASX: FML) has announced the update of the Bonnie Vale Quarry Lode resource to support the upcoming pre-feasibility study at the company’s Coolgardie project in the goldfields of WA.
Bonnie Vale Quarry Lode resource model updated to reflect understanding of geology.
6.4 % total resource growth achieved from updated model and reduction of cut off grade to 1.5 g/t Au.
Bonnie Vale update to be included in the upcoming 2020 Coolgardie PFS update.
The Bonnie Value Quarry Lode is an underground resource and reported on a dry tonnage basis. The cut off grade for Bonnie Vale has been shifted from 2.0 g/t to 1.5 g/t in alignment with the soon to be reported PFS that assumes a gold price of A$2,200/oz. The updated resource comprises:
Bonnie Vale is a core part of Coolgardie, which covers 175km2 of highly prospective tenements on the outskirts of the Coolgardie township in the Goldfields. The Bonnie Vale Quarry Lode provides highgrade and high-value mineralisation with excellent recovery characteristics. Focus is finalising an update to the 2017 Coolgardie PFS, which will incorporate the updated Bonnie Vale mineral resource in the study. The PFS is due for completion in September 2020.
Bonnie Vale Quarry Lode
Future underground resources for Coolgardie mining re-start
Bonnie Vale is located 9km north of the township of Coolgardie in the Eastern Goldfields. It is situated on Mining Licences M15/595, M15/877 and Prospecting Licence P15/5159, which are wholly owned by Focus. The quarry lode is 9km north north-west of Focus’ Three Mile Hill processing plant (on care and maintenance).
The Bonnie Vale area was a major underground gold producer from 1894 to 1911 with recorded production figures of 176,883oz at an average grade of 16.2g/t. The deepest workings extend to a depth of 270m below surface.
Focus last updated Bonnie Vale’s mineral resource in 2018 (see ASX announcement dated 30 May 2018) and completed one RCDD hole in March 2019 for 546.7m. The hole intersected shearing with veining from 490-494m. However, proposed geotechnical review of the core was delayed by the Coolgardie sale process in 2019. As such the core remains un sampled at this point.
On the back of Focus’ announcement on 9 July 2020 to update the 2017 Coolgardie PFS, the Company has reviewed the Bonnie Vale Quarry Lode resource with the following modifications:
Rotated model to better reflect the narrow mineralisation as recommended in the 2017 PFS. This update had a minor effect on the overall calculated resource but, is considered better for the purpose of calculating dilution and reserves for narrow high grade mineralised systems;
Review of geological model to improve classification of ore and waste especially with respect to PFS planned mine development/stoping;
Review of density data to better reflect geological domains;
Paired-back inferred mineralisation where it was likely truncated by geology; and
Reduced cut off grade from 2.0 to 1.5 g/t in alignment with PFS assumption of AUD $ gold price of 2,200/oz.
All up the changes deliver a 6.4% increase to total indicated and inferred Bonnie Vale Quarry Lode Resource.