Wiluna Mining Corporation Limited (ASX: WMX) has drilled further wide, high-grade intersections close to existing mine workings from an additional 30 holes and 8,218m of drilling at the Wiluna Mining Centre (WMC) in Western Australia.
The company’s major drilling programme is focused on defining additional reserves in the highest-value zones scheduled for mining in the next five years to further enhance the mine plan.
The company is also undertaking structural interpretation to predict the location of further high-grade discoveries and processing the results of a seismic survey recently undertaken to identify new exploration targets, with results to be communicated in due course.
Drilling at the Starlight, Essex, Calvert, East Lode South and Golden Age areas continues to define high-grade intervals at shallow levels, close to multiple previously mined zones with existing access which allows rapid low-cost of development per mined ounce.
Executive Chair, Milan Jerkovic, said these results confirm the company’s strong view that the Wiluna Operation will develop into a larger-scale, high-grade, and long-life gold mine.
Drilling at Golden Age continues to deliver very high grade free-milling quartz reef intercepts in resource extensional drillholes, and these results are expected to materially enhance grade and production during the transition to, and in parallel with, the addition of sulphide production in the two-staged development at the Wiluna Mining Centre.
Essex is a high-grade, high-priority mining zone in the Wiluna Central Mine area, which continues to deliver visible gold intersections in numerous holes down-plunge of the current resource limits. The success of the Company’s drilling and resource development activity at Essex, validates the company’s strategy to focus on shallow, high-grade sulphide ore bodies for development early in the mine plan. Access to the Essex orebody installed by previous operators is currently being dewatered and rehabilitated to facilitate infill drilling around the deeper visible gold intersections with the view to delineating additional resources and reserves.
While new high-grade zones have been discovered at Essex and Starlight. At Essex Holes WURD0116A and WURD0124 intersected bonanza grades with visible gold mineralisation over narrow intervals, reflected in the ultrahigh-grade assays of 2.35m @ 61.05g/t from 293.95m including 0.37m @ 313g/t, and 2.00m @ 43.23g/t from 437.00m including 0.52m @ 159g/t, respectively.
This result follows up previously released intersections shown on Figures 2 and 3 of 2.45m @ 31.30g/t and 1.75m @ 19.55g/t.
Further drilling is planned to close-off and complete the infill of this high-grade lode discovery with a view to defining an ore reserve to enhance the front end of the underground mine plan at the Wiluna Mining Centre.
The Starlight zone in the Wiluna North Mine area continues to take shape, with further high-grade sulphide intersections located at shallow depths and open down-plunge. Starlight is significant in that it is located only 200m away from the existing underground mine development activity and could be rapidly brought into production at low capital cost if further drilling demonstrates economic reserves.
Multiple subparallel wide sulphide zones in the central portion of the deposit remain open down-plunge (5.00m @ 5.74g/t, 6.00m @ 6.64g/t, 4.00m @ 6.59g/t) and further assays are awaited. In addition to WUDD0069, numerous additional significant results are assisting in understanding the geological controls on mineralisation to guide planned follow-up drilling.
Following the 93,000m of resource and reserve development drilling completed in 2020, the Wiluna Mining Centre Mineral Resource Estimate has increased to 60.2Mt @ 2.99g/t for 5.78Moz (above 1.0g/t cut-off), including a high-grade component of 26.9Mt @ 4.89g/t for 4.24Moz above 2.5g/t cut-off. Approximately 50% of the Mineral Resource is in the Measured and Indicated categories and 50% in the Inferred category.
In March 2021, the company published updated underground Ore Reserve at Wiluna of 4.33Mt @ 4.74g/t for 661koz, an increase of 142% on the previous estimate.
The 2021 drilling programme is of similar scale, with six to eight rigs operating for the next six months, with the aim to grow reserves at new high-grade shoot discoveries “under-the headframe” and progressive infill drilling to convert the current Inferred Resource of 2.10Moz @ 4.57g/t (above 2.5g/t cut-off) to Indicated category.
Including historical production of over 4Moz, Wiluna’s total endowment is over 10Moz which ranks Wiluna alongside an exclusive peer group of large-scale, long-life mining centres in the Western Australian gold fields. Most historical production and existing resources occur in the upper 600m at Wiluna, with limited drilling during the past 15 years at depth on Wiluna Mining’s exploration targets, which Wiluna Mining will systematically drill out to complete the resource and reserve development programme over the next three to five years.