ASX Announcement Westgold Resources Limited
18 November 2024
Bluebird - South Junction Mineral Resource Grows to 1.4Moz
65% increase in Measured and Indicated Resources to 8.7Mt @ 2.9g/t Au for 814koz
Perth, Western Australia, 18 November 2024: Westgold Resources Limited (ASX / TSX: WGX, OTCQX: WGXRF – Westgold or the Company) is pleased to announce a Mineral Resource Estimate update for the Bluebird - South Junction mining complex within Westgold’s Murchison business at Meekatharra.
Highlights
Bluebird – South Junction Mineral Resource Estimate (MRE) grows to 15Mt at 2.9g/t Au for 1.4Moz – a 37% increase.
- 65% increase in Measured and Indicated Resources - Measured and Indicated component now 8.7Mt at 2.9g/t Au 814koz.
- Mining study underway - with a view to updating the Bluebird – South Junction Ore Reserve during Q2, FY25.
Drilling program extended
- Two surface rigs and two underground drill rigs committed into 2025 - all parts of the mineralised system remain open at depth and to the south along strike.
- Drilling objectives are to extend and infill the system - providing data for optimisation of mine infrastructure positioning.
Polar Star access being accelerated
- Study underway considering second portal access - to allow for rapid drill-out of the Polar Star Lode within the Bluebird-South Junction mining complex.
- Second portal may convert to production decline - providing access to a third mining front, lifting mine outputs and deconstraining current Bluebird – South Junction mine plan from future mining at Polar Star.
Westgold Resources Limited westgold.com.au Level 6, 200 St Georges Terrace ABN 60 009 260 306 T: +61 8 9462 3400 Perth WA 6000 ASX: WGX | TSX: WGX | OTC: WGXRF E: [email protected] PO Box 7068, Cloisters Square WA 6850
Westgold Managing Director and CEO Wayne Bramwell commented:
“With 1.4Moz in resource and growing Bluebird-South Junction has now confirmed its status as the key growth driver in Westgold’s Murchison business.
In under 18 months, the team has moved a simple uphole bench mine producing at 40kt a month, towards a 110kt a month mine with a highly efficient transverse primary / secondary mining sequence. This transition is built upon continued investment in drilling delivering a 240% increase in the Mineral Resource base.
The significant upgrade in both total Mineral Resource and the Measured and Indicated component of the Mineral Resource Estimate has enabled mining studies to advance, and we anticipate an increase in the associated Ore Reserve over and above the currently reported 277koz.
This increase is expected to be delivered during H2, FY25.
In FY25 Westgold has unleashed the drills. In the Southern Goldfields preliminary works to support a seventh underground drill rig at Beta Hunt are underway, and the first resource development drilling program under Westgold ownership has commenced at the Lake Cowan project at Higginsville, with a view to providing a new source of feed to the Higginsville mill.
We look forward to providing ongoing updates on the outcomes of this investment throughout this year.”
Figure 1 - Bluebird – South Junction underground complex showing footprint of current Mineral Resource Estimate relative to previous Mineral Resource Estimate with recent significant drilling intersections displayed (refer Appendix B for detailed drill results).
Bluebird – South Junction - A Rapid Growth Story
The South Junction lodes at Bluebird (Figure 5) were identified as a priority growth opportunity following the results of initial drill testing in early 2023 (refer ASX 11 January 2023 - Bluebird Expansion and Drilling Update). A significant drilling program was initiated in January 2024 aimed at extending and infilling South Junction.
The timeline of the growth of Bluebird - South Junction since 2023 comprises:
• January 2023 – Identification of South Junction as a priority expansion target for the Meekatharra Gold Operations.
- First half of 2023 – preliminary mining assessment and drill planning phase.
- End of FY23 – Total MRE of 3.8Mt at 3.3g/t Au for 398koz Au (Table 1) resulting in a total (Bluebird) Ore Reserve of 757kt at 4.9g/t for 119koz (refer ASX 11 September 2023 - 2023 Resource and Reserves Statement).
- January 2024 – commencement of a substantial program of surface drilling works.
- April 2024 – Announcement of updated Bluebird – South Junction MRE of 6.4Mt at 3.1g/t Au for 827koz Au – a 107% increase over the previous MRE of FY23 MRE (refer ASX 16 April 2024 - Bluebird-South Junction Increases to 6.4Mt at 3.1 g/t Au).
- August 2024 – Announcement of Maiden South Junction Ore Reserve of 3.0Mt at 2.8g/t Au for 277koz Au – a 233% increase on the end of FY23 Ore Reserve. Commensurately an updated MRE of 11Mt at 2.8g/t Au for 960koz Au was announced (refer ASX 14 August 2024 Westgold Declares Maiden South Junction Ore Reserve).
• End of FY24 – Total MRE of 11.3Mt at 2.7g/t Au for 998koz (Table 2), 151% increase on the end of FY23 MRE (refer ASX 16 September 2024 - 2024 Mineral Resource Estimate and Ore Reserves).
- November 2024 updated MRE of 15.0Mt at 2.9g/t for 1.4Moz (Table 3), a 244% increase on the end of FY23 MRE (this announcement).
Table 1 – Bluebird - South Junction MRE as at the end of FY2023 (reported above 1.5g/t Au for underground portion and above 0.7g/t Au for the open pit portion – below and above a $2k/oz open pit optimisation shell respectively).
| Classification | Tonnes | Grade | Ounces | ||||
|---|---|---|---|---|---|---|---|
| (g/t Au) | |||||||
| Measured | 730,000 | 4.3 | 102,000 | ||||
| Indicated | 2,342,000 | 3.2 | 240,000 | ||||
| Inferred | 722,000 | 2.4 | 56,000 | ||||
| Total | 3,793,000 | 3.3 | 398,000 |
Table 2 – Bluebird - South Junction MRE as at the end of FY2024 (reported above 1.5g/t Au for underground portion and above 0.7g/t Au for the open pit portion – below and above a $2k/oz open pit optimisation shell respectively).
| Classification | Tonnes | Grade | Ounces | ||||
|---|---|---|---|---|---|---|---|
| (g/t Au) | |||||||
| Measured | 342,000 | 3.9 | 43,000 | ||||
| Indicated | 4,829,000 | 2.9 | 450,000 | ||||
| Inferred | 6,155,000 | 2.6 | 505,000 | ||||
| Total | 11,326,000 | 2.7 | 998,000 |
Table 3 – Current Bluebird - South Junction MRE as at the end of Q1, FY25 (reported above 1.5g/t Au for underground portion and above 0.7g/t Au for the open pit portion – below and above a $2k/oz open pit optimisation shell respectively).
| Classification | Tonnes | Grade | Ounces | ||||
|---|---|---|---|---|---|---|---|
| (g/t Au) | |||||||
| Measured | 321,000 | 4.0 | 41,000 | ||||
| Indicated | 8,410,000 | 2.9 | 773,000 | ||||
| Inferred | 6,238,000 | 2.8 | 556,000 | ||||
| Total | 14,969,000 | 2.9 | 1,370,000 |
Figure 2 – Substantial growth and improvement in MRE quality between Interim and November 2024 Mineral Resource Estimates.
Mine planning and commercial evaluation works to quantify the impact of the increase in the scale and quality of the Bluebird – South Junction MRE are now underway.
Background to the Mineral Resource Estimation
The Yaloginda Mining Centre which hosts Bluebird – South Junction, is located within a goldbearing Archaean greenstone belt situated ~15km south of Meekatharra. The deposits in the area are hosted in a strained and metamorphosed volcanic sequence that consists primarily of ultramafic and high-magnesium basalt with minor komatiite, peridotite, gabbro, tholeiitic basalt and interflow sediments. This sequence was intruded by a variety of felsic porphyry and intermediate sills and dykes.
South Junction is comprised of numerous mineralised zones broadly located on sub-parallel north-northeast-trending structures. These zones from west to east are: Edin Hope, South Junction, Polar Star and Archenar. These zones are offset to the south from the East, Central and Western lodes at Bluebird. Mining in the Murchison district has occurred since 1800’s providing significant confidence in the current geological interpretation of the project.
Geological interpretation of the deposit was carried out using a systematic approach to ensure that the resultant estimated Mineral Resource figure was both sufficiently constrained, and representative of the expected sub-surface conditions. In all aspects of Mineral Resource Estimation, the factual and interpreted geology was used to guide the development of the interpretation. Geological matrixes were established to assist with interpretation and construction of the estimation domains. The structural regime is the dominant control on geological and grade continuity in the Murchison. Lithological factors such as rheology contrast are secondary controls on grade distribution.
Bluebird – South Junction has a mineralised strike length of >1,800m, a lateral extent of +50m and a depth of over 800m to date.
A significant portion of the data used in resource calculations has been gathered from diamond core. Multiple sizes have been used. This core is geologically logged and subsequently halved for sampling. Grade control holes may be whole-cored to streamline the core handling process if required. Face sampling data is also utilised, where each development face / round is horizontally chip sampled. The sampling intervals are domained by geological constraints (e.g. rock type, veining and alteration / sulphidation etc.).
All geology input is logged and validated by the relevant area geologists, incorporated into this is assessment of sample recovery. No defined relationship exists between sample recovery and grade. Nor has sample bias due to preferential loss or gain of fine or coarse material been noted.
Samples undergo fine pulverisation of the entire sample by an LM5 type mill to achieve a 75µ product prior to splitting. QA/QC is currently ensured during the sub-sampling stages process via the use of the systems of an independent NATA / ISO accredited laboratory contractor. The sample size is considered appropriate for the grain size of the material being sampled. The unsampled half of diamond core is retained for check sampling if required.
Sampling is analysed by fire assay as outlined below;
- A 40g – 50g sample undergoes fire assay lead collection followed by flame atomic adsorption spectrometry.
- Independent quality control is ensured via the use of standards, blanks and duplicates. Additionally, the laboratory includes a minimum of 1 project standard with every 22 samples analysed. No significant QA/QC issues have arisen in recent drilling results.
After validating the drillhole data to be used in the estimation, interpretation of the orebody is undertaken in sectional and / or plan view to create the outline strings which form the basis of the three-dimensional orebody wireframe. Wireframing is then carried out using a combination of automated stitching algorithms and manual triangulation to create an accurate threedimensional representation of the sub-surface mineralised body.
Drillhole intersections within the mineralised body are defined, these intersections are then used to flag the appropriate sections of the drillhole database tables for compositing purposes. Drillholes are subsequently composited to allow for grade estimation. In all aspects of resource estimation, the factual and interpreted geology was used to guide the development of the interpretation.
Once the sample data has been composited, a statistical analysis is undertaken to assist with determining estimation search parameters, top-cuts etc. Analysis of individual domains is undertaken to assist with determining appropriate search parameters. Which are then incorporated with observed geological and geometrical features to determine the most appropriate search parameters.
An empty block model is then created for the area of interest. This model contains attributes set at background values for the various elements of interest as well as density, and various estimation parameters that are subsequently used to assist in resource categorisation. The block sizes used in the model will vary depending on orebody geometry, minimum mining units, estimation parameters and levels of informing data available.
Grade estimation is then undertaken. Ordinary kriging estimation method is considered as standard, although in some circumstances where sample populations are small, or domains are unable to be adequately defined, inverse distance weighting estimation techniques will be used. For very minor lodes, the respective median or average grade is assigned. In these circumstances lodes are subsequently classified in lower Mineral Resource confidence categories as appropriate.
Estimation results are validated against primary input data, previous estimates and mining output. The Mineral Resource is then depleted for mining voids and subsequently classified in line with JORC guidelines utilising a combination of various estimation derived parameters and geological / mining knowledge.
Data spacing is variable dependent upon the individual lode under consideration. At Bluebird – South Junction Measured Resources are supported by average drillhole spacing in the range of 15-35m, Indicated from 10-180m and Inferred from 10-200m.
This approach considers all relevant factors and reflects the Competent Person’s view of the deposit. The cut off grades used for the reporting of the Mineral Resources have been selected based on the style of mineralisation, depth from surface of the mineralisation and the most probable extraction technique and associated costs.
At Bluebird – South Junction this has been determined to be 1.5g/t Au.
Likely mining approaches have been considered at the domaining, estimation and classification steps. However, no mining dilution or ore loss has been modelled in the resource model or applied to the reported Mineral Resource Estimate. Nor has metallurgical recovery been applied to the reported Mineral Resource Estimate. These factors are applied during the Ore Reserve generation process.
Figure 3 – South Junction schematic mine layout showing the scale of a typical South Junction stoping panel as compared to a typical stoping panel of the Bluebird mine (Refer Appendix B for detailed drill results).
Looking Forward
Westgold expects significant change in the Ore Reserve for Bluebird - South Junction given the large increase seen in the Measured and Indicated Mineral Resource available for assessment.
The updated MRE is currently undergoing mine planning and commercial evaluation, with the results of this process to be communicated to the market as they come to hand.
Hand-in hand with mine planning works on the updated MRE, accelerated access to the Polar Star portion of the system is being scoped. Studies are currently underway to determine an appropriate second surface access point to the mine to allow for a rapid drill out of the Polar Star area.
This anticipated second access would potentially convert to a long-term production decline in the event that a viable mine plan is produced for Polar Star, deconstraining the current Bluebird
- South Junction mine plan from any future mining at Polar Star.
Westgold has resolved to continue surface drilling at Bluebird - South Junction based upon the continued success in growing the Mineral Resource, and as the orebody remains open at depth and to the south along strike. Drilling will focus on continuing to extend the system footprint, providing infill data to enable executable decision making, and providing a framework to allow infrastructure positioning.
Two surface diamond drilling rigs will be engaged into 2025, and Westgold continues to employ a minimum of two of its underground diamond drill rigs at the mine to achieve these aims.
Figure 4 –South Junction surface drilling.
This announcement is authorised for release by the Board of Directors.
Investor and media relations enquiries
Investor Relations - Australia Investor Relations – North America
Annette Ellis | Investor Relations Manager Rob Buchanan | CPIR [email protected] [email protected] +61 458 200 039 +1 416-309-0600
Competent/Qualified Person Statements
Exploration Results and Mineral Resource Estimates
The information in this release that relates to Exploration results and Mineral Resource Estimates is compiled by Westgold technical employees and contractors under the supervision of Mr. Jake Russell B.Sc. (Hons), who is a member of the Australian Institute of Geoscientists and who has verified, reviewed and approved such information. Mr Russell is a full-time employee of the Company and has sufficient experience which is relevant to the styles of mineralisation and types of deposit under consideration and to the activities which he is undertaking to qualify as a Competent Person as defined in the 2012 Edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (the “JORC Code”) and as a Qualified Person as defined in the CIM Guidelines and National Instrument 43-101
- Standards of Disclosure for Mineral Projects (“NI 43-101”). Mr. Russell is an employee of the Company
and, accordingly, is not independent for purposes of NI 43-101. Mr Russell consents to and approves the inclusion in this release of the matters based on his information in the form and context in which it appears. Mr Russell is eligible to participate in short- and long-term incentive plans of the Company.
The updated MRE has an effective date of 30 June 2024 and was completed by Westgold technical employees and contractors under the supervision of Mr Jake Russell. The key inputs and assumptions are provided in Appendix C to this release including Section 1 – Sampling Techniques and Data, Section 2 – Reporting of Exploration Results, Section 3 – Estimation and Reporting of Mineral Resources and Section 4 – Estimation and Reporting of Ore Reserves.
Ore Reserves
The information in this release that relates to Ore Reserve is based on information compiled by Mr. Leigh Devlin B.Eng. FAusIMM, who has verified, reviewed and approved such information. Mr. Devlin has sufficient experience which is relevant to the styles of mineralisation and types of deposit under consideration and to the activities which they are undertaking to qualify as a Competent Person as defined in the JORC Code and as a Qualified Person as defined in the CIM Guidelines and NI 43-101. Mr. Devlin is an employee of the Company and, accordingly, is not independent for purposes of NI 43-101. Mr. Devlin consents to and approves the inclusion in this release of the matters based on his information in the form and context in which it appears. Mr. Devlin is a full-time senior executive of the Company and is eligible to and may participate in short-term and long-term incentive plans of the Company as disclosed in its annual reports and disclosure documents.
General
Mineral Resources, Ore Reserve Estimates and Exploration Targets and Results are calculated in accordance with the JORC Code. The other technical and scientific information in this release has been prepared in accordance with the Canadian regulatory requirements set out in NI 43-101 and has been reviewed on behalf of the Company by Qualified Persons, as set forth above.
This release contains references to estimates of Mineral Resources and Ore Reserves. The estimation of Mineral Resources is inherently uncertain and involves subjective judgments about many relevant factors. Mineral Resources that are not Ore Reserves do not have demonstrated economic viability. The accuracy of any such estimates is a function of the quantity and quality of available data, and of the assumptions made and judgments used in engineering and geological interpretation, which may prove to be unreliable and depend, to a certain extent, upon the analysis of drilling results and statistical inferences that may ultimately prove to be inaccurate. Mineral Resource estimates may require reestimation based on, among other things: (i) fluctuations in the price of gold; (ii) results of drilling; (iii) results of metallurgical testing, process and other studies; (iv) changes to proposed mine plans; (v) the evaluation of mine plans subsequent to the date of any estimates; and (vi) the possible failure to receive required permits, approvals and licenses.
Forward looking statements
These materials prepared by Westgold Resources Limited include forward looking statements. Often, but not always, forward looking statements can generally be identified by the use of forward looking words such as “may”, “will”, “expect”, “intend”, “believe”, “forecast”, “predict”, “plan”, “estimate”, “anticipate”, “continue”, and “guidance”, or other similar words and may include, without limitation, statements regarding plans, strategies and objectives of management, anticipated production or construction commencement dates and expected costs or production outputs.
Forward looking statements inherently involve known and unknown risks, uncertainties and other factors that may cause the Company’s actual results, performance and achievements to differ materially from any future results, performance or achievements. Relevant factors may include, but are not limited to, changes in commodity prices, foreign exchange fluctuations and general economic conditions, increased costs and demand for production inputs, the speculative nature of exploration and project development, including the risks of obtaining necessary licenses and permits and diminishing quantities or grades of reserves, political and social risks, changes to the regulatory framework within which the Company operates or may in the future operate, environmental conditions including extreme weather conditions, recruitment and retention of personnel, industrial relations issues and litigation.
Forward looking statements are based on the Company and its management’s good faith assumptions relating to the financial, market, regulatory and other relevant environments that will exist and affect the Company’s business and operations in the future. The Company does not give any assurance that the assumptions on which forward looking statements are based will prove to be correct, or that the Company’s business or operations will not be affected in any material manner by these or other factors not foreseen or foreseeable by the Company or management or beyond the Company’s control.
Although the Company attempts and has attempted to identify factors that would cause actual actions, events or results to differ materially from those disclosed in forward looking statements, there may be other factors that could cause actual results, performance, achievements or events not to be as anticipated, estimated or intended, and many events are beyond the reasonable control of the Company.
In addition, the Company’s actual results could differ materially from those anticipated in these forward looking statements as a result of the factors outlined in the “Risk Factors” section of the Company’s continuous disclosure filings available on SEDAR+ or the ASX, including, in the Company’s current annual report, half year report or most recent management discussion and analysis.
Accordingly, readers are cautioned not to place undue reliance on forward looking statements. Forward looking statements in these materials speak only at the date of issue. Subject to any continuing obligations under applicable law or any relevant stock exchange listing rules, in providing this information the Company does not undertake any obligation to publicly update or revise any of the forward-looking statements or to advise of any change in events, conditions or circumstances.
Appendix A – History of South Junction
Mineralisation was discovered at South Junction in mid-1989 by St Barbara Mining. South Junction was subsequently mined as an open pit from June 1990 through to the early 2000’s. Total gold production for the open pit phase of operation at South Junction was in excess of 400,000 ounces. However, since open pit mining concluded activity at South Junction has effectively been dormant.
To the immediate north of South Junction, the Bluebird deposit has been mined at various stages. This mining was dominated by small scale underground mining operations and open pits until the turn of the century after which St Barbara, Mercator Gold and Reed Resources mined 485,000 ounces between 2000 – 2013 via substantial open pit operations.
Figure 5 – Yaloginda gold camp is absent deep drilling outside of Bluebird – South Junction.
In late 2019, Westgold commenced underground operations at Bluebird which subsequently produced over 162koz of gold. This brings the total recorded Bluebird production to 809koz and the combined Bluebird – South Junction production to 1.20Moz.
Combining this with the Mineral Resource remaining, Bluebird – South Junction can be considered a +2Moz system.
Murchison Overview
Westgold’s Murchison business incorporates four underground mines, three processing plants and the Great Fingall development project near Cue. Westgold’s Bluebird processing hub is the largest of its three Murchison processing hubs and is located approximately 15km southwest of the town of Meekatharra (see Figure 6).
The Bluebird underground mine is the primary ore source feeding the 1.4-1.8Mtpa Bluebird processing plant. Surface stockpiles and supplementary ore from Cue is trucked to Bluebird to maintain processing throughputs, with these volumes reducing as the Bluebird-South Junction mine expands.
Figure 6 – Westgold’s Murchison Asset Map.