ASX Announcement Westgold Resources Limited
ASX Announcement
Westgold Resources Limited
ABN 60 009 260 306
ASX: WGX | TSX: WGX | OTC: WGXRF
westgold.com.au
T: +61 8 9462 3400
Level 6, 200 St Georges Terrace
Perth WA 6000
PO Box 7068, Cloisters Square WA 6850
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.
Bluebird - South Junction Mineral Resource Grows to 1.4Moz
18 November 2024
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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 110k t a month mine with a highly efficient tra nsverse primary / secondary mining
sequence. This transition is buil t 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 I ndicated
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 Goldfield s preliminary work s 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 Cow an
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 Mineral Resource Grows to 1.4Moz
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Bluebird – South Junction - A Rapid Growth Story
The South Junction lodes at Bluebird (Figure 5 ) were identified as a prio rity growth opportunity
following the results of initial drill testing in early 2023 (r efer 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
(g/t Au) Ounces
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
Bluebird - South Junction Mineral Resource Grows to 1.4Moz
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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
(g/t Au) Ounces
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
(g/t Au) Ounces
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.
Bluebird - South Junction Mineral Resource Grows to 1.4Moz
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Background to the Mineral Resource Estimation
The Yaloginda Mining Centre which hosts Bluebird – South Junction, is located within a gold -
bearing 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 regi me 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 s ampling 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 un-
sampled half of diamond core is retained for check sampling if required.
Bluebird - South Junction Mineral Resource Grows to 1.4Moz
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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, t he 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 three -
dimensional 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. A nalysis 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. O rdinary 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.
Bluebird - South Junction Mineral Resource Grows to 1.4Moz
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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).
Bluebird - South Junction Mineral Resource Grows to 1.4Moz
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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.