Alkane Advances Near-Mine Kendal Deposit with High Grade Antimony-Gold Intercepts at Costerfield
CONTACT: NIC EARNER, MANAGING DIRECTOR & CEO, ALKANE RESOURCES LTD, TEL +61 8 9227 5677
INVESTORS & MEDIA: NATALIE CHAPMAN, CORPORATE COMMUNICATIONS MANAGER, TEL +61 418 642 556
Level 4, 66 Kings Park Rd, West Perth WA 6005, AUSTRALIA (PO Box 768, West Perth WA 6872, AUSTRALIA)
Telephone: +61 8 9227 5677 alkres.com [email protected]
INVESTOR ANNOUNCEMENT and MEDIA RELEASE
25 February 2026
Alkane Advances Near-Mine Kendal Deposit with
High Grade Antimony-Gold Intercepts at Costerfield
Perth, Western Australia - Alkane Resources Limited (ASX: ALK; TSX: ALK; OTCQX: ALKRY) (‘Alkane’
or ‘the Company’) is pleased to announce the latest exploration results for the extension and infill drilling
of the Kendal deposit adjoining the curr ently mined Youle deposit at its Costerfield Operation in central
Victoria, Australia.
Program Summary
The Kendal system is the antimony-rich, up-dip continuation of the high- grade Youle and Shepherd
deposits, where mining is currently underway at Costerfield.
Infill and extension drilling over the past year has si gnificantly extended the known size of the vein
system, both offset from and adjacent to historic mine workings. Whilst historic mining has been
undertaken in the area, this latest drilling has revealed significant veining that was undiscovered when
the mine was active between 1861 and 1939.
The Kendal veins contain areas of very high gold and antimony grade that have historically correlated
with higher production rates.
Development to access the newly extended Kendal system began in late 2025 and is ongoing as
extension drilling continues.
An animation summarising these results will be available at alkres.com
Kendal Assay Highlights
From the 501 vein to the south and immediately above Youle:
o 132.2 g/t gold and 19.8 % antimony ov er 1.94m (ETW 1.04m) in PD222
o 25.3 g/t gold and 42.8 % antimony over 1.71m (ETW 0.97m) in PD220
o 13.5 g/t gold and 22.1% antimony over 2.67m (ETW 1.24m) in AG023
o 25.4 g/t gold and 8.3 % antimony over 1.28m (ETW 1.12m) in BC437
o 34.1 g/t gold and 12.9 % antimony over 0.76m (ETW 0.69m) in BC112A
From the 520 vein spanning greater than 500m in strike and locally 200m in height.
o 267.5 g/t gold and 5.6 % antimony over 2.3 m (ETW 1.22m) in BC464
o 143.7 g/t gold and 10.8 % antimony over 1.35 m (ETW 1.06m) in BC463
o 18.2 g/t gold and 11.9 % antimony ov er 2.44 m (ETW 1.92m) in BC466A
Alkane Managing Director & CEO, Nic Earner, said: “The drilling results obtained from the Kendal deposit
over the past year demonstrate the large potential rema ining for significant high-grade mineralisation at
shallow levels near to the Costerfield mine. Accessing and mining the newly defined mineralisation is a top
priority for the Costerfield team and should provide the processing plant with an additional source of high-
grade gold and antimony ore for some time to come.”
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Costerfield Deposit
Alkane Resources Ltd 100%
The Costerfield antimony-gold deposit was discovered in 1861. Antimony had already been identified in
the district as early as 1853, as prospectors attracte d to the McIvor (Heathcote) alluvial gold rush began
to explore the surrounding hills for the primary deposits. Several lodes along a 3km corridor were rapidly
opened up, the bulk of historical production coming fr om leases at the northern end of the field; the
Costerfield (Main), Bombay and Minerva mines. Product ion from these mines primarily took place in two
phases, between 1861-1883 and 1903-1924, and a short-lived attempt at redeveloping the mine occurred
between 1933-1939.
Modern mining has been continuous since 2006, when Australian Gold Development (AGD) commenced
underground operations at Augusta, at the southern end of the field. AGD’s Costerfield operation was
purchased by Mandalay Resources in 2010, and extracti on of the vertically cont inuous vein system has
progressively moved north beneath the Costerfield, Minerva and Bombay group of mines, where the high-
grade Youle and Shepherd lodes were discovered.
Mandalay Resources merged with Alkane Resources in 2025.
As mining of the underlying vein systems has progressed, it has been recognised that significant amounts
of untested mineralisation remain at the level of the historic mines (wit hin 300m of surface) both laterally
and within the footprint of the workings. This is primarily due to the structural complexity of the ore system,
which consists in places of sheeted vein swarms that can be difficult to interpret along strike without modern
methods, including close-spaced drilling that was unavailable to the historic miners.
Figure 1. Regional map of the Costerfield Project in GDA grid showing Alkane tenements and the main corridors
of mineralisation identified.
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Alkane Advances Near-Mine Kendal Deposit with High Grade Antimony-Gold Intercepts at Costerfield – 25 February 2026
Deposit Geology and the Kendal System
The Kendal deposit (and the Costerfield mine) is lo cated on the hinge and western flank of the north-
striking Costerfield Anticline which forms the culmination of the Costerfield Dome. The Costerfield Anticline
is asymmetrical with a steeply dipping eastern limb, and a gentle dip to the western limb. Numerous smaller
scale parasitic folds and warps occupy the broad hinge zone, which often exhibit a weak axial cleavage or
parting fabric in the host siltstone. It is this fabric which appears to be the dominant structural host or control
for the Kendal veins.
Numerous bedding parallel faults, often containing early-generation laminated quartz veins bisect the
system and act as a significant control on grade. Individual veins appear to be offset to the west with depth
across these faults, although vein development clearl y post-dates fault activity and often can be seen to
run along the shallow-dipping faults in a healed manner. Down-dip, the Kendal mineralisation encounters
a major west-dipping thrust fault and becomes Youle Lode, which persists downward until the thrust fault
begins to shallow, at which point mineralisation break s back out into a vertical vein system mirroring
Kendal, called Shepherd. The Kendal system does not appear to persist into the eastern limb of the greater
Costerfield Anticline, which is consistent with other vertical vein systems at Costerfield, potentially due to
the lack of cleavage development and small angle between bedding and veining.
Figure 2. Geological cross section of the Costerfield gold-antimony ve in system at mine northing 7200N,
showing the Kendal vein system’s position in the Costerfield Anticline and its relationship with the below Youle
and Shepherd veins which are currently mined.
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2025 Drilling Program
When the upper portion of Youle Lode was first ac cessed in 2018 by Mandalay Resources, it was
confirmed that the lode system was upwardly contin uous, bifurcating and steepening over subhorizontal
faulting to form the Kendal system. Over the period of mining, occasional diamond drill holes were placed
through Kendal and the adjacent historic mines, which gradually built confidence that a significant amount
of mineralisation still exis ted above the modern mini ng level. In September 20 24, Mandalay Resources
issued a TSX announcement, describing the first porti on of the Kendal system (the 580 Vein) to be
thoroughly tested with modern drilling. The drilling desc ribed in this update builds on that work and has
tested along the length of the three main historic mines. The bulk of remaining mineralisation identified to
date is located adjacent to the Minerva and Coster field mines, although continuity of the system is
demonstrated all the way through to the Bombay mine in the south.
Significant amounts of historical drilling have tested the near-surface portion of the Kendal system,
including a campaign of RC percussion drilling conducted by Australian Gold Development in 1995-1996.
These historic intercepts have not been verified or validated by Alkane, and their positions are displayed
in the release figures due to their relevance to the Kendal target area at height and are indicatory only as
support to the geological interpretation.
Drilling Results
With the drill information to date in hand, a total of 25 individual ve ins have been delineated by Alkane
through the Kendal system, building on historical modelling with the inclusion of this program’s drilling data,
providing linking intercepts between the three historic al mines, and significant extension for some. The
Kendal veins extend over a strike of 600m, and some individual veins can be traced for most of this length,
for example the 520 vein, which has been interpreted over a length of 500m, with up to 200m of vertical
extent. The width of the Kendal system averages around 70m for much of its strike.
The antimony content of the Kendal system, as tested in the program, is significantly higher than that of
the Shepherd system, which is a main source of ore for the Costerfield operation, and also demonstrates
very high gold content (refer to Appendix 1 for a complete list of significant intercepts from the current drill
program).
Many exceptional intercepts were achieved during the program and integrated into the Costerfield
geological model. Below are some highlights in addition to those stated above:
From the 501 vein:
o 29.6g/t gold and 50.5% antimony over 0.72m (ETW 0.26m) in PD232
o 40.6g/t gold and 40.4% antimony over 0.4m (ETW 0.26m) in BC308
o 30.1g/t gold and 13.4% antimony over 0.67m (ETW 0.55m) in BC438
o 25g/t gold and 28.1% antimony over 0.67m (ETW 0.36m) in BC328
o 50g/t gold and 48.3% antimony over 0.21m (ETW 0.2m) in KD529
o 5.3g/t gold and 5.3% antimony over 1.83m (ETW 1.78m) in KD698
From the 519 vein:
o 52.3g/t gold and 43.1% antimony over 0.34m (ETW 0.29m) in BC468
o 138g/t gold and 7.7% antimony over 0.27m (ETW 0.21m) in BC143
From the 523 vein:
o 39.4g/t gold and 7.5% antimony over 0.85m (ETW 0.68m) in BC438
o 261g/t gold and 32.5% antimony over 0.15m (ETW 0.09m) in BC416
From the 545 vein:
o 18.1g/t gold and 12.9% antimony over 1.97m (ETW 1.45m) in BC453
o 84.4g/t gold and 35.2% antimony over 0.41m (ETW 0.3m) in BC470
From the 587 vein:
o 7.5g/t gold and 5.9% antimony over 2.45m (ETW 1.93m) in BC311
From the 590 vein:
o 13.6g/t gold and 16.4% antimony over 2.22m (ETW 1.37m) in BC418
From the 595 vein:
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Alkane Advances Near-Mine Kendal Deposit with High Grade Antimony-Gold Intercepts at Costerfield – 25 February 2026
o 42.2g/t gold and 35.9% antimony over 0.45m (ETW 0.3m) in BC477
o 41.2g/t gold and 41.8% antimony over 0.32m (ETW 0.23m) in BC465
The 501 vein, which is near modern infrastructure and has recently been accessed for mining, hosts many
of the recent (and earlier, unreport ed) standout intercepts. In addition to the above, several other highly
promising intersections were recorded adjacent to the modelled veins:
o 275g/t gold and 0.1% antimony over 0.49m (ETW 0.4m) in BC125
o 187g/t gold and 37.8% antimony over 0.35m (ETW 0.32m) in BC313
o 54.2g/t gold and 50.8% antimony over 0.55m (ETW 0.44m) in BC311
o 165g/t gold and 34.8% antimony over 0.27m (ETW 0.24m) in BC312
It is anticipated that these intercepts will be integrated into the existing geological model as future drilling
adds additional context.
Figure 3. Costerfield / Kendal area plan view with major Kendal vein best fit traces displayed (green), cross
section positions (yellow lines), 2025 drill traces and >10g/t AuEq intercepts labelled. Historic Kendal intercept
positions are shown as faded circle.
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Alkane Advances Near-Mine Kendal Deposit with High Grade Antimony-Gold Intercepts at Costerfield – 25 February 2026
Figure 4. Long Section of the Kendal 501 Vein with high grade assays highlighted. The lower portion of the 501
vein has already been accessed by Alkane, and diluted face grades are shown alongside drilling intercepts.
Figure 5. Long Section of the Kendal 520 Vein with high grade 2025 assays highlighted. The section shows the
strong continuity of the Kendal system outside of the historically mined sections, both vertically and along strike.
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The veins are dominantly single-gen eration, typically consisting of quartz and carbonate, grading to
massive stibnite towards the centre line of the vein s. Gold can be coarse and present in any part of the
vein, and “rusty” gold is often noted, colloform free gold left after the chemical breakdown of the mineral
aurostibite, which is common at Costerfield. The veins are surrounded by a narrow (>2m) wallrock sulphide
alteration of pyrite and arsenopyrite.
Figure 6. Drill core photos from BC418 (590 Vein) showin g the nature of veining with individual assay grades
of the samples. Composited interval graded 13.6g/t gold and 16.4% antimony over 2.22m (ETW 1.37m).
Figure 7. Photo of drill core from BC463 (520 Vein) show ing the sheeted nature of the ore veins. Note the
oxidised interval adjacent to the intercept signifies an historical stope adjacent to the in situ high-grade veins.
Composited interval graded 143.7g/t gold and 10.8% antimony over 1.35m (ETW 1.06m).
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Alkane Advances Near-Mine Kendal Deposit with High Grade Antimony-Gold Intercepts at Costerfield – 25 February 2026
Figure 8. Cross section looking north at mine northing 7120N showing Kendal veins in cross section and drill
intercepts between 7000N and 7135N. 2025 drill inters ections grading over 10g/t AuEq when diluted to 1.8m
are labelled. The historic Costerfield Main shaft and workings can be seen centred at 15,500E, and the modern
Alkane development offset to the west and depth. Note the average depth of the Kendal mineralisation ascends
to the north with the plunge of the anticline.