Alkane Extends High Grade Gold Trend at Brunswick South

Program Summary

Brunswick South Assay Highlights

Note. ETW refers to the estimated true width of the veining.

Alkane Managing Director & CEO, Nic Earner, said:

“Focused extension and infill drilling at Brunswick South over the previous year has produced highly encouraging results. This newly defined deposit not only contains pockets of high gold endowment, but critically a significant quantity of antimony. Excitingly Brunswick South can be brought online without extensive access requirements as it is situated 200m from existing development. We are commencing development towards Brunswick South in the current quarter and are looking to establish it as a primary production source for Costerfield.”

Costerfield Gold-Antimony Field

Alkane Resources Ltd 100%

The Costerfield gold-antimony deposit was discovered in 1861, antimony having been already identified in the district as early as 1853 as prospectors attracted 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 from leases at the northern end of the field; the Costerfield (Main), Bombay and Minerva mines. Production 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 commenced underground operations at Augusta, at the southern end of the field. AGD’s Costerfield operation was purchased by Mandalay Resources in 2010, and extraction of the vertically continuous vein system has progressively moved north beneath the Costerfield, Minerva and Bombay group of mines, where Mandalay’s high-grade Youle and Shepherd lodes were discovered.

The Brunswick deposit was discovered in early 1863 (initially called the New Brunswick) and saw limited prospecting through the early life of the field. It was not until the investigations of Mid-East Minerals and the Geological Survey of Victoria between 1966-1971 that the extent of mineralisation at the deposit was intently explored via diamond drilling and the sinking of an exploratory shaft which saw the development of two levels later throughout the 1970s. Australian Gold Development later developed an open cut mine on the Brunswick Reef, extracting oxide gold in 1995-1997. Mandalay Resources mined the Brunswick Reef below the historic workings via underground development in 2018, while developing north from Cuffley to the newly discovered Youle Deposit.

Figure 1. Regional map of the Costerfield Project in GDA2020 grid showing Alkane tenements and the main corridors of mineralisation identified, highlighting the location of the Brunswick South deposit.

A small, near-surface resource delineated by AGD at the time of open-cut mining exists approximately 400m south of the main deposit, which indicated strong structural continuity for the Brunswick deposit outside of the mined area. This Brunswick South deposit remained resistant to significant extension via diamond drilling down-dip, until mid-2025 when a campaign of three diamond holes all intersected high-grade mineralisation over the span of 175m just below the level of the Cuffley-Brunswick access, prompting immediate intensive infill and extension drilling (ASX announcement 15 October 2025 titled ‘Costerfield Resource and Reserve Statement’). The previous high grade intercepts included:

Deposit Geology

The Brunswick Deposit is located at the apex of the Costerfield Dome, between the Augusta and Youle deposits at Costerfield and offset approximately 500m west of the main corridor of mineralisation. The Costerfield Formation host rocks are uniformly siltstones above approximately 900RL (300m below surface), transitioning to thin bedded and fine-grained turbidites below this level. The mineralisation in the north is hosted by a vertical shear that occupies the hinge of the gentle Brunswick Anticline, crossing to an adjacent parasitic syncline in the new southern portion of the deposit. Mineralisation in the vertical, shear hosted part of the deposit tends to be antimony-rich and proportionally deficient in quartz compared to most other worked Costerfield veins, while retaining gold grades comparable to the rest of the field.

North-west trending, steeply dipping faults intersect the Brunswick shear and delineate high-grade shoots within the orebody. This relationship is well understood in the northern part of the deposit where open-cut mining took place and is expected to be important in the south. Bedding-parallel laminated quartz veins and faults are common and influence ore grades at a local scale, the lode structure typically crosses these structures without significant offset or deviation until the Kiwi Fault is reached. The Kiwi Fault is a bedding parallel, laminated quartz fault where seen on the western limb of the Brunswick Anticline, which increases in late, brittle damage and bifurcates into a duplex stack (with the Rooster Fault as its footwall) as it flattens out over the crest of the anticline. In the northern end of the Brunswick deposit where the Brunswick shear intersects the Kiwi Fault where it is almost horizontal, mineralisation splits into several parallel, vertical veins bound between the Kiwi and Rooster fault planes that can achieve high grades albeit with limited ore panel heights. In the new southern area where the Brunswick Shear intersects the fault in a position where it dips moderately westward, mineralisation appears to roll into the fault plane and continue down-dip in a fashion analogous to the Kendal vein system and high-grade Youle Lode in the northern end of the Costerfield Main Corridor. The mineralisation so far encountered proximal to and within the Kiwi Zone differs significantly to the antimony-rich shear seen above, being predominantly free from stibnite and rich in quartz. The gold-rich quartz veining is multiple-generation, containing early brecciated quartz healed by a later quartz matrix.

Below the Rooster Fault, low-tenor mineralisation in the northern part of the deposit continues down dip in a vertical shear of similar character to that above, offset approximately 80m to the west. This area to the south has not been drill tested to date, and the mineralised Kiwi Fault plane is still being explored to determine the extent of mineralisation.

Drilling Results

Since the previous release, 91 extension and infill holes have been completed, totalling 28,421m of diamond drill core. In addition to extending the new high-grade zone, further infill of the existing historic resource was conducted to identify possible economic continuity between the two areas, which appears to be the case. Of the drilled holes, 10 intercepts have resulted in assays grading above 10g/t AuEq¹ over a diluted mining width of 1.8m:

The drilling in hand has identified two main economic zones:

Additional ore-grade intercepts were made centrally within the existing near-surface resource, building confidence in the economic extents of the deposit as a whole. A general trend observed amongst the economic-grade intercepts was the transition from antimony-rich intercepts in the upper level of the deposit to gold dominated with lesser antimony approaching and within the Kiwi Zone. This trend is also observed in the Youle/Shepherd system at a deeper level, which suggests that the zonation may occur on a per-deposit basis rather than a field-wide gradient.

Many intercepts of smaller-scale splay veins associated with the Brunswick South structure were found, the most notable of which was in BD463W2 with 288g/t Au over 0.16m (ETW 0.14m) located approximately 10m west of the main Brunswick South structure. These splays are likely to be systematically followed up with additional holes from underground drilling platforms when mining reaches Brunswick South.

In addition to intercepts made on the main system a previously unknown line of mineralisation was identified near surface, approximately 200 metres west of, and striking parallel to, the Brunswick deposit. This Brunswick West target appears to dip 60-70 degrees east and is projected to intercept the Kiwi Zone down-dip of where currently tested. While mineralisation is sporadic on the structure (small-scale structural complexity and low drilling angles are contributing factors), an intercept of 8.4g/t gold and 1.3% antimony over 0.32m (ETW 0.31m) was drilled in BD475 and is the deepest traverse of the line at ~220m below surface.

Figure 2. Long Section of the Brunswick South deposit with major vein target envelopes displayed, recent drill traces and > 6g/t AuEq new intercepts labelled. Older significant drill intercepts are displayed as smaller, unlabelled icons.

Figure 3. Brunswick South Deposit Plan Section with recent drill traces and > 6g/t AuEq new intercepts labelled. Older significant drill intercepts are displayed as smaller, unlabelled icons.

Figure 4. Cross section of the Brunswick South deposit with the Costerfield Leapfrog geology model sliced at 5200N, where the greatest number of new high-grade intercepts are located. The spread of intercepts away from the model slice is due to the strike of the Brunswick South deposit being approximately 15 degrees east of mine grid north (as seen in Figure 3).

Figure 5. Core tray photograph of the Brunswick South intercept of BD468 (50.1g/t gold and 26.2% antimony over 2.17m - ETW 1.08m) exhibiting the shear-associated, stibnite rich character typical to the Brunswick deposit above the Kiwi Zone. Zonation of sulphide wallrock alteration, from fine grained arsenopyrite proximal to the high grade veins to more distal blebby aggregates of pyrite may also be discerned. Photomicrographs of gold clusters within quartz and stibnite from the richest segment of the intercept are also shown.

Figure 6. Tray photograph and gold grades of the Kiwi Zone in drillhole BD513. The mineralisation is quartz-dominated in contrast to the upper Brunswick South structure, and occurs at a low angle to the west-dipping bedding, following the Kiwi Fault plane. This is dissimilar to K-R mineralisation beneath Brunswick Main where vertical veins are bound between the hangingwall and footwall planes of the fault slice due to the flattening of the Kiwi and Rooster Fault structures, being more aligned with a Youle-like geometry.

Future Plans

The information presented in this release has been integrated into the Costerfield mine schedule, and the commencement of capital development to access the area is scheduled for Q3 2026. Several targets have emerged as priority for further testing, which include:

An updated Brunswick South resource will be announced as part of Alkane’s upcoming Resource and Reserves Statement.

This document has been authorised for release to the market by Nic Earner, Managing Director & CEO.

ABOUT ALKANE ‐ www.alkres.com ‐ ASX:ALK | TSX: ALK | OTCQX: ALKRY

Alkane (ASX:ALK; TSX:ALK; OTCQX:ALKRY) is an Australia-based gold and antimony producer with a portfolio of three operating mines across Australia and Sweden. The Company has a strong balance sheet and is positioned for further growth.

Alkane’s wholly owned producing assets are the Tomingley open pit and underground gold mine southwest of Dubbo in Central West New South Wales, the Costerfield gold and antimony underground mining operation northeast of Heathcote in Central Victoria, and the Björkdal underground gold mine northwest of Skellefteå in Sweden (approximately 750 km north of Stockholm). Ongoing near-mine regional exploration continues to grow resources at all three operations.

Alkane also owns the very large gold-copper porphyry Boda-Kaiser Project in Central West New South Wales and has outlined an economic development pathway in a Scoping Study. The Company has ongoing exploration within the surrounding Northern Molong Porphyry Project and is confident of further enhancing eastern Australia’s reputation as a significant gold, copper and antimony production region.

Competent Persons Statement

Certain information in this announcement relating to Exploration Results has been previously released to the ASX. Alkane confirms that it is not aware of any new information or data that materially affects the information included in those market announcements and that all material assumptions and technical parameters underpinning the estimates and Exploration Results in those announcements continue to apply and have not materially changed.

The information in this report that relates to the Costerfield Exploration Results is based on, and fairly represents, information compiled and verified by Mr Chris Davis. Mr Davis is a Chartered Professional (Geology) of the Australasian Institute of Mining and Metallurgy (MAusIMM CP(Geo)), and a Member of the Australian Institute of Geoscientists (MAIG).

Mr Davis has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the “Australian Code for Reporting of Exploration Results, Mineral Resources, and Ore Reserves” (JORC Code).

For the purposes of National Instrument 43-101 – Standards of Disclosure for Mineral Projects (‘NI 43-101’), the scientific and technical information contained in this announcement relating to the Costerfield Exploration Results has been prepared under the supervision of, and approved by, Mr Chris Davis, who is a “qualified person” as defined in NI 43-101. Mr Davis is employed by Alkane as Chief Geologist and, as an employee of Alkane, is not considered independent of Alkane within the meaning of NI 43-101.

Mr Davis consents to the inclusion in this report of the matters based on his information in the form and context in which they appear.

Cautionary Note Regarding Forward-Looking Information and Statements

This announcement contains certain forward-looking information and forward-looking statements within the meaning of applicable securities legislation and may include future-oriented financial information or financial outlook information (collectively Forward-Looking Information). Actual results and outcomes may vary materially from the amounts set out in any Forward-Looking Information. As well, Forward-Looking Information may relate to: future outlook and anticipated events; expectations regarding exploration potential; production capabilities and future financial or operating performance, including AISC, investment returns, margins and share price performance; production and cost guidance and the timing thereof; issuing updated resources and reserves estimate and the timing thereof; the potential of Alkane to meet industry targets, public profile and expectations; and future plans, projections, objectives, estimates and forecasts and the timing related thereto.

Forward-Looking Information is generally identified by the use of words like "will", "create", "enhance", "improve", "potential", "expect", "upside", "growth" and similar expressions and phrases or statements that certain actions, events or results "may", "could", or "should", or the negative connotation of such terms, are intended to identify Forward-Looking Information.

Although Alkane believes that the expectations reflected in the Forward-Looking Information are reasonable, undue reliance should not be placed on Forward-Looking Information since no assurance can be provided that such expectations will prove to be correct. Forward-Looking Information is based on information available at the time those statements are made and/or good faith belief of the officers and directors of Alkane as of that time with respect to future events and are subject to risks and uncertainties that could cause actual results to differ materially from those expressed in or suggested by the Forward-Looking Information. Forward-Looking Information involves numerous risks and uncertainties. Such factors include, without limitation: risks relating to changes in the gold and antimony price.

Forward-Looking Information is designed to help readers understand Alkane’s views as of that time with respect to future events and speak only as of the date they are made. Except as required by applicable law, Alkane assumes no obligation to update or to publicly announce the results of any change to any forward-looking statement contained or incorporated by reference herein to reflect actual results, future events or developments, changes in assumptions or changes in other factors affecting the Forward-looking Information. If Alkane updates any one or more forward-looking statements, no inference should be drawn that the company will make additional updates with respect to those or other Forward-looking Information. All Forward-Looking Information contained in this announcement is expressly qualified in its entirety by this cautionary statement.

Disclaimer

Alkane has prepared this announcement based on information available to it. No representation or warranty, express or implied, is made as to the fairness, accuracy, completeness or correctness of the information, opinions or conclusions contained in this announcement. To the maximum extent permitted by law, none of Alkane, its directors, officers, employees, associates, advisers and agents, nor any other person accepts any liability, including, without limitation, any liability arising from fault or negligence on the part of any of them or any other person, for any loss arising from the use of this announcement or its contents or otherwise arising in connection with it.

This announcement is not an offer, invitation, solicitation, or other recommendation with respect to the subscription for, purchase or sale of any security, and neither this announcement nor anything in it shall form the basis of any contract or commitment whatsoever.

APPENDIX 1 – Tabulated Drilling Results

Significant intercepts from the Brunswick South infill and growth drilling programs at Costerfield

Notes
1. The AuEq (gold equivalent) grade is calculated using the following formula:

AuEq =Au (g/t) + 2.39 x Sb (%)AuEq g per t=Au g per t+Sb%×

And the AuEq factor of 2.39 is calculated:

Prices and recoveries used: Au $/oz = 2,500; Sb $/t = 19,000; Au Recovery = 91% and; Sb Recovery = 92%

2. Composites that are not interpreted to be connected to a major vein and are below 1 g/t AuEq when diluted to 1.8m are not considered significant and are not recorded here.

Drill hole collar details from the Brunswick South drilling program at Costerfield:

Notes:

Appendix 2 - JORC Code, 2012 Edition – Table 1

Section 1 Sampling Techniques and Data

Section 2 Reporting of Exploration Results

Criteria listed in the Section 1 also apply to this section.

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

¹ AuEq calculated with assumptions: Au $/oz = 2,500; Sb $/t = 19,000; Au Recovery = 91% and; Sb Recovery = 92%

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