PERTH, Australia, Aug. 23, 2026 (GLOBE NEWSWIRE) -- Alkane Resources Limited (ASX: ALK; TSX: ALK; OTCQX: ALKRY) (‘Alkane’ or ‘the Company’) is pleased to announce the latest exploration results highlighting the discovery of a new high-grade zone of the Cuffley Lode, and drilling results from the Sub-KC domain at depth below the Augusta mine and the Costerfield property in Victoria, Australia
Program Summary
- 23 new holes have been drilled in an unmined area between the historical Cuffley north and south high-grade grade panels, and 17 additional holes have targeted the Sub KC domain at depth below the deposit
- A new grade pod with areas of very high grade gold and antimony was identified in the Cuffley infill area, in a sparsely drilled zone previously thought to contain low grade due to the influence of a crosscutting fault
- Additional high grade infill intercepts have made in the Sub KC system, and the first target testing holes looking for repetitions of the structural setup have been drilled
- The Cuffley pod is readily accessible from existing infrastructure and is being incorporated into the mine schedule
Assay Highlights
- From Cuffley
- 580.9g/t gold and 24% antimony over 0.61m (ETW 0.54m) in AD270
- 168.9g/t gold and 33.5% antimony over 0.9m (ETW 0.78m) in AD265
- 60.1g/t gold and 15.2% antimony over 1.26m (ETW 1.17m) in AD292
- 124g/t gold and 48.6% antimony over 0.23m (ETW 0.22m) in AD275
- From Sub KC
- 28.2g/t gold and 0% antimony over 0.99m (ETW 0.82m) in CSK044
- 73.2g/t gold and 18.8% antimony over 0.19m (ETW 0.18m) in CSK043
- 192g/t gold and 0% antimony over 0.17m (ETW 0.07m) in CSK043
- 16.1g/t gold and 12.7% antimony over 0.37m (ETW 0.34m) in CSK048
Alkane Managing Director & CEO, Nic Earner, said:
“This discovery of unmined high-grade material directly adjacent one of Costerfield’s top-shelf historical orebodies showcases the importance of Alkane’s directive of revisiting and challenging old models and preconceptions surrounding mineralisation to extract value. We will continue seeking this new mineralisation alongside generating new targets within our leases.”
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. Firstly from the initial Augusta series of lodes, to Cuffley and N Lode in 2014 and the Brunswick in 2018. Costerfield’s current locus of mining is beneath the Costerfield, Minerva and Bombay group of mines, where Mandalay’s high-grade Youle and Shepherd lodes were accessed in 2019.
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 Cuffley and Sub KC deposits.
Deposit Geology
The Cuffley and Sub KC deposits are found within the Central Corridor of deposits at Costerfield. This corridor approximately traces the apex of the Costerfield Dome, a structural high which consists of Silurian marine siltstones with turbiditic intervals becoming common towards the base of the known sequence. The Cuffley Lode occupies a vertical shear, running along a N-S field-scale anticline (Cuffley Anticline) next to the Augusta Deposit. The lode sits on the gently dipping western edge of its 200m-wide hinge zone, N Lode occupies the corresponding eastern axial zone with a steep east-dipping limb. Mineralisation at Cuffley is of the “classic” Costerfield style, consisting of quartz-carbonate veining grading to massive stibnite, gold being found in both quartz and stibnite. Updip, the Cuffley lode is truncated by the Mamushi/Flat Fault set, which offsets the mineralisation above eastward by approximately 40m, where it is known as the historical Alison deposit. The Alison mineralisation is itself bounded updip by the major west-dipping Adder Fault thrust. The footwall of the Cuffley system is delineated by the similarly west-dipping King Cobra Fault thrust, which breaches and offsets the Cuffley anticline.
Down-dip from Cuffley, westward along the King Cobra Fault plane, mineralisation resumes with the Sub-KC deposit. Sub-KC occupies the steeply dipping east limb of the continuation of the Cuffley Anticline. If the approximately 300m of offset along the fault plane is restored, reconstructing the anticline and stratigraphy, the Sub-KC deposit correlates very well with the downward continuation of N Lode. The axis of the anticline hosts a strong gougey shear termed the Lyre Fault, which merges into the King Cobra Fault forming the hangingwall of the main Sub-KC domain between them. The Lyre Fault exhibits some clear post-mineralisation movement, evidenced by clasts of mineralised vein material in fault gouge recovered in earlier Sub-KC drilling. Most mineralisation associated with Sub KC sits in the immediate footwall of the Lyre Fault and reduces in tenor at distance from the fault plane. Strike control is not fully understood at this stage of drilling due to limited drilling orientations, but appear to be related to north-east trending splays from the Lyre Fault somewhat similar in nature to the East Fault at Cuffley. The most important of these are the Bird and Bustard Faults, represented on the Sub-KC long section below.
The veins of the Sub-KC deposit generally fall into three categories:
- Early, laminated bedding parallel quartz veins (Figure 7, CSK043), reactivated and dilated during the mineralisation, the later quartz-stibnite vein generation is often discreet and confined to one side of the vein with the lamination adhering to the other contact. Gold is commonly found in the laminations of the older quartz generation.
- Single-generation quartz veins in subvertical orientations, linking between the laminated, bedded veins (Figure 7, CSK044). These structures most likely developed under extensional stress contemporaneous with the time of mineralisation.
- East-dipping veins found on the western limb of the Cuffley Anticline, crosscutting the bedding at a high angle. These veins appear to be exploiting an earlier axial, spaced fabric including jointing and minor faulting developed at the time of anticline formation. The existence of these veins indicate that while the Lyre Fault has some post-mineralisation movement, it is not necessarily a hard boundary to mineralisation in this domain.
All veins have demonstrated the capability to host coarse, high-grade gold and varying amounts of massive stibnite. In general, antimony grades are of lesser importance within the Sub-KC deposit relative to other mined deposits at Costerfield, perhaps due to comparatively limited vein volumes which does not appear to influence gold prospectivity. “Rusty” gold after aurostibite is commonly observed, along with occasional veins containing native antimony metal (Figure 8) typically with small amounts of pyrrhotite. This assemblage indicates minor activity of a lower sulphur, relatively reduced ore fluid phase.
Drilling Results - Cuffley
23 growth and infill holes have been completed, totalling 3,255m of diamond drill core. This activity resulted in 18 new intercepts on the mineralised structure, the remaining five fault blanking as the bounds of the new domain was explored. Four drillholes intercepted mineralisation grading over 10g/t gold equivalent over mining width:
- 580.9g/t gold and 24% antimony over 0.61m (ETW 0.54m) in AD270
- Including 0.25m @ 1360g/t gold & 19.7% antimony (Figure 6)
- 168.9g/t gold and 33.5% antimony over 0.9m (ETW 0.78m) in AD265
- 60.1g/t gold and 15.2% antimony over 1.26m (ETW 1.17m) in AD292
- 124g/t gold and 48.6% antimony over 0.23m (ETW 0.22m) in AD275
An additional four holes graded over 2g/t gold equivalent over mining width.
Drilling Results – Sub KC
Four target-testing holes were drilled for 3705.32m, and ten parent / two wedge growth and infill holes were completed for 8168.28m.
Several ore-grade intercepts were made within the system, including:
- 28.2g/t gold and 0% antimony over 0.99m (ETW 0.82m) in CSK044
- 73.2g/t gold and 18.8% antimony over 0.19m (ETW 0.18m) in CSK043
- 192g/t gold and 0% antimony over 0.17m (ETW 0.07m) in CSK043
- 16.1g/t gold and 12.7% antimony over 0.37m (ETW 0.34m) in CSK048
The target testing holes explored the footwall of the Lyre Fault along strike north and south of the main Sub-KC block, testing for repetitions in zones modelled to have favourable structural setup. The two holes drilled approximately 400m north of the main block found the Lyre Fault plane to have stepped eastward in position, faulting out much of the inferred favourable east-dipping fold limb. These two holes intercepted moderate grades in the Adder Fault, located just into the wall from the collar point.
Conversely, the holes drilled approximately 300m south of the Sub-KC zone found an intact anticlinal position, without the presence of the expected Lyre Fault, which appears to be located further westward at this point. Both holes encountered veins with anomalous gold however no ore-grade intercepts were made.
Figure 2. Long Section of the Cuffley System with major vein target envelopes displayed, recent drill traces and > 6g/t AuEq new intercepts labelled. New significant intercepts not associated with a named structure are represented as triangular icons. Older significant drill intercepts are displayed as smaller, unlabelled icons. Previous mining on the Cuffley Lode with face assays and depleted areas area are also shown.
Figure 3. Long Section of the Sub-KC System 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. New significant intercepts not associated with a named structure are represented as triangular icons.
Figure 4. Plan Section of the Cuffley and Sub KC deposits with vein best fit traces displayed, recent drill traces and > 6g/t AuEq new intercepts labelled. Older significant drill intercepts are displayed as smaller, unlabelled icons. New significant intercepts not associated with a named structure are represented as triangular icons.
Figure 5. Cross section looking north at mine northing 4900N showing the Cuffley and Sub-KC systems (veins represented schematically), and > 6g/t AuEq new intercepts labelled. Older significant drill intercepts are displayed as smaller, unlabelled icons. New significant intercepts not associated with a named structure are represented as triangular icons.
Figure 6. Core tray photo of the high-grade Cuffley intercept in AD270. Note the very high gold interval of 1360g/t Au, and consistent high-grade antimony. Please refer to Appendix 1 for the relevant assay results relating to Figure 6.
Figure 7. Core tray photographs of the Sub-KC 405 Lode intercepts from drillholes CSK043 (bottom) and CSK044 (top). Intervals with grade above detection levels are labelled. Note the bedding-parallel nature of the major veins, due to reactivation of early laminated quartz structures acting as host structure, and the additional occurrence of high grade visible gold in very narrow veinlets (CSK044, 537m). Please refer to Appendix 1 for the relevant assay results relating to Figure 7.
Figure 8. Vein containing a significant volume of native antimony metal (metallic white) intercepted in CSK045W1 (538.15m). The vein also contained stibnite and pyrrhotite, and pyrite wallrock alteration can be seen in the image. Please refer to Appendix 1 for the relevant assay results relating to Figure 8.
Future Plans
The new grade pod at Cuffley has been integrated into the Costerfield mine plan and is scheduled to be mined. Considerable scope remains for further growth within the Sub KC domain with the structural information gained from the north and south target testing holes, however drilling will likely need to be undertaken from surface, or future development with improved intersection angles with the target areas.
This document has been authorised for release to the market by Nic Earner, Managing Director.
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 (refer to ASX announcement dated 14 July 2026 titled ‘Alkane Extends High Grade Gold Trend at Brunswick South’). 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 Cuffley and Sub KC drilling programs at Costerfield
| Drill Hole ID | From (m) | To (m) | Interval (m) | Estimated True Width (m) | Au (g/t) | Sb (%) | Gold-equiv. grade diluted to 1.8 m (g/t) | Interpreted Vein |
| AD265 | 78.31 | 79.21 | 0.90 | 0.78 | 168.9 | 33.5 | 107.4 | Cuffley |
| AD266 | 97.50 | 98.70 | 1.20 | 0.88 | 6.7 | 2.4 | 6.1 | Cuffley |
| AD270 | 75.70 | 76.31 | 0.61 | 0.54 | 580.9 | 24.0 | 192.0 | Cuffley |
| Including | 76.06 | 76.31 | 0.25 | 0.20 | 1360.0 | 19.7 | ||
| AD272 | 80.59 | 80.96 | 0.37 | 0.29 | 0.0 | 0.0 | 0.0 | Cuffley |
| AD273 | 89.53 | 89.69 | 0.16 | 0.13 | 4.2 | 1.2 | 0.5 | Cuffley |
| AD274 | 72.42 | 72.56 | 0.14 | 0.13 | 0.8 | 2.4 | 0.5 | Cuffley |
| AD275 | 76.11 | 76.34 | 0.23 | 0.22 | 124.0 | 48.6 | 28.8 | Cuffley |
| AD276 | 80.78 | 80.95 | 0.17 | 0.14 | 0.5 | 0.0 | 0.0 | Cuffley |
| AD277 | 80.65 | 81.03 | 0.38 | 0.33 | 17.8 | 0.9 | 3.6 | Cuffley |
| AD278 | 73.81 | 74.46 | 0.65 | 0.61 | 6.9 | 0.9 | 3.1 | Cuffley |
| AD283 | 82.52 | 83.02 | 0.50 | 0.41 | 0.1 | 0.1 | 0.1 | Cuffley |
| AD286 | 81.76 | 82.08 | 0.32 | 0.26 | 0.0 | 0.0 | 0.0 | Cuffley |
| AD290 | 105.50 | 105.62 | 0.12 | 0.07 | 38.5 | 19.1 | 3.5 | Cuffley |
| AD292 | 72.74 | 74.00 | 1.26 | 1.17 | 60.1 | 15.2 | 62.9 | Cuffley |
| AD293 | 95.81 | 96.07 | 0.26 | 0.18 | 0.0 | 0.0 | 0.0 | Cuffley |
| CSK043 | 503.40 | 503.66 | 0.26 | 0.23 | 0.1 | 0.2 | 0.1 | Sub KC 401 |
| CSK044 | 496.86 | 497.42 | 0.56 | 0.51 | 0.1 | 1.2 | 0.9 | Sub KC 401 |
| CSK048 | 522.80 | 523.17 | 0.37 | 0.34 | 16.1 | 12.7 | 8.8 | Sub KC 401 |
| CSK032 | 461.24 | 461.42 | 0.18 | 0.15 | 0.0 | 0.0 | 0.0 | Sub KC 402 |
| CSK042 | 533.22 | 533.44 | 0.22 | 0.20 | 0.1 | 0.0 | 0.0 | Sub KC 402 |
| CSK043 | 511.23 | 511.42 | 0.19 | 0.18 | 73.2 | 18.8 | 12.0 | Sub KC 402 |
| CSK044 | 504.42 | 505.27 | 0.85 | 0.84 | 1.6 | 0.1 | 0.9 | Sub KC 402 |
| CSK046 | 525.64 | 525.80 | 0.16 | 0.15 | 0.3 | 0.0 | 0.0 | Sub KC 402 |
| CSK048 | 531.03 | 531.23 | 0.20 | 0.19 | 10.6 | 26.2 | 7.6 | Sub KC 402 |
| CSK042 | 497.87 | 498.00 | 0.13 | 0.12 | 0.0 | 0.0 | 0.0 | Sub KC 405 |
| CSK043 | 491.10 | 491.21 | 0.11 | 0.10 | 3.2 | 0.0 | 0.2 | Sub KC 405 |
| CSK044 | 484.73 | 485.03 | 0.30 | 0.30 | 1.9 | 0.0 | 0.3 | Sub KC 405 |
| CSK048 | 508.43 | 508.56 | 0.13 | 0.12 | 22.9 | 11.3 | 3.4 | Sub KC 405 |
| CSK043 | 547.70 | 549.09 | 1.39 | 1.15 | 0.7 | 0.3 | 0.8 | Sub KC 410 |
| CSK044 | 536.70 | 537.69 | 0.99 | 0.82 | 28.2 | 0.0 | 12.9 | Sub KC 410 |
| CSK045 | 549.38 | 549.63 | 0.25 | 0.20 | 8.6 | 0.3 | 1.0 | Sub KC 410 |
| CSK045W1 | 543.82 | 547.08 | 3.26 | 2.70 | 1.0 | 0.7 | 2.7 | Sub KC 410 |
| CSK043 | 712.30 | 712.47 | 0.17 | 0.07 | 192.0 | 0.0 | 6.9 | Sub KC 420 |
| CSK045 | 670.90 | 671.90 | 1.00 | 0.40 | 0.2 | 0.0 | 0.1 | Sub KC 420 |
| CSK035 | 942.41 | 942.54 | 0.13 | 0.10 | 0.0 | 0.0 | 0.0 | Sub KC 425 |
| CSK040 | 667.34 | 668.03 | 0.69 | 0.40 | 0.1 | 0.0 | 0.0 | Sub KC 425 |
| CSK040W1 | 634.05 | 636.00 | 1.95 | 1.24 | 3.2 | 0.0 | 2.2 | Sub KC 425 |
| CSK042 | 624.48 | 624.71 | 0.23 | 0.12 | 52.3 | 0.0 | 3.6 | Sub KC 425 |
| AD269 | 106.20 | 108.38 | 2.18 | 0.78 | 2.8 | 1.0 | 2.3 | Cuffley Assoc. |
| AD269 | 111.51 | 111.81 | 0.30 | 0.12 | 1.8 | 11.4 | 2.0 | Cuffley Assoc. |
| AD277 | 77.92 | 78.03 | 0.11 | 0.09 | 5.9 | 14.7 | 2.1 | Cuffley Assoc. |
| AD277 | 79.23 | 79.67 | 0.44 | 0.36 | 2.3 | 1.9 | 1.4 | Cuffley Assoc. |
| AD279 | 78.92 | 79.13 | 0.21 | 0.20 | 30.3 | 21.7 | 8.9 | Cuffley Assoc. |
| AD279 | 80.62 | 81.06 | 0.44 | 0.20 | 99.1 | 0.1 | 11.0 | Cuffley Assoc. |
| AD279 | 85.66 | 86.46 | 0.80 | 0.59 | 4.4 | 0.2 | 1.6 | Cuffley Assoc. |
| AD281 | 119.20 | 119.54 | 0.34 | 0.25 | 40.6 | 3.6 | 6.8 | Cuffley Assoc. |
| AD291 | 170.25 | 170.70 | 0.45 | 0.10 | 15.9 | 5.7 | 1.7 | Cuffley Assoc. |
| AD292 | 79.65 | 79.79 | 0.14 | 0.11 | 22.1 | 0.0 | 1.3 | Cuffley Assoc. |
| AD294 | 165.19 | 165.30 | 0.11 | 0.08 | 7.0 | 8.0 | 1.1 | Cuffley Assoc. |
| AD294 | 177.26 | 177.58 | 0.32 | 0.17 | 4.7 | 19.9 | 4.9 | Cuffley Assoc. |
| CSK036 | 4.58 | 4.76 | 0.18 | 0.15 | 2.0 | 38.4 | 7.9 | Adder Ft Assoc. |
| CSK040 | 725.30 | 726.00 | 0.70 | 0.57 | 7.3 | 0.0 | 2.3 | Sub KC Assoc. |
| CSK043 | 487.70 | 487.83 | 0.13 | 0.11 | 6.7 | 28.6 | 4.7 | Sub KC Assoc. |
| CSK043 | 518.47 | 518.60 | 0.13 | 0.11 | 2.3 | 7.3 | 1.2 | Sub KC Assoc. |
| CSK044 | 533.36 | 533.56 | 0.20 | 0.20 | 89.9 | 0.0 | 9.9 | Sub KC Assoc. |
| CSK044 | 573.44 | 574.32 | 0.88 | 0.85 | 7.2 | 0.0 | 3.4 | Sub KC Assoc. |
| CSK045W1 | 538.15 | 538.48 | 0.33 | 0.32 | 25.4 | 5.7 | 7.1 | Sub KC Assoc. |
| CSK045W1 | 549.90 | 550.25 | 0.35 | 0.31 | 7.3 | 0.0 | 1.3 | Sub KC Assoc. |
| CSK045W1 | 554.05 | 554.63 | 0.58 | 0.55 | 3.5 | 0.0 | 1.1 | Sub KC Assoc. |
| CSK048 | 537.98 | 538.20 | 0.22 | 0.21 | 4.3 | 2.1 | 1.1 | Sub KC Assoc. |
| Notes | |||||
| 1. | The AuEq (gold equivalent) grade is calculated using the following formula: | ||||
| AuEq g per t = Au g per t + Sb% x | Sb price per 10kg × Sb processing recovery | ||||
| Au price per g × Au processing recovery | |||||
Prices and recoveries used: Au $/oz = 2,500 (Au US$/gram = 80.39); Sb $/t = 19,000 (Sb US$/10kg = 190); Au Recovery = 91% and; Sb Recovery = 92%. The Au recovery assumption and Sb recovery assumption is based on established processing and sales in respect of Costerfield. It is the Company’s opinion that all elements included in the metal equivalent calculation have a reasonable potential to be recovered and sold. | |||||
| 2. | The estimated true width of composites that are not interpreted to be connected to a major vein (identified as “Other” in the above table) have been calculated using a generic, conservative intercept angle (alpha angle) of 45 degrees. | ||||
| 3. | 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. | ||||
| 4. | Gold-equivalent grades for intervals with estimated true width >1.8m are not diluted. | ||||
Drill hole collar details from the Cuffley and Sub KC drilling at Costerfield covered in this release:
| Hole ID | Northing | Easting | Elevation | Depth | Azimuth | Dip | Date Completed |
| AD265 | 4806 | 15237 | 968 | 140.10 | 314.1 | -0.3 | 2/01/2026 |
| AD266 | 4806 | 15238 | 968 | 129.00 | 323.1 | -12.6 | 5/01/2026 |
| AD269 | 4806 | 15239 | 968 | 142.80 | 331.2 | -19.3 | 6/02/2026 |
| AD270 | 4801 | 15237 | 969 | 121.73 | 308.1 | 14.9 | 13/01/2026 |
| AD272 | 4802 | 15237 | 969 | 118.24 | 321.4 | 9.1 | 16/01/2026 |
| AD273 | 4806 | 15238 | 968 | 137.16 | 321.7 | -6.5 | 12/02/2026 |
| AD274 | 4799 | 15237 | 969 | 104.30 | 274.9 | 17.9 | 17/01/2026 |
| AD275 | 4800 | 15237 | 968 | 121.79 | 301.8 | -2.0 | 18/01/2026 |
| AD276 | 4806 | 15238 | 968 | 95.20 | 310.7 | -9.0 | 25/01/2026 |
| AD277 | 4800 | 15238 | 969 | 156.09 | 305.2 | 24.0 | 21/01/2026 |
| AD278 | 4801 | 15237 | 969 | 145.91 | 291.2 | 21.0 | 23/01/2026 |
| AD279 | 4805 | 15238 | 971 | 98.02 | 295.0 | 34.2 | 26/01/2026 |
| AD280 | 4806 | 15238 | 971 | 151.98 | 314.8 | 35.2 | 29/01/2026 |
| AD281 | 4806 | 15239 | 967 | 161.44 | 327.3 | -28.1 | 10/02/2026 |
| AD283 | 4806 | 15238 | 968 | 164.60 | 316.9 | -10.0 | 1/02/2026 |
| AD284 | 4806 | 15238 | 968 | 149.50 | 325.3 | -19.8 | 4/02/2026 |
| AD285 | 4806 | 15238 | 969 | 160.77 | 315.5 | 15.3 | 25/02/2026 |
| AD286 | 4806 | 15238 | 970 | 157.77 | 317.7 | 23.6 | 23/02/2026 |
| AD290 | 4806 | 15239 | 968 | 186.50 | 334.9 | -14.1 | 15/02/2026 |
| AD291 | 4806 | 15239 | 968 | 182.90 | 338.0 | -22.0 | 20/02/2026 |
| AD292 | 4806 | 15237 | 969 | 128.02 | 307.1 | 4.8 | 23/04/2026 |
| AD293 | 4806 | 15239 | 969 | 122.30 | 331.7 | 6.9 | 26/04/2026 |
| AD294 | 4806 | 15238 | 970 | 179.10 | 327.4 | 18.9 | 29/04/2026 |
| CSK032 | 5035 | 15301 | 913 | 899.50 | 274.9 | -71.5 | 27/02/2024 |
| CSK033 | 5035 | 15301 | 913 | 602.62 | 291.2 | -67.0 | 19/03/2024 |
| CSK034 | 4489 | 15463 | 1030 | 839.40 | 263.5 | -72.1 | 31/01/2025 |
| CSK034W1 | 4489 | 15463 | 1030 | 940.00 | 263.5 | -72.1 | 8/02/2025 |
| CSK035 | 4489 | 15463 | 1030 | 995.57 | 287.9 | -79.0 | 13/03/2025 |
| CSK036 | 5710 | 14939 | 945 | 872.50 | 133.8 | -33.8 | 10/03/2025 |
| CSK037 | 5710 | 14939 | 944 | 881.35 | 133.0 | -49.4 | 17/05/2025 |
| CSK040 | 4744 | 15474 | 865 | 732.57 | 290.0 | -55.6 | 9/06/2025 |
| CSK040W1 | 4744 | 15474 | 865 | 656.40 | 290.0 | -55.6 | 21/06/2025 |
| CSK042 | 4758 | 15461 | 865 | 667.12 | 302.4 | -50.1 | 22/06/2025 |
| CSK043 | 4757 | 15461 | 865 | 934.90 | 296.3 | -46.0 | 31/07/2025 |
| CSK044 | 4744 | 15474 | 865 | 668.01 | 280.3 | -48.0 | 21/09/2025 |
| CSK045 | 4756 | 15461 | 865 | 760.50 | 285.2 | -52.6 | 29/08/2025 |
| CSK045W1 | 4756 | 15461 | 865 | 600.00 | 285.2 | -52.6 | 7/09/2025 |
| CSK046 | 4757 | 15461 | 865 | 659.14 | 297.6 | -48.1 | 26/09/2025 |
| CSK048 | 4745 | 15474 | 866 | 752.50 | 298.9 | -44.0 | 20/10/2025 |
| CSK049 | 4745 | 15474 | 865 | 760.22 | 302.2 | -53.0 | 8/11/2025 |
Notes:
- Coordinate System: Costerfield Local Mine Grid
Appendix 2 - JORC Code, 2012 Edition – Table 1
Section 1 Sampling Techniques and Data
| Criteria | JORC Code explanation | Commentary |
| Sampling techniques |
| Sampling of Au and Sb mineralisation is from diamond drill core (HQ2 and NQ2). Due to the discrete mineralisation of the deposit, not all diamond drill core was required to be sampled. Sample intervals were determined and marked on the core by Alkane geologists using the following general rules:
Assays were completed by On Site in Bendigo, which is independent of Alkane and holds current ISO/IEC 17025 accreditation. The general methods were as follows:
|
| Drilling techniques |
| Deepcore Drilling is the drilling contractor utilised for the whole of this project within the reporting period. All diamond drilling was completed from underground and was completed using LM90 drill rigs utilising HQ2 and NQ2 diameters. Core orientation is performed each run, typically using an AXIS Champ Ori kit. |
| Drill sample recovery |
| Diamond drilling was routinely checked for core loss during both drilling and sampling. Core loss blocks were added by drillers and then checked by geologists or field technicians when the core was measured, and depth marks made. If problems were encountered with recovery and core block depths, the drill shift supervisor was advised and depth marking stopped until the issue was rectified. No relationship between grade and sample recovery has been established. Ore zones with poor recovery are redrilled until a representative sample is achieved. |
| Logging |
| All drill core was geologically logged as full core for the relevant rock quality designation, lithology, structural data, and sample intervals. Data capture was digital into the AcQuire software using validated codes. All drill core was photographed wet with high resolution photographs stored on the site’s server, which is routinely backed-up. |
| Sub-sampling techniques and sample preparation |
| Diamond core sampling intervals were standardised wherever possible and ranged from 5 cm to 1 m in length. Diamond drill core samples have been halved for sampling (whole core sampled if representative halving was not possible) guided by the orientation line or a cut line, with a consistent side of the cut core selected for assay to ensure unbiased sampling. The following sample preparation activities were undertaken by Alkane staff for both diamond drill core and underground channel samples:
|
| Quality of assay data and laboratory tests |
| The assaying protocols used at Costerfield have been developed to ensure expected levels of accuracy and precision are met for the style of mineralisation tested and utilised in the MRE. Samples were assayed for gold, antimony, arsenic, and iron using representative partial digest methodologies:
CRMs were either prepared using Costerfield material or were otherwise matrix matched to ensure a representative nature. At least one CRM was submitted with every batch of diamond core samples and typically at a rate of 1 standard per 25 samples. Up to six CRMs covering the expected ranges of gold and antimony mineralisation were in rotation during routine sampling. An assay result for a CRM was considered acceptable when the returned assay fell within three standard deviations of the CRM certification grade. Outside this range, the CRM assay was considered to have failed and all significant mineralised samples within the batch were re-assayed, where significant grades were defined as mineralised samples that may have a material-impact in future resource estimates. All actions or outcomes were recorded as comments in the QA/QC register. Alkane submitted uncrushed samples of basalt as blank material sourced from Geostats into assay sample lots, at a rate of 1 in every 30 samples, to test for contamination during sample preparation. The failure threshold for gold is 0.10 g/t, which was chosen since it represents ten times the detection limit of 0.01 g/t for AAS. The failure threshold for antimony is 0.05%, which was chosen for being five times the detection limit of 0.01% for AAS. Pulp duplicates were collected routinely at a rate of 1:22 by On Site and submitted with the primary sample for analysis. Precision was in line for the expected a variance in both gold and antimony. Umpire laboratory checks to three additional commercial assay laboratories are completed each year covering all new assays generated at the property. |
| Verification of sampling and assaying |
| Sampling intervals and numbering were validated by geologists prior to cutting, with pre-numbered sampling bags systematically used by the field technicians to ensure the correct sample was submitted under each ID. Internal validation of significant intercepts was completed by the exploration and senior geologists. Photographs, logging, sample weights and assay results were checked to ensure manual errors were eliminated. Key intercepts at Costerfield were also validated by the Resource Geologist and Competent Person during the interpretation and modelling or the Costerfield resource estimation. Assay and sampling data was automatically uploaded into the Acquire database system and QA/QC validated at the point of upload. Any issues were entered into a QA/QC register and resolved before data acceptance. Alkane staff conduct periodic visits to the On Site Laboratory in Bendigo and meet regularly with the Lab managers. In early 2023 a review was conducted by a third party (RSC Consulting Pty Ltd) to ensure the practices are appropriate. Nothing of major concern was found. Twinned holes are typically only drilled intentionally to get full recovery of an ore zone when the initial hole has core loss. There are inadvertent twinned intercepts within the database, particularly when the collar position is close to the mineralisation. Twinned intercepts provide consistent correlation of structure and mineralisation character however due to the short range grade variability common structurally controlled gold systems, may not have the same mineralisation tenor. No adjustment has been made to the assay data. |
| Location of data points |
| Drill hole collar locations have been determined by differential GPS or theodolite surveying methods, either by external surveyors or Alkane surveyors. A digital report is created and entered into the acQuire Database. Data entry accuracy is validated against a LiDAR topographic map and high-resolution satellite imagery. Downhole surveys are conducted using a digital Reflex EZ-TRAC tool, in both single-shot (30 m while drilling) and multi-shot mode (3 m spacing at end of hole) where required. All downhole survey data is digitally uploaded to the Reflex EZ-TRAC and automatically imported into the acQuire database. |
| Data spacing and distribution |
| The data spacing at Costerfield is variable. Initial drilling on any particular lode is sporadic but generally approximates 100 × 100 m spacing. This approach is considered appropriate for establishing a geological and grade continuity acceptable for an Inferred Mineral Resource. Following initial drilling and prior to mining, each lode is drilled to a spacing of approximately 40 m × 40 m. This is reduced in areas of structural complexity. This approach is considered appropriate for establishing a geological and grade continuity acceptable for an Indicated Mineral Resource. Where veins or mineralisation zones were sub-sampled, a full-length composite of variable thickness was used in the MRE. |
| Orientation of data in relation to geological structure |
| Drill holes at Costerfield are designed to ensure an Alpha angle greater than 30°, indicating that the orientation of the drill holes (and therefore samples) is appropriate for the structure. The drilling orientation compared to that of key mineralised structures is not considered to have introduced any sampling bias as the structures are currently interpreted. |
| Sample security |
| All drill core was delivered to the Brunswick site, which is securely gated, with video surveillance, and time stamped swipe card access. Drill core logging and sampling was completed in this secure facility. Sample bags containing sample material are placed in heavy duty plastic bags in which the sample submission sheet is also included. The plastic bags are sealed with a metal twisting wire or heavy-duty plastic cable ties. The bags are taken to a storage area that is under constant surveillance. A private courier collects samples daily and transports them directly to On Site in Bendigo, where they are accepted by laboratory personnel. Sample pulps from On Site are returned to Alkane for storage. The pulps are stored undercover, wrapped in plastic. |
| Audits or reviews |
| Internal reviews of the exploration process and procedures are completed by senior geologists. Routine monthly lab visits and reviews are conducted by site personnel and make up part of the QA/QC protocols. RSC Consulting Pty Ltd reviewed the sampling and QA/QC procedures and practices in early 2023. There were no major outcomes related to sampling techniques and data. |
Section 2 Reporting of Exploration Results
Criteria listed in the Section 1 also apply to this section.
| Criteria | JORC Code explanation | Commentary |
| Mineral tenement and land tenure status |
| Alkane manages the Costerfield Operation and holds a 100% interest in licences MIN4644, MIN5567, EL5432, EL5519, EL6842, EL6847, EL8320 and RL007485 which comprise the Property. There are no advanced projects in the immediate vicinity of the Property, and there are no other Augusta-style gold-antimony operations in production within the Costerfield district. Exploration on adjacent tenements (EL5546, EL006504, EL006280, EL5490, EL006001, EL6951, EL7352, EL007348, EL007366, EL007382, EL007498, EL007499 and EL007481. There are currently no known impediments to obtaining a licence to operate in the area. Alkane and its subsidiaries have been conducting both exploration activities and mining activities on the adjacent mining lease MIN4644 since 2006. |
| Exploration done by other parties |
| The Costerfield Property has been explored using modern methods since 1966. Previous exploration by Mandalay Resources (2009–2025), prior to its merger with Alkane, represents the most significant period of exploration having discovered Cuffley, Youle and Shephard lodes in that time. Exploration Results prior to this have either been validated by more result drilling or are not considered material to the project. |
| Geology |
| Narrow vein, gold-antimony and gold-only lodes are the targeted deposit styles at the Costerfield Property. Economic lode material consists of either a ‘typical’ gold-bearing quartz and carbonate with massive stibnite, or gold-only quartz and carbonate veining as seen in the Shepherd system. The mineralised shoots are understood to be structurally controlled, typically by the intersection of the lodes with major cross-cutting, gouge filled fault structures and shears. Notable west to northwest dipping thrust faults typically bound the mineralisation packages at the Costerfield Property but can become significantly mineralised themselves along the fault planes. Shallower and dominantly west dipping thrust faults, typically at very low angles or even parallel to bedding with a laminated quartz component, link between the larger order thrust faults. The link faults can also offset the vertical lode structures up to 50 m in an east–west sense. This structural framework leads to the subvertical, north–south extensional veining seen in the Augusta, Brunswick, True Blue and Shepherd systems, along with the moderately west-dipping fault reactivated deposit at Youle. |
| Drill hole Information |
| Refer to Appendix 1 for the summary of drill holes related to the Costerfield Property. |
| Data aggregation methods |
| Reported Exploration Results are intercept length weighted with no truncation of minimum and/or maximum grade applied. Exploration Results have been reported to represent the discrete structural shear or vein as determined by the resource geologist and Competent Persons. There is no cut-off grade for the inclusion of drill intercept if it is on structure. Aggregates are full-width of target structures/lodes and limited in true width to underground ore development widths of mining of 4.5 m and rely on structures being interpreted as parallel in orientation and representative in nature of the continuous vein. Gold is the dominant element of value and exploration results are reported as gold equivalent (AuEq) where: AuEq = Au (g/t) + 2.39 x Sb (%) And the AuEq factor of 2.39 is calculated:
|
| Relationship between mineralisation widths and intercept lengths |
| Exploration Results that have been included in the resource are reported as drill widths and true widths as determined by the drill hole orientation relative to the vein. Those results not yet included in the resource have been reported as drill widths and estimated true widths. |
| Diagrams |
| Appropriate cross sections, plan sections and long sections are included in the body of the report. |
| Balanced reporting |
| For veins that are interpreted though multiple drill holes all intercepts are tabulated in Appendix 1 and illustrated in the images within the body of the report. Any intercepts that are not interpreted at this stage, to be part of a wider structure are tabulated in Appendix 1 if the sampled grade is above 2g/t when diluted to 1.8m. |
| Other substantive exploration data |
| Additional exploration data used to assist and validate interpretations at Costerfield include the use of surface geological mapping and a 2D seismic line. Bulk density work using the immersion methodology was completed in 2021 on similar lode and waste material at the Costerfield deposit. A regression formula is used for the BD of lode material: Augusta, Cuffley, Brunswick Lodes: BD= ((1.3951*Sb%)+(100-(1.3951*Sb%)))/(((1.3951*Sb%)/4.56)+((100-(1.3951*Sb%))/2.74)) where the host rock BD is 2.74 g/cm3 Youle/Shepherd/True Blue:
There are no material occurrences of deleterious elements. |
| Further work |
| The Exploration Results reported in this document refer to areas of the Costerfield Property already in production as well as potential future production areas. Future exploration will be focused on advancing these areas through to an Indicated Resource, if drilling is successful. In addition, exploration will be conducted on the margin of currently operating areas to increase mine life where possible. |
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
Photos accompanying this announcement are available at:
https://www.globenewswire.com/NewsRoom/AttachmentNg/adb351a0-caf6-4777-bc9e-cb50336502b7
https://www.globenewswire.com/NewsRoom/AttachmentNg/1d81658e-65cf-4048-8608-4b95b4fedaaf
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