Mr. Thomas Ullrich reports

ASTON BAY IDENTIFIES NEW NEAR-SURFACE COPPER TARGETS THROUGH INTEGRATED 3-D MODELLING AT THE EPWORTH COPPER-SILVER PROJECT, NUNAVUT, CANADA

Aston Bay Holdings Ltd. has released results from geophysical modelling of its Epworth sediment-hosted copper-(Cu)-silver-(Ag)-zinc-(Zn)-cobalt-(Co)-gold-(Au) project located 80 kilometres (km) southeast of Kugluktuk in Nunavut, Canada.

Highlights

• New discovery: Two independent 3-D geophysical inversions converge on a series of large, previously unrecognized near-surface targets across the highly prospective southern Epworth trend -- a strong validation signal in copper exploration.
• Advanced 3-D magnetic vector inversion (MVI) and resistivity inversion modelling, completed across 126 square kilometres, has mapped a complete basin-scale "plumbing system" for copper mineralization for the first time at Epworth.
• Deep-seated structural breaks identified by MVI align directly with strong conductive anomalies from the resistivity model -- the classic geophysical fingerprint of sulphide-bearing fluid pathways feeding copper mineralization.
• Several targets show conductive zones widening toward the surface, a textbook signature of stratigraphically controlled, sediment-hosted copper systems similar to the world-class Central African copper belt.
• These new targets sit directly on trend with 2025 surface discoveries, including new showings like Greenback (29.2 per cent Cu, 217 grams per tonne Ag) -- confirming the fertility of the system now mapped at depth.
• With overlapping geophysical evidence reducing false-positive risk, Aston Bay is fast-tracking ground geophysics, mapping and sampling this fall, with camp and fuel prepositioned for a 2027 drill program to test these high-priority targets.
• A total of 18.7 square kilometres of additional prospective ground staked, bringing the Epworth property to 1,040.7 square km in total area.

"It is very encouraging to see two independent geophysical inversions converge on the same overlapping signatures, giving us high confidence in a series of previously unrecognized, large near-surface targets across the southern portion of Epworth," stated Thomas Ullrich, chief executive officer of Aston Bay. "These results validate the basin-scale plumbing system we believe is responsible for the exceptional high-grade copper and silver mineralization already documented at surface, and point toward the kind of stratigraphically controlled, sediment-hosted system we have been targeting since acquiring the property. With ground geophysics, mapping and sampling planned for this fall to refine these targets, and camp and fuel logistics positioned over winter, we are well set up to move directly into drill testing in 2027. Epworth continues to demonstrate the scale and grade potential we look for, and this work meaningfully derisks our path to the drill bit."

Historic and recent work at Epworth has yielded high-grade copper and other base- and precious-metal mineralization at the surface (see Jan. 15, 2026, Aston Bay news release). Chalcocite boulders yield up to 61.2 per cent Cu with 5,600 grams per tonne (g/t) Ag in select rock grab samples from over 300 historical samples, with recent prospecting selective rock grab samples yielding up to 37.8 per cent Cu, 27.4 per cent Zn, 1,100 g/t Ag, 3.0 g/t gold (Au) and 1,700 parts per million cobalt (Co). Several new showings from the 2025 mapping program (that is, 29.2 per cent Cu with 217 g/t Ag in chalcocite veinlets at Greenback) are spatially associated with conductive anomalies in the southern portion of the claim block.

Most surface mineralization occurs in veins and local disseminations associated with faults, contacts, dikes and other zones of structural weakness. These are interpreted to represent productive fluid conduits for mobilizing metal-bearing fluids but are unlikely to generate significant tonnage of economic mineralization within the structures themselves, except under special circumstances. Intersection of this plumbing system with favourable, permeable stratigraphic horizons, however, could result in large-scale mineralization; this is similar in style to the sediment-hosted copper mineralization in deposits of the Central African copper belt and is the exploration target at Epworth.

MobileMT geophysical survey

Expert Geophysical Systems completed an 8,105 line km MobileMT MT geophysical survey spanning the entire Aston Bay claim block in 2024 (see June 5, 2025, Aston Bay news release). The survey used 100-metre (m) line spacing in the northern half of the claim block and 200 m spacing in the southern half. The resulting 2.5D resistivity inversion models, plan maps, depth slices, and sections of the electromagnetic and magnetic data sets formed the basis for geophysical interpretation and targeting.

Unlocking new copper targets with advanced 3-D modelling technology

Aston Bay engaged Global Geologica to complete 3-D magnetic vector inversion (MVI) modelling of the magnetic data and 3-D resistivity inversion modelling of the electromagnetic (EM) data acquired from the airborne MobileMT survey. The geophysical inversion modelling covers a subset area of 126 square km located in the southern portion of the claims. Integration of the magnetic susceptibility and electrical conductivity models has been completed, enabling interpretation of subsurface features in three dimensions, resulting in overlapping evidence for new target positions.

The resistivity inversion produced a single volume that reduces artifacts and directional bias associated with flight-line orientation that may be present in previous 2.5D inversion products. The resulting 3-D model provides an improved representation of the geometry and continuity of subsurface features, enhancing the delineation of faults, lithological contacts and other geological structures.

The magnetic inversion work was designed to minimize the effect of the approximately 1.27 Ga Mackenzie dike swarm (north-northwest- with subordinate northeast-trending set) and accentuate the basin architecture.

Several compelling exploration targets are evident in the new 3-D data set.

The resulting MVI and resistivity inversion data sets are independent and complementary; the magnetic data offer superior near-surface resolution and improved definition of the basin architecture, while the resistivity model highlights conductive features from near-surface to mid-depth (less than 750 m below surface). Integrating these data sets has generated several previously unrecognized near-surface exploration targets. Importantly, combining magnetic and conductivity interpretations reduces the likelihood of false-positive anomalies associated with conductive water bodies, providing a more robust framework for exploration targeting and drill planning.

Promising signs for large-scale copper mineralization

Analysis of the integrated 3-D resistivity and MVI models highlights a strong spatial association between deep-seated magnetic breaks and vertically and horizontally extensive linear conductive bodies. The subvertical breaks in the magnetic inversion are interpreted to represent major structures which have the potential to be fluid conduits for copper mineralization, while the coincident highly conductive anomalies may reflect the presence of sulphide-bearing material in the feeder structure.

The new 3-D models have revealed several unrecognized exploration targets near the surface, based on the following observations:

• Deep plumbing systems: Defined major breaks in the magnetic data that are interpreted to be the plumbing systems or pathways for mineral-rich fluids.
• Sulphide signatures: Alongside these features, the 3-D models from the electrical data show strongly conductive zones, which may indicate the presence of sulphide minerals (which commonly accompany copper).
• Favourable geometry: Some of these conductive zones widen as they get closer to the surface. This is a typical fingerprint for stratigraphically controlled copper deposits, suggesting mineral-rich fluids travelled up the faults and percolated through favourable permeable rock layers above.

With multiple targets showing this same promising geophysical signature, several new areas of interest across the southern portion of the project have been identified across multiple additional cross sections.

New staking

With the highly prospective anomalies trending off the property, 18.7 square km of new ground has been staked.

Next steps

• Work is under way to integrate these new targets with existing spatially coincident surface sampling results and newly acquired remote sensing data, with results expected within two weeks.
• Planning is under way for ground geophysical, structural, and geological mapping and sampling programs across the most prospective sections in September to ground-truth and refine drill targeting.
• Applications for drill and camp permit modifications have been initiated for definitive drill pad and camp locations, with fuel and camp supplies prepositioned over the winter for an anticipated 2027 drill program.

Qualified person

Michael Dufresne, MSc, PGeol, PGeo, and Coleman Robertson, BSc, PGeo, are non-independent qualified persons as defined by National Instrument 43-101 and have reviewed and approved the scientific and technical information in this press release.

QA/QC (quality assurance/quality control) protocols

Grab samples at the Epworth property were collected, documented and photographed in the field by Emerald Geological Services (EGS) personnel, then placed in sealed bags and periodically sent out by float plane from the camp to a secure location in Yellowknife. Subsequently, the sample bags, sealed with security tags, were shipped by transport to Activation Laboratories (ActLabs) in Thunder Bay, which is an ISO/IEC 17025 accredited laboratory. Grab sample collection is subject to EGS's internal quality assurance/quality control (QA/QC) protocols, which include the insertion of certified reference material (CRM) into each batch of samples submitted. These CRMs consisted of OREAS 166, a high-grade sedimentary copper standard; OREAS 920b, a blend of barren slate and mine waste rock; OREAS 230, a low-grade gold standard; OREAS 24d, barren basalt; OREAS 135b, a blend of black slate and Zn-Pb-Ag (zinc-lead-silver) ores; and OREAS 24b, barren granodiorite.

Rock samples referenced in this news release were analyzed using ActLabs method UT-6M, a four-acid total digestion with ICP-OES/MS finish, yielding geochemical results for 48 elements. Samples with overlimit base metal results (greater than 1 per cent) were further analyzed using ActLabs method "8-4 Acid Total Digestion," a total digestion with ICP-OES finish, and lead samples greater than 15 per cent were further analyzed using ActLabs method "8-Peroxide ICP-OES," a sodium peroxide fusion with ICP finish. Samples with overlimit silver results (greater than 100 ppm) were further analyzed using ActLabs method "8-Ag," a gravimetric fire assay. Most samples were also analyzed using ActLabs methods "1A2-50," a 50 g fire assay with atomic absorption finish for gold, with overlimit results analyzed using method "1A3-50," a 50 g fire assay with gravimetric finish. Select samples were analyzed using ActLabs method 1C-Exp, a gold-platinum group element fire assay with ICP-MS finish.

About the Epworth property

The Epworth property is located approximately 80 km southeast of the village of Kugluktuk (formerly Coppermine) in the Kitikmeot region of Nunavut, Canada. The property is approximately 70 km from tidewater to the north. Logistical access is provided by float plane and helicopter from Kugluktuk and the city of Yellowknife less than 500 km to the south. The property consists of 85 claims covering an area of approximately 140,700 hectares (257,163 acres) over a trend approximately 94 km in strike length and 20 km in lateral extent.

Agreement

Aston Bay has entered into an agreement with Emerald Geological Services under which Aston Bay can earn an 80-per-cent undivided interest in the property by spending a minimum of $3-million in qualifying exploration expenditures over a four-year period. See Aston Bay April 24, 2024, news release for details of the agreement and Aston Bay June 4, 2025, news release for additional property details.

About Aston Bay Holdings Ltd.

Aston Bay is a publicly traded mineral exploration company exploring for high-grade critical and precious metal deposits in North America. The company is exploring the Storm copper property and Epworth Cu-Ag-Zn-Co property in Nunavut.

We seek Safe Harbor.