Aston Bay Identifies New Near-Surface Copper Targets Through Integrated 3D Modelling at the Epworth Copper-Silver Project, Nunavut, Canada

Additional ground staked; planning underway for additional 2026 surface work and positioning for anticipated 2027 drill program

TORONTO, ON / ACCESS Newswire / August 27, 2026 / Aston Bay Holdings Ltd. (TSXV:BAY)(OTCQB:ATBHF) ("Aston Bay" or the "Company") is pleased to announce results from geophysical modelling of its Epworth sediment-hosted copper ("Cu") - silver ("Ag") - zinc ("Zn") - cobalt ("Co") - gold ("Au") project ("Epworth" or the "Project") located 80 kilometres ("km") southeast of Kugluktuk in Nunavut, Canada.

Highlights

• New discovery: two independent 3D 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 3D Magnetic Vector Inversion (MVI) and resistivity inversion modelling, completed across 126 square km, 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% Cu, 217 g/t 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 pre-positioned for a 2027 drill program to test these high-priority targets.

• 18.7 square km of additional prospective ground staked, bringing the Epworth Property to 1040.7 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, CEO 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 de-risks 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 January 15, 2026, Aston Bay news release). Chalcocite boulders yield up to 61.2% 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% Cu, 27.4% Zn, 1,100 g/t Ag, 3.0 g/t gold ("Au") and 1700 ppm cobalt ("Co"). Several new showings from the 2025 mapping program (e.g., 29.2% 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 and Figure 1). The survey used 100-meter ("m") line spacing in the northern half of the claim block and 200m spacing in the southern half. The resulting 2.5D resistivity inversion models, plan maps, depth slices and sections of the electromagnetic and magnetic datasets formed the basis for geophysical interpretation and targeting.

Figure 1. Example of a helicopter with a probe slung for airborne MT (https://expertgeophysics.com/services/)

Unlocking New Copper Targets with Advanced 3D Modelling Technology

Aston Bay engaged Global Geologica to complete 3D Magnetic Vector Inversion (MVI) modelling of the magnetic data and 3D 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 (Figure 2). 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.

Figure 2. Cross section lines A-A' and B-B' within the area of new geophysical inversion modelling relative to the Aston Bay tenement and MobileMT survey area. Recently staked claims outlined in red.

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 3D 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 ~1.27 Ga Mackenzie dyke swarm (NNW with subordinate NE-trending set) and accentuate the basin architecture.

Several compelling exploration targets are evident in the new 3D dataset, with two representative section lines, A-A' and B-B' (Figures 3 through 6), presented herein.

The resulting MVI and resistivity inversion datasets 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 (<750 m below surface) (Figures 3 and 5). Integrating these datasets has generated several previously unrecognized near-surface exploration targets (Figures 4 and 6). 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.

Figure 3. Oblique view of EM resistivity isosurfaces overlaid on the MVI voxel model, highlighting the spatial association between conductive features (resistivity shells) and magnetic breaks (abrupt changes in the colour-shaded magnetic data, locally represented by dashed lines). East-West section A-A' looking north; see Figure 2 for line of section. No vertical exaggeration.

Figure 4. Oblique view of EM resistivity isosurfaces overlaid on the MVI voxel model, identifying exploration targets based on overlapping geophysical signatures. East-West section A-A' looking north; see Figure 2 for line of section. No vertical exaggeration.

Figure 5: Oblique slice through the integrated 3D geophysical models, illustrating the recurrence of a similar geophysical signature across several possible prospects as also seen in section A-A'. East-West section B-B' looking north; see Figure 2 for line of section. No vertical exaggeration.

Figure 6: Oblique slice through the integrated 3D geophysical models, identifying targets based on overlapping geophysical signatures. East-West section B-B' looking north; see Figure 2 for line of section. No vertical exaggeration.

Promising Signs for Large-Scale Copper Mineralization

Analysis of the integrated 3D resistivity and MVI models highlights a strong spatial association between deep-seated magnetic breaks and vertically and horizontally extensive linear conductive bodies (Line A-A', Figure 3 and Line B-B', Figure 5). 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 3D 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 3D 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 (Figure 2. The Epworth Property now comprises a total of 1040.7 square km.

Next Steps

• Work is underway 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 underway 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 pre-positioned over the winter for an anticipated 2027 drill program.

Qualified Person

Michael Dufresne, M.Sc., P.Geol., P.Geo., and Coleman Robertson, B.Sc., P.Geo., 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 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 (QAQC) 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 ores; and OREAS 24b, barren granodiorite.

Rock samples referenced in this news release were analyzed using ActLabs method "UT-6M," a 4-acid total digestion with ICP-OES/MS finish, yielding geochemical results for 48 elements. Samples with over-limit base metal results (>1%) were further analyzed using ActLabs method "8-4 Acid Total Digestion", a total digestion with ICP-OES finish, and lead samples >15% were further analyzed using ActLabs method "8-Peroxide ICP-OES," a sodium peroxide fusion with ICP finish. Samples with over-limit silver results (>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 50g fire assay with atomic absorption finish for gold, with over-limit results analyzed using method "1A3-50," a 50g fire assay with gravimetric finish. Select samples were analyzed using ActLabs method 1C-Exp, a gold-PGE 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 <500 km to the south. The property consists of 85 claims covering an area of approximately 140,700 ha (257,163 acres) over a trend approximately 94 km in strike length and 20 km in lateral extent.

Figure 7: Location of the Epworth Property, Nunavut, Canada.

Agreement

Aston Bay has entered into an agreement with Emerald Geological Services under which Aston Bay can earn an 80% 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

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.

FORWARD-LOOKING STATEMENTS

Statements made in this news release, including those regarding entering into the joint venture and each party's interest in the Project pursuant to the agreement in respect of the joint venture, management objectives, forecasts, estimates, expectations, or predictions of the future may constitute "forward-looking statement", which can be identified by the use of conditional or future tenses or by the use of such verbs as "believe", "expect", "may", "will", "should", "estimate", "anticipate", "project", "plan", and words of similar import, including variations thereof and negative forms. This press release contains forward-looking statements that reflect, as of the date of this press release, Aston Bay's expectations, estimates and projections about its operations, the mining industry and the economic environment in which it operates. Statements in this press release that are not supported by historical fact are forward-looking statements, meaning they involve risk, uncertainty and other factors that could cause actual results to differ materially from those expressed or implied by such forward-looking statements. Although Aston Bay believes that the assumptions inherent in the forward-looking statements are reasonable, undue reliance should not be placed on these statements, which apply only at the time of writing of this press release. Aston Bay disclaims any intention or obligation to update or revise any forward-looking statement, whether as a result of new information, future events or otherwise, except to the extent required by securities legislation.

Neither TSX Venture Exchange nor its regulation services provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release.

For more information contact:

Thomas Ullrich, Chief Executive Officer
thomas.ullrich@astonbayholdings.com
(416) 456-3516

Sofia Harquail, IR and Corporate Development
sofia.harquail@astonbayholdings.com
(647) 821-1337

SOURCE: Aston Bay Holdings Ltd.

View the original press release on ACCESS Newswire