Guardian Metal Resources PLC Announces Pilot Mountain - Porphyry South Results

Rhea-AI Summary

Guardian Metal Resources (OTCQX:GMTLF) announced final inversion results from a 2025 3D induced-polarisation (3DIP) survey at the Pilot Mountain Project, Nevada, expanding coverage >1 km south across the Porphyry South zone.

The integrated 2022–2025 data show a ~1 km2 chargeable anomaly (>25 ms at 200 m depth) forming a chargeability–resistivity “donut” halo around a magnetic high. The inner margin of the chargeable halo aligns with highest surface copper results and follows a 2024 drill hole (PM24‑002a) that intercepted 385.1 m of porphyry-style mineralisation with molybdenum up to 1,170 ppm. Company to prioritise drilling inner pyrite shell targets into 2026.

Positive

• 3DIP defines ~1 km2 chargeable anomaly (>25 ms at 200 m depth)
• PM24‑002a intercepted 385.1 m porphyry-style mineralisation
• Rock chips include up to 2.05% Cu and molybdenum up to 1,170 ppm

Negative

• Inner copper‑enriched shell target has not been drill tested
• No mineral resource or reserve reported for Porphyry South to date

Geophysical Survey Highlights Significant Porphyry Target

LONDON, UK / ACCESS Newswire / November 19, 2025 / Guardian Metal Resources plc (LON:GMET)(OTCQX:GMTLF), a strategic mineral exploration and development company, is pleased to announce the results of a three-dimensional induced polarisation ("IP" or "3DIP") geophysical survey completed as part of the Company's ongoing porphyry copper-molybdenum (Cu-Mo) focused exploration campaign at its Pilot Mountain tungsten project ("Pilot Mountain" or the "Project") located in Nevada, USA.

Final inversion results from the survey have now been received. These have been integrated with previous IP and magnetic geophysical survey results as well as geological and geochemical findings from the Company's field exploration completed to date across the Porphyry South zone.

TECHNICAL SUMMARY

•	IP survey completed over the Porphyry South zone (Figure 1 & 2). The 2025 survey extended coverage >1 km south from the 2022 survey area following the identification of more extensive porphyry-style alteration and mineralisation than previously recognised.
•	A strong chargeable anomaly forms a well-defined halo around the Porphyry South magnetic high feature. Strong chargeability zones often coincide with an abundance of sulphide mineralisation. This chargeable halo looks to strongly represent the porphyry system's "pyrite shell" (or quartz-sericite-pyrite halo). Pyrite shells typically represent the outer extents of mineralisation within a Cu-Mo porphyry deposit. In porphyry deposits the most enriched part of the system is typically immediately between the pyrite shell and the inner potassic core.
•	Importantly, the inner margin of the modelled chargeable halo aligns with highest copper results obtained from the surface rock-chip sampling completed to date. This could be indicative of a copper enriched shell located between the inner high temperature potassic core and the pyrite shell. This feature has not been drill tested and constitutes a compelling future drilling target.
•	The geophysical results have greatly improved the Company's confidence in the Porphyry South zone by revealing a clear zonation pattern that is characteristic of many significant global porphyry systems. Future drilling will prioritise testing the inner portions of the interpreted pyrite shell.
•	The Company is also hosting third-party site visits focused specifically on the porphyry potential at Porphyry South and across the broader Project area.
•	A comprehensive Pilot Mountain operational update is being prepared by the Company and will be released in due course.

Oliver Friesen, CEO of Guardian Metal, commented:

"Although our primary focus remains firmly on advancing Pilot Mountain's tungsten deposits at Desert Scheelite and Garnet, the latest work on Porphyry South continues to highlight the broader potential of the Project area. The new results point to a much larger and more coherent porphyry system than previously understood, with features that are increasingly consistent with a fertile mineralised porphyry centre.

"These findings reinforce our belief that Pilot Mountain may host meaningful upside beyond the extremely important tungsten development pathway that is progressing at pace, and we will continue to advance the porphyry opportunity in a measured and cost-effective way into 2026."

BACKGROUND

The Company drilled hole PM24-002a in 2024 to test the Porphyry South magnetic anomaly. PM24-002a intercepted 385.1 m of porphyry-style mineralisation and alteration from immediately beneath overburden at 22m to a downhole depth of 407.1m end of hole (EOH). The intercept included multiple intervals of potassic alteration and several intervals containing >300 ppm and up to 1,170 ppm molybdenum^1,2. Given the success of the inaugural drillhole, the Company subsequently retained a porphyry-system specialist, Dr Lawrence Carter, to evaluate Porphyry South and to guide follow-up exploration activities.

Field mapping at Porphyry South through 2024 and 2025 has delineated a sizeable zone of outcropping silicic and quartz-sericite-pyrite ("QSP") alteration, copper showings, stockwork quartz veins and gossanous breccias in metasediments intruded by a quartz monzonite. Through geochemical fingerprinting completed by the Company, the magmatic system was confirmed as "fertile" for porphyry Cu-Mo mineralisation³. Previously reported rock chip sampling from outcrop shows highly elevated copper and molybdenum concentrations across the majority of Porphyry South (Figure 1). ⁴ The circa 1 km long "Breccia Ridge Zone" which is defined by gossanous and cuprite-malachite-tenorite mineralised breccias within Porphyry South is also highlighted by 15 rock chip samples from along the ridge containing up to 2.05% copper (Figure 1).

SURVEY FINDINGS

Based on the above noted positive findings, the Company expanded the 2022 3DIP survey grid >1 km to the south to more wholly-map the subsurface resistivity (a proxy for silicification) and chargeability (a proxy for sulphide mineralisation) of Porphyry South to assist with future drill targeting. The 2025 IP grid consisted of 13 north-south oriented survey lines, spaced at 200 m, that varied in length from 1,200 m to 1,700 m. The data was integrated with the IP data acquired in 2022.

The latest geophysical data shows an extensive chargeable anomaly (~1 km² area >25 ms, at 200 m depth slice) in the southern part of Pilot Mountain, which is partly coincident and also appears below an extensive resistive zone (Figure 1 & 2). Both these resistive and chargeable zones form a "donut" shaped halo around the Porphyry South magnetic high, which PM24-02a found to represent a potassically altered quartz monzonite intrusion with porphyry-style, molybdenite mineralisation, and is interpreted to represent a lower-grade, high temperature core of the porphyry system.

The Company interprets the resistive zone to represent silicic alteration of the metasediments since it coincides with outcropping areas of intense quartz stockwork veining. The extensive chargeable halo is interpreted to represent a "pyrite shell" to the porphyry system. Pyrite shells typically represent the outer extents of hypogene mineralisation in porphyry deposits. The inner part of the chargeable halo coincides with copper and molybdenum rich zones from previously reported rock chip sampling surveys.⁴

Typically, in porphyry deposits the most copper enriched zones are found immediately between the pyrite shell and the potassic core (which sits within the pyrite shell).

Significantly, these newly delineated chargeable and resistive geophysical features are consistent in nature to, but notably larger than, the Porphyry Central zone identified by the Company's previous 2022 IP survey (Figure 1). The single historic (circa 1970s) shallow drill hole completed by the Duval Corporation within Porphyry Central, hole DH-1-70, reported quartz-chalcopyrite-molybdenite veins in QSP altered quartz monzonite (i.e. copper-molybdenum porphyry-style mineralisation).

The integrated (2022 and 2025) IP survey results are now being used to finalise future drill targets for porphyry style copper-molybdenum mineralisation at Porphyry South and Porphyry Central.

Figure 1.Map of the Pilot Mountain Project showing the integrated 2022 and 2025 3DIP surveys (200 m depth slice) across the Porphyry South and Porphyry Central zones. Outline of the Porphyry South magnetic high shown in light pink, and surface rock chip sample copper (Cu) concentrations as red dots.

Figure 2.IP inversion model view looking downwards east-southeast at Porphyry South and Porphyry Central, showing PM24-002a drill collar and trace, dipoles from 3DIP surveys, >20 ms chargeable zones and >0.02 and >0.04 magnetic susceptibility highs (scale: black drill hole trace is ~400m).

COMPETENT PERSON STATEMENT

The technical information contained in this disclosure has been read and approved by Mr Nick O'Reilly (MSc, DIC, MIMMM QMR, MAusIMM, FGS), who is a qualified geologist and acts as the Competent Person under the AIM Rules - Note for Mining and Oil & Gas Companies. Mr O'Reilly is a Principal consultant working for Mining Analyst Consulting Ltd which has been retained by Guardian Metal Resources plc to provide technical support.

References

1	https://www.londonstockexchange.com/news-article/GMET/pilot-mountain-significant-porphyry-update/16589687
2	https://www.londonstockexchange.com/news-article/GMET/pilot-mountain-nevada-significant-drill-results/16700934
3	https://www.londonstockexchange.com/news-article/GMET/geochemical-results-confirm-porphyry-cu-fertility/16758532
4	https://www.londonstockexchange.com/news-article/GMET/pilot-mountain-porphyry-copper-results/17162830

This announcement contains inside information for the purposes of Article 7 of EU Regulation 596/2014 (which forms part of domestic UK law pursuant to the European Union (Withdrawal) Act 2018).

Forward Looking Statements

This announcement contains forward-looking statements relating to expected or anticipated future events and anticipated results that are forward-looking in nature and, as a result, are subject to certain risks and uncertainties, such as general economic, market and business conditions, competition for qualified staff, the regulatory process and actions, technical issues, new legislation, uncertainties resulting from potential delays or changes in plans, uncertainties resulting from working in a new political jurisdiction, uncertainties regarding the results of exploration, uncertainties regarding the timing and granting of prospecting rights, uncertainties regarding the timing and granting of regulatory and other third party consents and approvals, uncertainties regarding the Company's or any third party's ability to execute and implement future plans, and the occurrence of unexpected events.

Actual results achieved may vary from the information provided herein as a result of numerous known and unknown risks and uncertainties and other factors.

For further information visit www.guardianmetalresources.com or contact the following:

Guardian Metal Resources plc Oliver Friesen (CEO)	Tel: +44 (0) 20 7583 8304
Cairn Financial Advisers LLP (Nominated Adviser) Sandy Jamieson/Jo Turner/Louise O'Driscoll	Tel: +44 (0) 20 7213 0880
Tamesis Partners LLP (Lead Broker) Charlie Bendon/ Richard Greenfield	Tel: +44 (0) 20 3882 2868
Tavistock (Financial PR) Emily Moss/Josephine Clerkin	Tel: +44 (0) 7920 3150/ +44 (0) 7788 554035 guardianmetal@tavistock.co.uk

About Guardian Metal Resources

Guardian Metal Resources PLC (LON: GMET, OTCQX: GMTLF) is a strategic mineral exploration and development company driving the revival of U.S. tungsten production and strengthening America's independence in defense metals. The Company is advancing two co-flagship tungsten projects, Pilot Mountain, one of the largest undeveloped tungsten deposits in the U.S. and Tempiute, formerly America's largest producing tungsten operation, both located in Nevada, one of the top-rated mining jurisdictions in the U.S.

In July 2025, Golden Metal Resources (USA) LLC, a wholly-owned subsidiary of Guardian Metal, was awarded US$6.2M from the U.S. Department of War under Title III of the Defense Production Act of 1950 to support the rapid advancement and pre-feasibility study for the Pilot Mountain tungsten Project. Guardian Metal Resources joined both the Defense Industrial Base Consortium and the Cornerstone Program. The Company has also announced plans to pursue a U.S. listing in the first half of 2026.

Tungsten is a strategic mineral essential to the defense, energy transition, technology, and industrial sectors. Against the backdrop of evolving geopolitical dynamics and Chinese export restrictions on tungsten, Guardian is positioned to play the leading role in rebuilding a reliable domestic supply chain for this critical metal.

This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom. Terms and conditions relating to the use and distribution of this information may apply. For further information, please contact rns@lseg.com or visit www.rns.com.

SOURCE: Guardian Metal Resources PLC

View the original press release on ACCESS Newswire

FAQ

What did Guardian Metal Resources announce about Pilot Mountain on November 19, 2025 (GMTLF)?

Guardian reported final 2025 3DIP inversion results showing a ~1 km2 chargeable anomaly and zonation consistent with porphyry Cu‑Mo mineralisation.

How does the 3DIP chargeable anomaly relate to previous drilling at Pilot Mountain (GMTLF)?

The anomaly forms a halo around a magnetic high and aligns with PM24‑002a, which intercepted 385.1 m of porphyry‑style mineralisation.

What key drill and geochemical metrics did Guardian report for Porphyry South (GMTLF)?

Reported metrics include PM24‑002a intercept of 385.1 m and rock chips up to 2.05% Cu and 1,170 ppm Mo.

Will Guardian Metal Resources drill the new porphyry targets at Pilot Mountain (GMTLF)?

The company said future drilling will prioritise testing the inner portions of the interpreted pyrite shell, targeting the copper‑rich zone into 2026.

What is the significance of the resistive and chargeable 'donut' feature at Porphyry South (GMTLF)?

The resistive zone likely marks silicic alteration while the chargeable halo is interpreted as a pyrite shell that typically bounds porphyry mineralisation.