Core Silver Discovers New Copper Porphyry Veins at Laverdiere

Rhea-AI Summary

Core Silver (CCOOF) announced discovery of a new copper-bearing porphyry vein system at Copper Creek, part of the Laverdiere project in the Blue Property, Atlin Mining District, BC (October 20, 2025).

Key highlights include surface assays up to 1.35% Cu with 9.1 g/t Ag, and 0.63% Cu with 17 g/t Ag and 355 ppm Mo. The company says Cu-Mo-Ag mineralization is now confirmed across a 4.5-kilometre footprint and remains open for expansion; the new copper porphyry lies ~2.6 km south of the Valley Fault Zone. Additional 2025 exploration results, including drilling, will be released when available.

Positive

• Assay peak of 1.35% Cu with 9.1 g/t Ag
• Assay of 0.63% Cu with 17 g/t Ag and 355 ppm Mo
• Mineralized footprint confirmed across 4.5 kilometres
• New porphyry discovery located ~2.6 km south of Valley Fault Zone
• Multi-phase hydrothermal system evidenced by porphyry and epithermal veins

Negative

• None.

DISCOVERY EXPANDS MINERALIZED FOOTPRINT TO OVER 4.5 KILOMETRES - WIDESPREAD & HIGH-GRADE COPPER-SILVER-MOLYBDENUM ASSAYS HIGHLIGHT DISTRICT-SCALE PORPHYRY POTENTIAL AT THE BLUE PROPERTY

VANCOUVER, BC / ACCESS Newswire / October 20, 2025 / Core Silver Corp. ("Core Silver" or the "Company") (CSE:CC)(FSE:8ZR)(OTCQB:CCOOF) is pleased to confirm the discovery of a new copper-bearing porphyry vein system at Copper Creek, part of the Laverdiere Copper Project (the "Project"), located on the eastern side of the Company's Blue Property (the "Property") in the Atlin Mining District of northwestern British Columbia.

HIGHLIGHTS

• In 2025, a new copper porphyry vein system was discovered along the lower section of Copper Creek, approximately 2.6 kilometres south of the Valley Fault Zone (Figure 1).

• Surface sample assays returned up to 1.35% Cu with 9.1 g/t Ag, and 0.63% Cu with 17 g/t Ag and 355 ppm Mo, with multiple additional samples yielding anomalous Cu-Mo-Ag values (Figure 2a/b).

• Steeply dipping malachite-chalcopyrite-bearing veins and fractures at Copper Creek are locally cross-cut by epithermal-style quartz-carbonate veining, indicating the presence of a multi-phase, robust hydrothermal system.

• Similar vein relationships are observed 1.8 kilometres west at Upper Copper Creek, where more intense epithermal stockwork veining has been sampled (assays pending) as well as along the Valley Fault.

• With this discovery, Cu-Mo-Ag mineralization is now confirmed across 4.5 kilometres at Laverdiere, extending from the Main Copper Skarn Zone (North Adit) to Copper Creek, and remains open for expansion in all directions.

• Additional results from the 2025 exploration program, including drilling, will be released as they become available.

Core Silver's President & CEO, Nick Rodway, commented:

"The discovery of a new copper porphyry vein system at Copper Creek marks an important step forward in demonstrating the true scale of the Laverdiere system. It is only our second drill season at Laverdiere, and we are seeing strong copper, molybdenum, and silver mineralization over 4.5-kilometres - a footprint that is rarely seen at this scale, during this stage of exploration in British Columbia. These strong surface results, combined with ongoing deep drilling at the Valley Zone, reinforce our view that the Blue Property hosts a district-scale copper-molybdenum-silver system capable of generating significant long-term value."

Figure 1: Plan view map highlighting Cu % in rocks collected from a newly discovered 200-metre-long trend of porphyry veining at Lower Copper Creek; overlain on CVG Magnetics (Geotech, 2021).

ABOUT THE COPPER CREEK DISCOVERY

In 2025, early prospecting at the Laverdiere Copper Project led to the discovery of a new copper-bearing porphyry-style vein and fracture system along the lower section of Copper Creek, located approximately 2.6 kilometers south of the 2025 drilling area situated along the Valley Fault Zone (Figure 1). Samples collected from this vein system early in the 2025 season returned 0.63% Cu with 17 g/t Ag and 355 ppm Mo, which warranted detailed mapping and systematic sampling of the area - including Upper Copper Creek. Structural mapping in early July delineated the mineralized vein and fracture system for just over 200 metres of strike length and ten (10) additional samples were collected from a combination of steeply dipping copper-bearing porphyry veins and exposed fracture/fault surfaces, as well as a cross-cutting felsic dyke and late, rusty epithermal-style quartz-carbonate veins. Chalcopyrite-malachite-bearing porphyry veins and fractures sampled during this time returned significant grades including values of up to 1.35% Cu and 9.1 g/t Ag, with several additional samples yielding anomalous Cu-Mo-Ag concentrations (Figures 2a/b).

Comparable relationships between porphyry and epithermal veining have also been observed 1.8 kilometres west at Upper Copper Creek-where more intense epithermal stockwork veining has been sampled (assays pending) - and along the Valley Fault Zone. With this latest discovery, the Cu-Mo-Ag footprint has been confirmed for over approximately 4.5 kilometres, extending from the Main Copper Skarn Zone (North Adit) to Copper Creek. Cu-Mo-Ag porphyry mineralization at the Laverdiere Copper Project is concentrated in fault splays and areas of increased structural complexity and hydrothermal alteration associated with the Llewellyn Fault Zone (LFZ). Currently, this district-scale target remains open for expansion in all directions.

Figure 2a: Photos of porphyry-epithermal veins along the Lower Copper Creek trend.

Figure 2b: Photos of porphyry-style veins and copper-bearing fractures and fault surfaces along the Lower Copper Creek trend.

ABOUT THE LAVERDIERE COPPER PROJECT

The Laverdiere Copper Project is a low-elevation, drill-permitted, early-stage high-grade Cu-Mo-Ag-Au porphyry-skarn Target. The Project has been sporadically explored since the early 1900s, without ever having received a significant exploration program. Adits driven into the Laverdiere area in the early 1900s reportedly returned up to 27m grading 1.20% Cu. The Llewellyn Fault Zone, a regional and strongly metal-endowed fault, cuts through the Laverdiere Copper Project for 14 km of strike length and marks the contact between the Yukon-Tanana and Stikine Terranes in the Project area. Currently only 1km of the total strike length of this economically important fault zone has been explored. Diamond drilling completed 125m north of the French Adit in 1974 reportedly returned 175m of 0.27% Cu, including 6m of 1.60% Cu and 7.8m of 1.60% Cu. Core Silver's inaugural diamond drilling campaign at the Laverdiere Copper Project in 2022 returned up to 48.5m of 0.90% Cu, 6g/t Ag, and 0.11g/t Ag from 31.46m depth in drill hole LAV22-001 (French Adit), 223m of 0.11% Cu, 2g/t Ag, and 0.006% Mo from 15m depth in LAV22-002 (French Adit), and 107.38m of 0.11% Cu, 0.023% Mo, 0.9g/t Au, and 0.02g/t Au from 144.62m depth in hole LAV22-006 (North Adit). The entirety of the 2022 Laverdiere Program results are summarized in the news release dated March 29^th, 2023.

Drilled and mapped high-grade copper-bearing skarn mineralization at Laverdiere is coincident with embayments in the contact zones of the expansive Cretaceous intrusion on the west side of Hoboe Creek. A large unexplored embayment in the intrusion is mapped 8km to the south of the to-date explored zone at Laverdiere and is in contact with Boundary Range metamorphic rocks at this location. Apophyses of the larger granodiorite intrusion are also mapped in contact with limestone and marbles amenable to massive sulphide skarn mineralization approximately 7km to the southwest of the known zones of high-grade porphyry-skarn mineralization.

At Laverdiere, an extensive Cretaceous granodiorite intrusion hosts widespread Cu-Mo-Ag±Au porphyry mineralization. The intrusion is associated with a very high-grade Fe-Cu-Au-Ag massive sulphide skarn occurrence (the "Main Zone") that is exposed at surface along the western flank of the prolific Llewellyn Fault Zone (LFZ) at the porphyry-marble contact. The Main Zone was drill-tested in 2022 and returned significant copper grades over extensive widths including: 267.05m of 0.17% Cu, 1g/t Ag, 0.04g/t Au from surface including 48.54m of 0.90% Cu, 6g/t Ag, 0.11g/t Au from 31.46m depth.

In 2024, high-grade porphyry Cu-Mo-Ag±Au mineralization at the newly defined Valley Zone, located 2.2km southwest of the Main Zone, was structurally mapped and sampled. At the Valley Zone, a series of sheeted mineralized porphyry veins and fractures hosted in altered granodiorite have been mapped and sampled over a 1-kilometer east-west trend following the Valley Fault that historically returned up to 3.24% Cu (with 82g/t Ag, 0.56g/t Au and 0.053% Mo) and 0.32% Mo (with 1.03% Cu, 4g/t Ag) in 2022. In 2024, a 20cm thick east-west striking quartz vein grading 0.83% Cu, 47g/t Ag, 0.44g/t Au and 0.007% Mo was discovered on the opposite side of the Valley Fault.

References
¹White, W.H. (1969): Geology and economic prospects of the Laverdiere property
² Fustos, A. (1974). Report on the Results of the 1973 Exploration Programme on the Loon Group. BC Ministry of Energy, Mines and Petroleum Resources, Assessment Report 4996

SAMPLING, PREPARATION & QA/QC

All 2025 rock and drill core samples are transported by helicopter at the end of each field day to the core logging facility in Atlin, BC for processing. Field samples were chosen to capture homogenous lithology, alteration, mineralization, and veining. All rock and drill core samples are submitted to Bureau Veritas (BV) Labs in Whitehorse, YT. Each sample is crushed to 70% passing 2mm, then pulverized to 85% passing 200-micron mesh. All samples then undergo a 4-Acid digestion with an ICP-MS finish for a 59-element ultra trace package (Method Code MA-250), as well as fire assay by Pb collection with ICP-ES finish for Au, Pt, and Pd (Method code FA-330). Samples that hit upper detection limits for elements of interest on the primary multi-element method are further analyzed via a secondary 4-Acid digest with an ICP-OES finish (Method Code MA-370). Extremely high-grade Pb samples were analyzed via a tertiary overlimit method, GC-817.

NI 43-101 DISCLOSURE & DATA VERIFICATION

Nicholas Rodway, P.Geo, (Licence# 46541) (Permit to Practice# 100359) is CEO and Director of the Company, and qualified person as defined by National Instrument 43-101- Standards of Disclosure for Mineral Projects. Mr. Rodway has reviewed and verified, to the best of his knowledge, the scientific and technical data in this news release. Verification included review of field notes, sample tags, analytical certificates from Bureau Veritas Labs, and comparison of results to original data sets. No limitations were noted during the verification process.

ABOUT CORE SILVER CORP.

Core Silver Corp. is a Canadian mineral exploration company focused on the acquisition and development of mineral projects in British Columbia, Canada. The Company currently holds 100% ownership in the Blue Property Mineral Tenure, which covers a land area of114,074 hectares (~1,140 km²). The project lies within the Atlin Mining District, a well-known gold mining camp located in the unceded territory of the Taku River Tlingit First Nation and the Carcross/Tagish First Nation. The Blue Property hosts a major structural feature known as The Llewellyn Fault Zone ("LFZ"). This structure is approximately 140km in length and runs from the Tally-Ho Shear Zone in the Yukon, south through the Blue Property to the Alaskan Panhandle Juneau Ice Sheet in the United States. Core Silver believes that the south Atlin Lake area and the LFZ has been neglected since the last major exploration campaigns in the 1980's. The LFZ plays an important role in mineralization of near surface metal occurrences across the Blue Property Mineral Tenure. The past 50 years have seen substantial advancements in the understanding of porphyry, skarn, and carbonate replacement type deposits both globally and in British Columbia's Golden Triangle. The Company has leveraged this information at the Blue Property Mineral Tenure to tailor an already proven exploration model and believes this could facilitate a major discovery. Core Silver is excited to become one of Atlin Mining District's premier explorers where its team believes there are substantial opportunities for new discoveries and development in the area.

On Behalf of the Board of Directors

CORE SILVER CORP.

"Nicholas Rodway"

President & CEO
Tel: 604.681.1568

Neither the Canadian Securities Exchange nor its Regulation Services Provider (as that term is defined in the policies of the CSE) accepts responsibility for the adequacy or accuracy of this release.

FORWARD LOOKING STATEMENTS

Statements in this document which are not purely historical are forward-looking statements, including any statements regarding beliefs, plans, expectations, or intentions regarding the future. Forward looking statements in this news release include, but are not limited to, that drilling at the Silver Lime Polymetallic Project will follow the drilling program at the Laverdiere Copper Project; that the first target of the 2025 drilling program will focus on the Valley Zone; and any other general statement regarding the Company's planned or future exploration efforts at the Blue Property. It is important to note that the Company's actual business outcomes and exploration results could differ materially from those in such forward-looking statements. Risks and uncertainties include that the Company may not, due to environmental, technological and other factors, be successful in expanding the mineralization footprint of the Projects as planned; that the Company may be unable to implement its plans to drill at the Silver Lime Polymetallic Project after drilling at the Laverdiere Copper Project, as intended; that the Company may not be able to focus on the intended drill targets, such as planned drill target at the Valley Zone; that the Company may be unable to implement its plans to further explore at the Silver Lime Project and the Laverdiere Project, as applicable; that certain exploration methods, including the Company's proposed exploration model for the Blue Property, may be ineffective or inadequate in the circumstances; that economic, competitive, governmental, geopolitical, environmental and technological factors may affect the Company's operations, markets, products and prices; our specific plans and timing drilling, field work and other plans may change; that the Company may not have access to or be able to develop any minerals because of cost factors, type of terrain, or availability of equipment and technology; and we may also not raise sufficient funds to carry out or complete our plans. The ongoing COVID-19 pandemic, labour shortages, inflationary pressures, rising interest rates, the global financial climate and the conflict in Ukraine and surrounding regions are some additional factors that are affecting current economic conditions and increasing economic uncertainty, which may impact the Company's operating performance, financial position, and prospects. Collectively, the potential impacts of this economic environment pose risks that are currently indescribable and immeasurable. No assurance can be given that any of the events anticipated by the forward-looking statements will occur or, if they do occur, what benefits the Company will obtain from them. Readers are cautioned that forward-looking statements are not guarantees of future performance or events and, accordingly, are cautioned not to put undue reliance on forward-looking statements due to the inherent uncertainty of such statements. Additional risk factors are discussed in the section entitled "Risk Factors" in the Company's Management Discussion and Analysis for its recently completed fiscal period, which is available under the Company's SEDAR profile at www.sedar.com. Except as required by law, the Company will not update or revise these forward-looking statements after the date of this document or to revise them to reflect the occurrence of future unanticipated events.

SOURCE: Core Silver Corp.

View the original press release on ACCESS Newswire

FAQ

What did Core Silver (CCOOF) announce on October 20, 2025 about Laverdiere?

Core Silver announced a new copper-bearing porphyry vein discovery at Copper Creek and said mineralization now spans a 4.5-km area.

What were the highest surface assay results reported by Core Silver (CCOOF) at Copper Creek in 2025?

Surface assays reported up to 1.35% Cu with 9.1 g/t Ag and 0.63% Cu with 17 g/t Ag and 355 ppm Mo.

How far is the new Copper Creek porphyry from the Valley Fault Zone noted by Core Silver (CCOOF)?

The new porphyry vein system is approximately 2.6 kilometres south of the Valley Fault Zone.

Does the October 20, 2025 Core Silver (CCOOF) release include drilling results?

No—additional 2025 exploration and drilling results were not released yet; the company said they will be provided as available.

What evidence supports a district-scale system at Laverdiere according to Core Silver (CCOOF)?

Core Silver cited widespread Cu-Mo-Ag assays, cross-cutting porphyry and epithermal veining, and a 4.5-km mineralized footprint as evidence.