Meridian Drills Into Shallow High-Grade Cu-Au-Zn & Ag Massive to Semi-Massive Sulphides on the Open Western Limit of Santa Helena

Rhea-AI Summary

Meridian Mining (OTCQX:MRRDF) has announced significant drilling results at its Santa Helena Au-Cu-Ag & Zn deposit. The key highlight is drill hole CD-651, which intercepted 33.4m @ 2.0g/t AuEq (1.4% CuEq), including 13.1m @ 4.2g/t AuEq (2.8% CuEq) from shallow depths.

Additional notable results include CD-655 returning 9.9m @ 5.6g/t AuEq (3.7% CuEq) from 3.8m in the mine area infill drilling. The company has also discovered a new 2,200m copper-gold soil anomaly at Santa Fé, located 5km southeast of Santa Helena, with peak values of 547 ppm Cu, 2539 ppm Pb, 1135 ppm Zn, and 65 ppb Au.

The western extension of Santa Helena remains open for further exploration, and the company has revised its timeline for mineral resource estimation to H2 2025. Metallurgical studies are ongoing to optimize metal recovery from various geometallurgical domains.

Positive

• High-grade shallow mineralization discovered in western extension: CD-651 with 33.4m @ 2.0g/t AuEq
• New Cu-Au-Zn discovery at Santa Fé with 2,200m soil anomaly
• Multiple zones of massive to semi-massive VMS mineralization identified
• Potential for expansion as mineralization remains open at both ends of Santa Helena

Negative

• Mineral resource estimation delayed to H2 2025 due to additional drilling requirements
• Some historical drill holes were too shallow or partially un-assayed, limiting previous deposit interpretation

Highlights:

• Meridian drills into a VMS pile hosting massive to semi-massive Cu-Au-Zn & Ag sulphides on the western edge of Santa Helena:

  • CD-651: 33.4m @ 2.0g/t AuEq (1.4% CuEq) from 151.0m;

    • Including:

      • 13.1m @ 4.2g/t AuEq (2.8% CuEq) from 151.4m;

  • 4.4m @ 6.5g/t AuEq (4.4% CuEq) from 214.0m;

• Santa Helena mine area infill drilling returns more shallow high-grade mineralization;

  • CD-655: 9.9m @ 5.6g/t AuEq (3.7% CuEq) from 3.8m;

• Meridian announces discovery of "open" 2,200m copper-gold soil anomaly at Santa Fé; and

  • Potential for Santa Helena to be a second hub within the Cabaçal belt strengthens.

LONDON, UK / ACCESS Newswire / April 15, 2025 / Meridian Mining UK S (TSX:MNO)(Frankfurt/Tradegate:2MM)(OTCQX:MRRDF) ("Meridian" or the "Company") is pleased to announce that it has drilled laterally into a VMS pile hosting Cu-Au-Zn & Ag massive to semi-massive sulphides on the western limit of the Santa Helena Au-Cu-Ag & Zn deposit "Santa Helena". CD-651 returned 33.4m @ 2.0g/t AuEq (1.4% CuEq) including 13.1m @ 4.2g/t AuEq (2.8% CuEq). Potential exists for further Cu-Zn-Au rich domains to the west, where it is considered open. Drilling continues and further results are pending.

The Company is also announcing that its exploration team has defined a new Cu-Au and Zn discovery at Santa Fé ("Santa Fé"), 5km southeast of Santa Helena. Santa Fé hosts an open Cu-Au-Zn soil geochemical anomaly extending over 2,200m with a coincident Induced Polarization ("IP") anomaly. Further geophysical and surface mapping is ongoing with Santa Fé projected to be drill ready by late in Q2.

Mr. Gilbert Clark, CEO, comments: "CD-651 returned multiple shallow layers of massive to semi-massive, and disseminated sulphides, hosting high-grades of Au-Cu-Ag & Zn mineralization starting at only 26m below surface. With CD-651's strong sulphides, it now makes the whole of the Santa Helena system resemble a string of precious and base metal pearls, just like the black smokers that create VMS deposits. The mineralization at both ends of Santa Helena remains open for extensions and more drilling is needed to close-off and in-fill this system. I believe that by combining this growth at Santa Helena with the exciting Santa Fé discovery the potential for a future second mining Hub centred on Santa Helena is apparent. This growth potential builds on the exceptional PFS results for Cabaçal^[1], and this is why Meridian's Cabaçal project is Brazil's and South America's most prospective Cu-Au VMS belt."

Santa Helena Drilling
The Santa Helena drill program continues to build the resource potential of the western sector of the exploration target area, ("Figure 1"). New mineralization has been defined in areas where the VMS sheet had not previously been projected. CD-651's success in intercepting shallow semi-massive to massive high-grade VMS mineralization confirms that this western extension of Santa Helena's system is open, and more continuous than originally modelled ("Table 1"). Drilling from the 2024 campaign in this western extension had outlined a gold-rich shallow zone, with drill holes CD-539, CD-600, CD-605, and CD-612^[2] outlining a mineralized position considered to be up to 15-17m thick. CD-651's further western extensions of this Au-Cu-Ag & Zn mineralization, importantly indicates that some of the historical holes stopped short of the mineralization or failed to fully assay the VMS horizon.

It is apparent after reviewing the Company's recent drill results, that the previous interpretation of the Santa Helena western edge, limited the size of the deposit due to historical drill holes being too shallow (PM-26A) or being partially un-assayed (PM-25A) ("Figure 2"). In addition, Meridian's field validation checks suggested that one mineralized hole, JUCHD-056, was mislocated in the historical database. Meridian's continued success in intercepting high-grade Au-Cu-Ag & Zn mineralization, indicates a far stronger and open system than historically modelled. As a result of this success, additional drilling is needed to close off this western zone of Santa Helena's mineralization before a mineral resource can be estimated; this will now be later in H2, 2025.

Figure 1: Santa Helena drilling highlights.

Lateral drilling has continued at a low angle while the Company evaluates options to establish alternative platforms. Following adaptations to the drill rig, CD-651 extended further west than the Company's previous limits of drilling. The recent results of CD-651 have returned multiple zones of semi-massive to massive VMS mineralization:

• 41.2m @ 0.9g/t AuEq (0.6% CuEq) from 78.0m;

  • Including: 5.1m @ 1.6g/t AuEq (1.1% CuEq) from 102.7m;

• 33.4m @ 2.0g/t AuEq (1.4% CuEq) from 151.0m;

  • Including: 13.1m @ 4.2g/t AuEq (2.8% CuEq) from 151.4m;

• 4.4m @ 6.5g/t AuEq (4.4% CuEq) from 214.0m;

Figure 2: Section showing Meridian drilling along CD-651 projection, in relation to historical drilling and historical mineralization envelope model. Black drill traces are un-assayed intervals, coloured traces indicate assayed intervals

In addition, new results from drill holes in this western position include:

• CD-624: 73.7m @ 1.0g/t AuEq (0.7% CuEq) from 22.6m;

  • Including: 22.4m @ 1.5g/t AuEq (1.0% CuEq) from 22.6m;

• CD-643: 30.3m @ 1.2g/t AuEq (0.8% CuEq ) from 66.4m;

  • Including: 7.6m @ 2.5g/t AuEq (1.7% CuEq ) from 66.4m;

• CD-661: 46m @ 1.5g/t AuEq (1% CuEq ) from 2.0m

  • Including 7.6m @ 2.6g/t AuEq (1.7% CuEq ) from 2.0m

  • And 41.7m @ 0.9g/t AuEq (0.6% CuEq ) from 54.0m

Metallurgical studies continue assessment of optimizing metal recovery from this and other geometallurgical domains.

Drilling over the main sheet includes a combination of infill and verification drilling, where incomplete historical data has created uncertainty in the modelling approach. An angled hole, CD-618, was drilled where hole PM-10A terminated at 27.5m, having been sampled to 27.1m with some doubt as to whether it traversed the full layer. CD-618 intersected 2.9m @ 3.7g/t AuEq from 40.8m in the VMS position, with additional mineralization intercepted in the footwall positions, including 4.8m @ 1.6g/t AuEq (1.0% CuEq) from 54.4m. These may represent multiple exhalative positions or possibly sub-seafloor replacement, which may have potentially to strengthen.

Two historical holes were twinned (JUCHD-100, JUCHD-112) where composites had been recorded but for which individual assays were lost, making the holes unsuitable for resource estimation. Twin holes returned:

• CD-655: 9.9m @ 5.6g/t AuEq (3.7% CuEq) from 3.8m;

  • Including: 6.7m @ 7.5g/t AuEq (5.1% CuEq) from 6.0m; and

• CD-652: 7.0m @ 1.8g/t AuEq (1.2% CuEq) from 10.3m.

The more complete data enables better modelling of the VMS horizon where the partial data implied a more restricted extent.

Santa Fé Exploration Discovery
Through the Company's regional exploration programs, a new target area in the southeast of the Cabaçal Belt, Santa Fé, (" Figure 3") has returned multiple strong surface geochemical anomalies ("Figure 4"), in a position not defined by historical exploration campaigns. A soil survey grid extending over 2.2km has returned peak values of 547 ppm Cu, 2539 ppm Pb, 1135 ppm Zn, and 65 ppb Au. Alluvial cover constrains the geochemical effectiveness of the grid extensions. The area has limited exposure but subcrop and float characteristic of the chlorite-altered mine sequence succession were observed, with rock chips returning up to 0.40% Cu, 0.79g/t Au, 1.1g/t Ag, 0.38% Zn, 0.36% Pb & 47 ppm Bi (a strong pathfinder element for gold at Cabaçal). The Company has completed 3 trenches for 292m to gather initial information on the basement structure in the central and southern sector of the area. The anomalous corridors align with west-dipping contacts between meta-volcanic and sedimentary rocks considered correlative with the mine sequence at Cabaçal and Santa Helena. Geophysical programs have been ongoing to refine drill targets. Santa Fé is located ~ 5km southeast of Santa Helena.

Figure 3: Newly located soil anomaly at Santa Fé, ~5km southeast of Santa Helena, marking a potential fold-repeat of the VMS stratigraphic horizon. Background image is RTP tilt-derivative magnetics.

Figure 4: Copper-in soil geochemical response over Santa Fé, superimposed on a chargeability grid. Background image is RTP tilt-derivative magnetics.

Technical Notes
Samples have been analysed at ALS laboratory in Lima, Peru. Samples are dried, crushed with 70% passing 85% passing 200µm. Routine gold analyses have been conducted by Au‐AA24 (fire assay of a 50g charge with AAS finish). High‐grade samples (>10g/t Au) are repeated with a gravimetric finish (Au‐GRA22), and base metal analysis by methods ME-ICP61 and OG62 (four acid digest with ICP-AES finish). Visible gold intervals are sampled by metallic screen fire assay method Au‐SCR21. Samples are held in the Company's secure facilities until dispatched and delivered by staff and commercial couriers to the laboratory. Pulps and coarse rejects are retained and returned to the Company for storage. The Company submits a range of quality control samples, including blanks and gold and polymetallic standards supplied by Rocklabs, ITAK and OREAS, supplementing laboratory quality control procedures. Approximately 5% of archived samples are sent for umpire laboratory analysis, including any lots exhibiting QAQC outliers after discussion with the laboratory. In BP Minerals sampling, gold was analysed historically by fire assay and base metals by three acid digest and ICP finish at the Nomos laboratory in Rio de Janeiro. Silver was analysed by aqua regia digest with an atomic absorption finish. True width is considered to be 70-90% of intersection width, except for low-angle holes CD-624, CD-643, CD-651 and CD-661 which are considered to be ~20% of true width. Assay figures and intervals are rounded to 1 decimal place.

Gold equivalents for Santa Helena are based on metallurgical recoveries from the historical resource calculation, updated with pricing forecasts aligned with the Cabaçal PEA. AuEq (g/t) = (Au(g/t) * 65%Recovery) + (1.492*Cu(%) * 89%Recovery) + (0.474*Zn% * 89%Recovery)) + (0.013*Ag(g/t) * 61%Recovery)). CuEq (%) = (Cu(%) * 89%Recovery) + (0.318*Zn% * 89%Recovery)) + (0.67*Au(g/t) * 65%Recovery) + (0.0087*Ag(g/t) * 61%Recovery)). Metallurgical testwork is currently in progress to evaluate recoveries in primary lithologies and saprolite, with formulas to be updated based on revised recoveries pricing.

Induced polarization surveys have been conducted by the Company's in-house team utilizing its GDD GRx8-16c receiver and 5000W-2400-15A transmitter. Results are sent daily for processing and quality control to the Company's consultancy, Core Geophysics. Modelling of conductivity response is undertaken using industry-standard Maxwell software. Geophysical and geochemical exploration targets are preliminary in nature and not conclusive evidence of the likelihood of a mineral deposit.

Qualified Person Statement
Mr. Erich Marques, B.Sc., FAIG, Chief Geologist of Meridian Mining and a Qualified Person as defined by National Instrument 43-101, has reviewed, verified and approved the technical information in this news release.

About Meridian
Meridian Mining is focused on:

• The development and exploration of the advanced stage Cabaçal VMS gold‐copper project;

• The initial resource definition at the second higher-grade VMS asset at Santa Helena as the first stage of the Cabaçal Hub development strategy;

• Regional scale exploration of the Cabaçal VMS belt to expand the Cabaçal Hub strategy; and

• Exploration in the Jaurú & Araputanga Greenstone belts (the above all located in the State of Mato Grosso, Brazil).

The Pre-feasibility Study technical report (the "PFS Technical Report") dated March 31, 2025, entitled: "Cabaçal Gold-Copper Project NI 43-101 Technical Report and Pre-feasibility Study" outlines a base case after-tax NPV5 of USD 984 million and 61.2% IRR from a pre-production capital cost of USD 248 million, leading to capital repayment in 17 months (assuming metals price scenario of USD 2,119 per ounces of gold, USD 4.16 per pound of copper, and USD 26.89 per ounce of silver). Cabaçal has a low All-in-Sustaining-Cost of USD 742 per ounce gold equivalent & production profile of 141,000 ounce gold equivalent life of mine, driven by high metallurgical recovery, a low life-of-mine strip ratio of 2.3:1, and the low operating cost environment of Brazil.

The Cabaçal Mineral Reserve estimate consists of Proven and Probable reserves of 41.7 million tonnes at 0.63g/t gold, 0.44% copper and 1.64g/t silver (at a 0.25 g/t gold equivalent cut-off grade).

Readers are encouraged to read the PFS Technical Report in its entirety. The PFS Technical Report may be found under the Company's profile on SEDAR+ at www.sedarplus.ca and on the Company's website at www.meridianmining.co

The PFS Technical Report was prepared for the Company by Tommaso Roberto Raponi (P. Eng), Principal Metallurgist with Ausenco Engineering Canada ULC; Scott Elfen (P. E.), Global Lead Geotechnical and Civil Services with Ausenco Engineering Canada ULC; John Anthony McCartney, C.Geol., Ausenco Chile Ltda.; Porfirio Cabaleiro Rodriguez (Engineer Geologist FAIG), of GE21 Consultoria Mineral; Leonardo Soares (PGeo, MAIG), Senior Geological Consultant of GE21 Consultoria Mineral; Norman Lotter (Mineral Processing Engineer; P.Eng.), of Flowsheets Metallurgical Consulting Inc.; and, Juliano Felix de Lima (Engineer Geologist MAIG), of GE21 Consultoria Mineral.

On behalf of the Board of Directors of Meridian Mining UK S

Mr. Gilbert Clark - CEO and Director
Meridian Mining UK S
8th Floor, 4 More London Riverside
London SE1 2AU
United Kingdom
Email: info@meridianmining.co
Ph: +1 778 715-6410 (BST)

Stay up to date by subscribing for news alerts here: https://meridianmining.co/contact/
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Further information can be found at: www.meridianmining.co

Cautionary Statement on Forward-Looking Information
Some statements in this news release contain forward-looking information or forward-looking statements for the purposes of applicable securities laws. These statements address future events and conditions and so involve inherent risks and uncertainties, as disclosed under the heading "Risk Factors" in Meridian's most recent Annual Information Form filed on www.sedarplus.ca. While these factors and assumptions are considered reasonable by Meridian, in light of management's experience and perception of current conditions and expected developments, Meridian can give no assurance that such expectations will prove to be correct. Any forward-looking statement speaks only as of the date on which it is made and, except as may be required by applicable securities laws, Meridian disclaims any intent or obligation to update any forward-looking statement, whether as a result of new information, future events, or results or otherwise.

Table 1: Assay Results from Santa Helena Drilling

Hole-id	Dip	Azi	EOH	Zone	Int	AuEq	CuEq	Au	Cu	Ag	Zn	Pb	From
			(m)		(m)	(g/t)	(%)	(g/t)	(%)	(g/t)	(%)	(%)	(m)
CD-661	-21	280	95.7	SHM		Subparallel Hole
					46.0	1.5	1.0	0.6	0.7	5.6	0.4	0.9	2.0
				Including	7.6	2.6	1.7	2.5	0.6	6.4	0.2	0.6	2.0
					41.7	0.9	0.6	0.0	0.2	5.6	1.4	0.0	54.0
CD-655	-90	000	25.2	SHM
					9.9	5.6	3.7	1.4	1.5	35.1	5.7	0.7	3.8
				Including	8.1	6.6	4.4	1.6	1.8	41.1	6.9	0.8	5.6
				Including	6.7	7.5	5.1	1.8	2.1	47.7	7.6	0.9	6.0
				Including	1.6	11.6	7.8	3.4	4.2	83.8	7.5	1.0	8.2
CD-652	-90	000	35.5	SHM
					6.7	0.3	0.2	0.0	0.1	3.2	0.3	0.1	0.9
					7.0	1.8	1.2	0.3	0.6	40.5	1.4	0.8	10.3
				Including	5.2	2.3	1.6	0.4	0.7	51.9	1.6	0.9	10.7
				Including	2.3	3.7	2.5	0.3	1.6	68.9	2.1	1.6	10.7
CD-651	-21	295	231.1	SHM		Subparallel Hole
					41.2	0.9	0.6	0.3	0.1	10.9	1.0	0.5	78.0
				Including	16.6	1.2	0.8	0.2	0.1	16.1	1.8	0.5	102.7
				Including	5.1	1.6	1.1	0.4	0.1	15.2	2.8	0.8	102.7
					2.4	0.9	0.6	0.7	0.1	16.8	0.6	0.2	132.0
					3.0	1.0	0.7	0.2	0.1	16.2	1.4	0.6	140.0
					33.4	2.0	1.4	0.3	0.3	24.4	3.1	0.7	151.0
				Including	13.1	4.2	2.8	0.4	0.6	48.4	6.5	1.2	151.4
				Including	5.9	5.7	3.8	0.5	0.7	65.2	9.2	1.8	151.4
				Including	3.4	5.9	4.0	0.6	1.0	66.3	8.8	1.4	161.0
					2.4	2.7	1.8	0.3	0.6	28.0	3.4	0.6	189.0
					4.4	6.5	4.4	0.4	0.6	65.6	11.6	2.1	214.0
CD-644	-71	186	45.1	SHM
					9.5	0.8	0.6	0.2	0.2	7.0	0.9	0.4	4.7
					3.2	0.6	0.4	0.2	0.1	3.6	0.8	0.0	17.2
					2.4	1.4	0.9	0.4	0.1	5.6	2.3	0.5	24.7
CD-643	-26	280	145.5	SHM		Subparallel Hole
					30.3	1.2	0.8	0.7	0.3	10.9	0.7	0.9	66.4
				Including	7.6	2.5	1.7	2.0	0.5	23.8	0.8	2.5	66.4
CD-637	-90	000	71.0	SHM
					0.9	1.7	1.2	0.4	0.7	11.2	1.0	0.1	31.2
					2.9	1.7	1.1	0.2	0.2	11.8	2.9	0.5	43.2
					1.1	1.7	1.1	0.6	0.1	20.1	2.5	1.2	50.7
CD-633	-21	009	119.3	SHM	NSR
CD-630	-66	315	85.9	SHM
					1.5	0.8	0.5	0.1	0.0	7.1	1.5	0.4	70.4
					0.5	1.4	0.9	0.0	0.3	5.7	2.4	0.3	75.2
CD-624	-21	290	140.3	SHM		Subparallel Hole
					73.7	1.0	0.7	0.3	0.4	8.9	0.7	0.3	22.6
				Including	22.4	1.5	1.0	0.8	0.6	13.7	0.4	0.9	22.6
				Including	15.5	1.8	1.2	1.0	0.6	14.2	0.4	1.0	22.6
				Including	8.1	2.2	1.5	1.4	0.8	5.6	0.6	0.7	22.6
					3.2	0.4	0.3	0.0	0.0	1.8	0.8	0.0	99.4
CD-621	-70	190	77.8	SHM	NSR
CD-618	-61	181	106.9	SHM
					2.9	3.7	2.5	0.8	0.9	30.7	4.2	0.9	40.8
					3.7	0.8	0.5	0.3	0.0	14.2	1.3	0.7	45.7
					4.8	1.6	1.0	0.9	0.0	39.4	1.5	1.1	54.4
					3.3	0.9	0.6	0.1	0.1	7.2	1.5	0.3	72.9
					2.1	1.7	1.1	0.8	0.1	17.8	2.3	1.2	79.0

^[1] Meridian Mining news release of March 10, 2025.

^[2]Meridian Mining news release of November 20^th and December 16, 2024.

SOURCE: Meridian Mining SE

View the original press release on ACCESS Newswire

FAQ

What are the latest drilling results from Meridian Mining's (MRRDF) Santa Helena project?

CD-651 intercepted 33.4m @ 2.0g/t AuEq (1.4% CuEq), including 13.1m @ 4.2g/t AuEq (2.8% CuEq) from shallow depths in massive to semi-massive sulphides.

What is the significance of Meridian Mining's (MRRDF) Santa Fé discovery?

Santa Fé represents a new 2,200m copper-gold soil anomaly with high-grade surface samples, located 5km southeast of Santa Helena, potentially indicating a second mining hub.

When will Meridian Mining (MRRDF) complete the mineral resource estimation for Santa Helena?

The mineral resource estimation for Santa Helena is scheduled for completion in H2 2025, delayed to accommodate additional drilling needed to close off the western zone.

What are the recent infill drilling results at Santa Helena mine area for MRRDF?

Recent infill drilling at Santa Helena mine area returned CD-655: 9.9m @ 5.6g/t AuEq (3.7% CuEq) from 3.8m, including 6.7m @ 7.5g/t AuEq.