Midnight Sun Intercepts 1.0% Copper over 22 Metres and 0.98% Copper over 15 Metres at Dumbwa

Rhea-AI Summary

Midnight Sun Mining Corp (MDNGF) reported additional drill assays from the Dumbwa target on November 18, 2025, confirming mineralization along nearly 1.5 kilometres of strike. Key intercepts include 1.00% Cu over 22 m (DBW-25-010) and 0.98% Cu over 15 m (DBW-25-009). The company has completed 51 holes with 5 ongoing and plans a further 75 holes (~15,000 metres) to test an additional ~3 km of strike. Five drill rigs are active, a sixth is expected in early 2026, and continuous drilling is planned through the rainy season with forecasted ~90% productivity. Reported intervals are drill lengths and not true widths; assays used four-acid digest with ICP-OES finish at SGS Kalulushi.

Positive

• Nearly 1.5 km mineralised strike defined
• DBW-25-010: 1.00% Cu over 22 m
• DBW-25-009: 0.98% Cu over 15 m
• 75 holes (~15,000 m) planned to test next 3 km
• Five drill rigs active; sixth expected early 2026

Negative

• Reported intervals are drill lengths, not true widths
• Expected ~10% productivity loss during rainy season (90% productivity)

Dumbwa drilling has now established strike over nearly 1.5 kilometres

Vancouver, British Columbia--(Newsfile Corp. - November 18, 2025) - Midnight Sun Mining Corp. (TSXV: MMA) (OTCQX: MDNGF) ("Midnight Sun" or the "Company") is pleased to report assay results from additional holes at the Dumbwa target. Diamond drill hole DBW-25-009 intercepted 0.98% Cu over 15 metres and 0.79% Cu over 5.25 metres. Hole DBW-25-010 intercepted 1.0% Cu over 22 metres. Additional significant intercepts are provided in the table below.

Hole ID		From (m)	To (m)	Interval (m)	Cu (%)
DBW-25-006		142	153	11	0.25
	and	159	163	4	0.18
	and	167	171	4	0.20
DBW-25-009		119.75	125	5.25	0.79
	and	155	170	15	0.98
	and	178	186	8	0.36
DBW-25-010		45	54	9	0.31
	and	101	110	9	0.32
	and	117	139	22	1.00

 

Assay results based on four-acid digest, ICP-OES Finish. Intervals listed are based on drilling intervals and therefore are considered relative rather than true widths.

Midnight Sun's COO, Kevin Bonel, states, "We continue to deliver rapid progress at Dumbwa, effectively expanding the strike length, and continuing to refine our geological model. With nearly 1.5 kilometres of mineralised strike defined to-date, and the full scale of Dumbwa coming sharply into focus, our confidence in the system's size, high-grade potential, and significance has never been higher. Momentum is firmly on our side as we drive aggressively through the remainder of 2025, fully aligned with our goal of systematically delineating the strike potential of Dumbwa.

To accelerate our exploration, we have expanded our geological team to maximize core cutting and logging efficiency. With five drill rigs turning, a sixth expected in early 2026, and continuous drilling planned through the rainy season, we are advancing this discovery with conviction."

Geologically, Dumbwa continues to bear a strong similarity to Barrick Mining's Lumwana Mine. Mineralised host rocks vary from two-mica foliated gneiss to mineralised biotite-amphibolite schists within a barren banded grey gneiss and pink gneiss package.

The mineralised trend is strongly orientated north-south and appears to be very steeply inclined. Drilling has already demonstrated nearly 1.5 kilometres of mineralised strike.

The centremost part of the north-south mineralised corridor tends to contain significant bornite and chalcopyrite. On either side of this north-trending centre, the mineralisation intensity slowly decreases and becomes more chalcopyrite-dominated. In addition to bornite-chalcopyrite disseminated mineralisation in the well-mineralised central zone, there are occasional rich bornite-chalcopyrite-quartz-feldspar veins that have a significant positive impact on copper grade.

The continued strong coincidence of soil anomaly, induced polarization chargeability and VTEM geophysics, against a well supported geological and structural model is allowing precise drill targeting as the mineralised corridor is traced and drill tested northwards.

Dumbwa Drill Program Update

To date, 51 holes have been completed with 5 holes ongoing and a further 75 holes called for in the immediate plan to test the mineralised corridor over the next 3 kilometres of strike. This represents approximately 15,000 metres of planned drilling.

In consultation with the drill contractors, Midnight Sun has chosen to maintain exploration operations through the rainy season, anticipating approximately 90% productivity (metres per rig per shift) due to expected weather-related delays. Otherwise, the program is expected to continue without interruption.

Samples from an additional 11 drill holes have been submitted for assay, with the remaining samples currently being cut and prepared.

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Quality Control/Quality Assurance

Drilling was conducted using a conventional diamond drilling rig and drill core was captured for the entirety of each hole and placed into plastic core trays. All drill holes were cored in PQ until stable ground was achieved and then reduced to HQ size for the remainder of each hole. Sampling was based on visible copper mineralization and sample intervals honoured any important lithological boundaries. Core was then cut in house using a diamond saw and the right half of core was placed into a 200 micron plastic bag, assigned a unique sample number, and recorded into GeoSpark logging system. Samples always remained under the supervision of Midnight Sun staff to maintain chain of custody. All samples were then delivered to SGS Labs located in Kalulushi, Zambia, a fully accredited laboratory. Once received, the samples were sorted, dried, crushed, and pulverized (SGS code PRP90) followed by four-acid digest with ICP-OES finish (SGS Code ICP42S). Copper range of detection is 0.01-10%. Midnight Sun follows an in-house QA/QC program that consisted of a random insertion every 10^th sample of either a coarse blank, fine blank, coarse duplicate, fine duplicate, or Certified Reference Material (standards).

Location of Reported Drill Holes

Hole ID	Type	XCOORD	YCOORD	Azimuth	Dip	EOH (m)
DBW-25-001	Diamond	440375	8627810	90	-70	386.00
DBW-25-002	Diamond	440770	8628758	270	-50	218.50
DBW-25-004R	Diamond	440924	8628758	270	-60	223.90
DBW-25-005	Diamond	440435	8627812	90	-60	294.20
DBW-25-006	Diamond	440670	8627812	270	-60	200.65
DBW-25-009	Diamond	440450	8627310	270	-60	260.00
DBW-25-010	Diamond	440300	8627310	90	-50	170.10

 

Note: Projection: WGS84, Zone 35 South

Qualified Person: Darin Labrenz, P.Geo., a consulting geologist for the Company and Qualified Person under NI 43-101, has reviewed and approved the technical data and contents of this release.

About Midnight Sun

Midnight Sun is focused on exploring our flagship Solwezi Project, located in Zambia. Situated in the heart of the Zambia-Congo Copperbelt, the second largest copper producing region in the world, our property is vast and highly prospective. Our Solwezi Project is surrounded by producing copper mines, including Africa's largest copper mining complex right next door, First Quantum's Kansanshi Mine. Led by an experienced geological team with multiple discoveries and mines around the world to their credit, Midnight Sun's goal is to find and develop Zambia's next generational copper deposit.

ON BEHALF OF THE BOARD OF MIDNIGHT SUN MINING CORP.
Al Fabbro
President & CEO

For Further Information Contact:
Adrian O'Brien
VP Business Development and Communications
Tel: +1 604 809 6890
Em: adrian@midnightsunmining.com

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This news release contains "forward-looking statements" within the meaning of the applicable Canadian securities legislation that are based on expectations, estimates, assumptions, geological theories, and projections as at the date of this news release. The information in this news release about any information herein that is not a historical fact may be "forward looking statements." Any statement that involves discussions with respect to predictions, expectations, beliefs, plans, projections, objectives, assumptions, future events or performance (which may, but not always, include phrases such as "anticipates", "expects", "plans", "scheduled", "believed" or "intends" or variations of such words and phrases or stating that certain actions, events or results "may" or "could", "would", "might" or "will" be taken to occur or be achieved) are not statements of historical fact and may be forward-looking statements and are intended to identify forward-looking statements.

Although the forward-looking statements contained in this news release are based upon what management believes, or believed at the time, to be reasonable assumptions, the Company cannot assure readers that actual results will be consistent with such forward-looking statements, as there may be other factors that cause results not to be as anticipated, estimated or intended. Such factors include, among others, risks relating to the timing and ability of the Company to obtain and the timing of the approval of relevant regulatory bodies, if at all; risks relating to property interests; risks related to access to the project; risks inherent in mineral exploration, including the fact that any particular phase of exploration may be unsuccessful; the availability of contractors; geo-political risks; the global economic climate; metal prices; environmental risks; political risks; and community and non-governmental actions. Further to this, geological similarities or characteristics are not guarantees or certainties of successful exploration. Neither the Company nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking statements. The Company does not undertake, and assumes no obligation, to update or revise any such forward-looking statements or forward-looking information contained herein to reflect new events or circumstances, except as may be required by law.

To view the source version of this press release, please visit https://www.newsfilecorp.com/release/274960

FAQ

What copper grades did MDNGF report at Dumbwa on November 18, 2025?

Key assays include 1.00% Cu over 22 m (DBW-25-010) and 0.98% Cu over 15 m (DBW-25-009).

How much mineralised strike has Midnight Sun (MDNGF) defined at Dumbwa?

The company reports nearly 1.5 kilometres of mineralised strike defined to date.

How many drill holes and metres does MDNGF plan next at Dumbwa?

Midnight Sun plans a further 75 holes (~15,000 metres) to test about 3 km of strike.

How many drill rigs are operating on the MDNGF Dumbwa program and when is a sixth expected?

Five drill rigs are active now; a sixth is expected in early 2026.

Are the reported intercept widths true widths for MDNGF Dumbwa assays?

No; the release states intervals are drilling intervals (not true widths) and are considered relative.

What laboratory and method did MDNGF use for the Dumbwa assays?

Samples were analyzed at SGS Kalulushi using four-acid digest and ICP-OES finish (SGS codes PRP90, ICP42S).