Midnight Sun enlarges Dumbwa copper deposit to more than double in width to over 2.4 km in Northern Block, Zambia

Midnight Sun Mining Corp. [TSXV: MMA; OTCQX: MDNGF] reported that ongoing drilling at its Dumbwa copper deposit in Zambia has identified a significant expansion of the mineralized system in the Northern Block.

Recent drilling has encountered near-surface copper mineralization across an east-west extent exceeding 2,400 metres, which is more than double the average width of the previously drilled Dumbwa Mineralized Corridor. This expanded footprint represents a major development as the company advances its Phase Two exploration program, with drilling continuing to test the northern extent of Dumbwa and further define the distribution of copper mineralization within the broader system.

With the copper mineralization continuing to be flat-laying to shallowly dipping, and located at or very near surface, this is another promising development at Dumbwa.

“As drilling progresses north, we appear to have passed through another structural disruption and are now encountering copper sulphide mineralization across significantly greater east-west widths, with locally increased mineralized thicknesses. These observations are providing exciting insight into the geological architecture of the Northern Block and will help guide our ongoing exploration of this expanding system,” stated Dr. Kevin Bonel, Midnight Sun’s COO,

The company has, after lengthy delays due to ongoing issues at contracted analytical facilities, received results from 76 drill holes representing 17,373 metres of drilling. The results include assays from both the expansion and the delineation drill programs which are ongoing at Dumbwa.

Recent assay results continue to deliver multiple shallow, higher grade, copper intercepts within broader zones of copper sulphide mineralization. The results reported today are from holes drilled across various areas of the strike length of the deposit and include holes which had previously failed to meet the company’s QA/QC standards and were therefore not previously reported. Highlights include:

DBW-26-283: 0.47% Cu over 31.1 metres, including 0.81% Cu over 16.0 metres. DBW-26-261: 0.67% Cu over 11.0 metres. DBW-26-355: 1.05% Cu over 7.0 metres. DBW-26-266: 0.48% Cu over 14.0 metres.

Midnight Sun’s President and CEO, Al Fabbro, stated, “Phase One was designed to rapidly and systematically establish scale and outline the geological architecture of Dumbwa. I am extremely proud of what our team has accomplished, demonstrating more than 12 kilometres of mineralized strike length in just 14 months.

“Importantly, our ongoing drilling is now identifying a significant expansion of the mineralized system in the north, along with distinct zones of enhanced copper mineralization throughout the main corridor. The geological insights gained through Phase One are now allowing us to focus Phase Two drilling on the most prospective areas of the Dumbwa system.”

The field component of the company’s Phase 1 drill program is now complete, although some assays are still pending. The program, which consisted of 372 diamond drill holes totaling over 87,000 metres has demonstrated copper sulphide mineralization along more than 12 km of the Dumbwa Mineralized Corridor, comprising the southern portion of the broader 20 km Dumbwa Target as outlined by geophysics and soil sampling.

The Phase 1 drill program had two primary goals. The first goal was to discover the source of a laterally extensive, open ended, copper-in-soil anomaly which was previously outlined at Dumbwa, and located directly south of First Quantum Minerals’ Kansanshi Mine.

On this front, the program has been an unqualified success. With the discovery and emerging understanding of the Dumbwa copper deposit providing the Company and its shareholders with a unique asset, in a globally significant copper belt, at a time when the copper price is at or near its all-time highs.

The second goal was to quickly and efficiently define the full extent of Dumbwa. On that front, the program has also been highly successful, as demonstrated by the outlining of the copper system along strike for over 12 km and recently identifying a doubling in the width of the system as exploration continues to track Dumbwa northwards. However, this goal remains unfinished, for positive reasons, as the Dumbwa deposit remains open for further expansion to both the north and south.

The company has continued to experience extended assay turnaround times due to increased regional sample volumes, power interruptions and equipment failures at Intertek’s Kitwe preparation facility in Zambia.

Intertek has implemented measures to address these delays, including transferring samples to its outstanding samples for analysis in Perth, Australia.

Of the outstanding samples, 1,824 have now been received in Perth for priority analysis, with results targeted by October 30, subject to analytical completion and QA/QC requirements. A further 1,000 samples have been transferred to Johannesburg for preparation, while 859 samples remain in processing at Kitwe, with both batches expected to progress to Perth in the coming days.

Intertek has also committed to equipment upgrades at its Kitwe facility, including replacement pulverizing mills and an additional crusher, with commissioning targeted for December 1, 2026. These improvements are expected to increase processing capacity and improve turnaround times going forward. Approximately 5,000 samples, representing 70 drill holes remain outstanding.

Midnight Sun continues to utilize multiple laboratories and maintain its strict internal QA/QC procedures to ensure the reliability of reported results.

Ongoing Phase 2 Program: At this time, drilling is focused on the Northern Block of the Dumbwa Mineralized Corridor, where the company continues to be greatly encouraged by both the overall width of the mineralized zone and the local intensity of the mineralization observed during the logging of drill core from recent drill holes.

In addition, soil sampling continues in both the north and south of Dumbwa as the Company looks to generate additional targets that may sit outside of the established mineralized corridor.

Midnight Sun is rapidly advancing the Solwezi Copper Project, with a focus on our flagship Dumbwa copper deposit. The project is located near the town of Solwezi in the heart of the Zambia–Congo Copperbelt, the world’s second-largest copper-producing region. This prolific mining district is renowned for hosting multiple major copper deposits, and benefits from excellent infrastructure, an established mining workforce, and a long history of successful production.

The Solwezi Copper Project is surrounded by producing copper mines, including the geologically similar Lumwana mine to the west and First Quantum’s Kansanshi mine – Africa’s largest integrated metallurgical processing facility, approximately 6 km east of the company’s recently announced Kazhiba Oxide Resource. This highly favourable location highlights the district-scale potential of Midnight Sun’s land package.

The Dumbwa copper deposit underlays a robust 20-km copper-in-soil anomaly, and ongoing drilling has demonstrated strong geological similarities to the nearby Lumwana mine, underscoring the potential scale of this newly identified copper system.