Midnight Sun Mining identifies new copper targets at Dumbwa deposit

Midnight Sun Mining Corp (TSX-V:MMA, OTCQB:MDNGF) announced that it has identified multiple new exploration targets outside the previously defined and drilled mineralized corridor at its Dumbwa copper deposit in Solwezi, Zambia, following an initial high-resolution ground magnetic survey.

The survey covered an area of approximately 2.7 kilometres by 2.5 kilometres in the northern portion of Dumbwa’s Central Mineralized Block. Data was collected along north-south survey lines spaced 100 metres apart, with east-west tie lines spaced at 250-metre intervals.

Midnight Sun said the survey identified distinct magnetic signatures associated with drill-confirmed copper mineralization. Similar signatures were also identified in areas outside the known mineralized corridor that had not previously been identified or tested.

The company is extending the high-resolution magnetic survey across the full approximately 20-kilometre copper-in-soil anomaly. The expanded survey is designed to refine existing targets and identify additional prospective areas along parallel and sympathetic structural corridors with potential to host basement-hosted sulphide copper mineralization.

Midnight Sun COO Kevin Bonel said the survey has provided a clearer understanding of Dumbwa’s structural architecture and its relationship to higher-grade mineralized zones.

“Importantly, the survey has allowed us to ‘fingerprint’ the magnetic signature associated with the Central higher-grade block and identify several analogous targets east of the main mineralized corridor,” Bonel said.

“These targets will be prioritised for future drill testing and provide a compelling opportunity to identify significant additional copper mineralization and further expand Dumbwa’s rapidly growing footprint.”

Magnetic survey results

The initial survey produced two key findings. First, it identified a pattern of rapidly changing magnetic intensity within the northern portion of the Central Mineralized Block, an area that has previously returned several copper intercepts.

These include DBW-25-148, which returned 21 metres at 0.33% Cu; DBW-25-149, which returned 17.8 metres at 0.85% Cu and 21.4 metres at 0.38% Cu; and DBW-26-123, which returned 80 metres at 0.39% Cu.

Midnight Sun said the magnetic signature is interpreted to be associated with the geological and structural setting that hosts copper sulphide mineralization at Dumbwa and may provide an exploration tool for identifying additional prospective areas.

Second, the survey has allowed for better identification of late-stage faulting that may offset mineralization across Dumbwa, Midnight Sun Mining highlighted. The company said incorporating this structural information into drill planning is expected to improve the positioning of future drill collars for testing the main Dumbwa mineralized corridor.

The survey has generated two new, untested targets for basement-hosted sulphide copper mineralization approximately 1 to 1.2 kilometres east of the main Dumbwa mineralized corridor. Midnight Sun said the targets display magnetic characteristics similar to those observed in areas that have already returned higher-grade copper mineralization.

Drilling to test these targets is planned as part of Dumbwa’s Phase 2 exploration program, scheduled to begin in the third quarter of 2026.

The survey has also identified a similar magnetic pattern west of the main Dumbwa mineralized corridor. The company said this may represent an additional prospective structural corridor, with targets in the area currently being evaluated for potential inclusion in the Phase 2 exploration program.

Midnight Sun interprets the distinct, rapidly changing magnetic patterns observed within the Central Mineralized Block and at the newly identified targets as reflecting variations in the underlying lithology and structural architecture.

Competent feldspar pegmatites and amphibolites, which commonly contain higher concentrations of magnetite, are interpreted to define the margins of high-strain domains. These high-strain domains contain lower-magnetite schists that are interpreted to host the copper sulphide mineralization at Dumbwa.

Positive magnetic anomalies within the survey area also show a spatial relationship with the mineralized structural corridor that constrains the known Dumbwa sulphide copper occurrences.

Midnight Sun said preliminary interpretation indicates a positive relationship between magnetic intensity and zones of more intense copper sulphide mineralization observed in drill core and assay results. The company said this relationship is most apparent in the analytical signal data, but can also be observed in total magnetic intensity, first vertical derivative and second vertical derivative datasets.

The results support the company’s previous interpretation that the Dumbwa mineralized corridor is associated with a north-south oriented positive magnetic anomaly. Midnight Sun said the high-resolution magnetic survey may provide a tool for refining drill targeting and guiding future exploration along the full approximately 20-kilometre strike extent of the Dumbwa anomaly.

Diurnal correction was completed using a fixed magnetometer, while two mobile units were used to acquire magnetic data within the survey area.

Shares of Midnight Sun gained around 3.2% in Toronto on Thursday morning.