Tillkännagivande • Jun 29
Midnight Sun Mining Corp. Reports Additional Drilling Results At Dumbwa Copper Deposit
Midnight Sun Mining Corp. has reported additional results from 77 holes on its wholly owned Dumbwa copper deposit, located in Solwezi, Zambia. Drilling has now surpassed 260 holes and 56,855 metres, confirming continuous near-surface sulphide copper mineralization over 6.7 kilometres of strike at Dumbwa. Five drill rigs continue to expand the deposit northward along strike and laterally to the east and west of known mineralization. Highlights of Drilling include: DBW-26-200 intercepted 0.42% Cu over 21.6m. DBW-26-165 intercepted 0.51% Cu over 13.7m. DBW-26-150 intercepted 0.38% Cu over 25.0m. The Dumbwa deposit is a 6,700 metre long and 600 metre to 1,000 metre wide, north-south, strain-controlled copper system. It is typically near, or at, surface, and extends to greater than 200 metres depth. It features a high-grade, central corridor ranging in width from 100 to 600 metres within a broader mineralized shell which can exceed 1,000 metres in width. Initial, discovery drilling is broadly spaced with holes positioned 50 to 100 metres apart on each of the east-west lines, with the lines spaced 100 to 200 metres apart north to south. On any individual line/section, only 2 or 3 holes are positioned within the highest-grade corridor, while a higher percentage of holes are positioned in the lower-grade shells. The higher-grade core shows strong grades and continuity within individual segments of the deposit. As drilling has progressed north of the disruption zone, there is good development of visually strong copper mineralization and the northernmost holes reported demonstrate the return of thick, higher-grade mineralization within the central corridor of the deposit. The Company will host a technical webinar with Midnight Sun’s COO, Dr. Kevin Bonel, to discuss the results announced in this news release on Tuesday, June 30th, 2026, at 10am PST. Drilling Highlights Table: Hole ID From (m) To (m) Interval (m) Cu (%) DBW-26-200 0.36 22.00 21.64 0.42 DBW-26-180 0.00 21.00 21.00 0.21 DBW-26-177 3.50 29.00 25.50 0.18 DBW-26-176 3.00 27.30 24.30 0.27 and 35.00 53.70 18.70 0.27 DBW-26-165 19.33 33.00 13.67 0.51 DBW-26-159 144.00 172.00 28.00 0.25 DBW-26-150 97.00 122.00 25.00 0.38 and 151.8 174.00 22.20 0.25 and 195.00 209.00 14.00 0.38 DBW-26-142 197.07 215.00 17.93 0.23 and 218.75 231.00 12.25 0.26 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. The full table of assays including locations is available on the Company’s website and can be accessed through this link: Dumbwa Drill Hole Location and Assay Table. Drilling has now intersected continuous near-surface sulphide copper mineralization over 6.7km of strike at Dumbwa. Assays have been received for the first approximately 5.2km of the drilled trend, and five drill rigs are continuing northward along strike and laterally to the east and west of known mineralization. Recent drilling has focused on the continued expansion of the Dumbwa Deposit northward, while also refining the lateral boundaries of mineralization, which has resulted in an additional 1.4km of strike extension to the north. This drilling intersects the same geology that characterizes Dumbwa, comprising flat - to gently east-dipping biotite and muscovite-biotite schists hosting sulphide copper mineralization. The higher-grade core of the north-south-trending Dumbwa shear zone has re-emerged beyond the northwest-southeast structural corridor, where weaker schist development and associated grade attenuation had previously been encountered. Mineralization remains open along the full extent of the copper-in-soil anomaly, in select areas to the east and west, and at depth. Approximately 12,500m of Phase One drilling remains to complete the planned testing of the initial 11.5km strike extent, with the program expected to conclude in Third Quarter 2026. The objective has been to define the Dumbwa deposit quickly, methodically, and completely. From the outset, the drill program has been designed to test the full mineralized envelope, which includes the higher-grade core as well as the surrounding lower-grade mineralization, in order to define the overall dimensions and continuity of the system. Drill fences are spaced approximately every 100 to 200m along the 20km strike of the target area, with drill holes positioned every 50 metres across each east-west fence. Beginning at the southern property boundary, drilling has progressively advanced northward, systematically building the deposit one fence at a time. This approach has now defined a mineralized system extending approximately 6.7km in strike length. The central higher-grade zone is typically between 200 and 600m wide with the total mineralized envelope commonly extending from 1.0 to 1.5km across. Each drill fence typically contains only two to three holes within the higher-grade core, while many holes test the surrounding lower-grade mineralization. Demonstrating the full width and continuity of the mineralized system requires drilling to its margins rather than focusing exclusively on the higher-grade centre. By systematically drilling the entire mineralized corridor, both the geometry of the higher-grade core and the full extent of the broader mineralized system are being established. Viewed as a table of drill intersections, many holes appear to return lower grades. Viewed in their geological context, however, those same holes are defining the boundaries of a large, continuous mineralized system while progressively delineating the significant higher-grade core within it. Dumbwa drilling to date, plotted on 11.5km Phase One copper-in-soil anomaly, target area. Dumbwa drilling to date, magnified to show current 5.3km drilled strike extent, plotted on Phase One copper-in-soil anomaly, target area. Assay grade shells superimposed on the Dumba soil anomaly showing the correlation between high soil anomalies and medium to high grade mineralised intercepts at Dumbwa. Drilling continues to follow the soil anomaly north. 11.5 kilometre Phase One Target area - Assay grade shells superimposed on the Dumba soil anomaly showing the correlation between high soil anomalies and medium to high grade mineralised intercepts at Dumbwa. Drilling continues to follow the soil anomaly north. 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 mineralisation, and sample intervals honoured any important lithological boundaries.