Caledonia Mining Unveils New Gold Mineralisation Zone at Zimbabwe's Blanket Mine

Surface Exploration Defines New Gold Zone at K-Pits Target

On 23 July 2026, Caledonia Mining announced that its surface exploration at the Blanket mine has delineated a previously unrecognized gold mineralisation zone at the K-Pits target within the Blanket mining lease. Initiated in 2024 with geological mapping and geophysical surveys, the exploration successfully identified significant near-surface gold mineralisation in both oxide and sulphide forms. This mineralised zone appears to be a separate orebody not exploited by existing underground mining operations, offering new exploration and development prospects.

In 2025, the company conducted extensive fieldwork, including 2,304.1 metres of trenching across 13 trenches and 7,063 metres of shallow reverse circulation (RC) drilling at K-Pits. Drilling was performed on an approximate 25 by 25-metre grid, with 155 RC holes inclined at about 60 degrees west to an inclined depth of 45 metres (around 40 metres vertical depth). All samples underwent fire assay and bottle roll assay at independent laboratories, with certified reference materials and blanks included to ensure data integrity.

Drilling Highlights Reveal Strong Gold Grades Across Multiple Horizons

Selected drilling results from the K-Pits programme confirm significant gold mineralisation in both oxide and deeper sulphide zones. Hole KPT0EX2553 returned 23.00 metres at 2.61 g/t gold from surface in the oxide zone. Hole KPT0EX2545 showed 15.00 metres at 1.69 g/t gold from surface in oxide, plus 4.00 metres at 2.08 g/t from 15 metres in the transitional zone. Hole KPT0EX2567 intersected 20.00 metres at 1.22 g/t gold from 19 metres downhole within the transitional zone, indicating mineral continuity at depth.

Deeper sulphide mineralisation also yielded notable grades: hole KPT0EX2510 intersected 16.00 metres at 6.04 g/t gold from 29 metres downhole, among the highest in the programme. Hole KPT0EX2542 returned 7.00 metres at 5.96 g/t from 13 metres downhole in sulphide, while hole KPT0EX2576 recorded 5.00 metres at 3.96 g/t from 40 metres downhole. The coexistence of shallow oxide and deeper sulphide zones suggests potential for near-term low-cost surface mining alongside longer-term underground exploration.

Oxide Gold Mineralisation Shows Promise for Heap Leaching

The near-surface oxide gold at K-Pits is particularly significant as it may be amenable to conventional heap leaching, offering a potentially lower-cost extraction method compared to underground mining. Metallurgical test work is ongoing to evaluate heap leach suitability, with preliminary results described as encouraging. This could complement Blanket's existing underground operations and enhance asset value.

CEO Mark Learmonth commented: "We have initiated metallurgical testing on Blanket's oxide material to assess heap leaching potential, with early results encouraging. Should recoveries prove acceptable, we plan to start a trial heap leach operation on 10,000 tonnes of material in the second half of 2026. Developing a low-cost processing route for this near-surface mineralisation could significantly complement Blanket's underground operations and unlock additional value." This indicates a phased development approach beginning with a trial operation before scaling.

Geological Context and Distinctness from Existing Underground Orebodies

Caledonia detailed the geological setting of the K-Pits discovery. The Blanket mine lies on the north-western limb of the Archaean Gwanda Greenstone Belt in south-western Zimbabwe, roughly 15 km northwest of Gwanda, the Matabeleland South provincial capital. Gwanda is 147 km southeast of Bulawayo and 197 km northwest of the Beitbridge border with South Africa. The Gwanda Greenstone Belt spans approximately 7 km west-east and 15 km north-south, typical of Zimbabwe Craton greenstone belts with mafic to felsic volcanics and interbedded sedimentary units.

Importantly, K-Pits mineralisation is about 200 metres east of the nearest projected underground orebody surface outcrop, suggesting a previously unexploited mineralised horizon. The mineralisation is associated with strong shearing and silicification along contacts between talc chlorite schist and surrounding metabasalts, indicating a distinct structural and lithological environment from existing underground workings.

Upcoming Resource Update and Ongoing Exploration Plans

Caledonia is progressing work to integrate surface exploration results into an updated Blanket resource statement, expected in August 2026. This update will include surface and recent underground drilling data at Blanket, alongside exploration results from the Motapa property, where initial drilling has also been encouraging. Incorporating K-Pits results will significantly enhance the mineral resource inventory and provide investors with an updated asset assessment.

Further drilling is planned from both surface and underground platforms to test potential extensions of the K-Pits mineralisation at depth. Management believes the discovery has lateral and depth extension potential warranting continued investigation. The consistent dip and orientation of Blanket’s orebody suggest predictable geometry for K-Pits mineralisation, guiding future drilling efforts.

Robust Quality Assurance and Control Ensure Data Integrity

The company implemented comprehensive QAQC protocols throughout the K-Pits drilling and sampling campaigns. These included systematic insertion and monitoring of certified reference materials (CRMs), blank samples (certified and field blanks), and duplicate samples (field, coarse reject, and pulp duplicates). QAQC samples were regularly inserted into the sample stream and analyzed by accredited laboratories, primarily Antech Laboratory Services in Zimbabwe, using industry-standard fire assay and multi-element techniques.

Results indicate the analytical data are generally reliable and suitable for mineral resource estimation. CRM standards showed acceptable to excellent accuracy and precision, with high-grade and low- to medium-grade standards reproducing certified values within control limits. Independent blank samples returned values near detection limits, showing no significant contamination. Isolated CRM failures were attributed to sample handling rather than laboratory issues.

Caledonia Mining's Broader Asset Portfolio and Strategic Outlook

Caledonia Mining Corporation operates gold mining assets and projects across Zimbabwe. The Blanket mine is its primary producing asset and main revenue source. Additional properties include the Bilboes development-stage project and the Motapa exploration property, both located north of Blanket within the same mineralised belt. Management views the entire portfolio as having significant exploration potential, with recent Motapa drilling results described as encouraging, indicating multiple prospective targets in the region.

The K-Pits discovery aligns with Caledonia’s broader strategy to expand Blanket’s mineral resource base through systematic surface exploration. After a period of limited exploration, the company initiated a phased surface exploration programme within the Blanket mining lease in 2025. This strategic shift towards active exploration targeting previously understudied areas has validated the approach, as demonstrated by the K-Pits results.

Potential Impact on Blanket Mine Economics and Development Timeline

The possibility of developing a low-cost heap leach operation on K-Pits’ oxide mineralisation could materially enhance Blanket’s economics and cash flow. Heap leaching is typically less capital-intensive and cheaper to operate than underground mining and milling. If metallurgical tests confirm acceptable recovery and the 2026 trial proves successful, Caledonia could generate additional cash flow from processing the 10,000-tonne trial and potentially larger volumes in the future.

The company is adopting a cautious, phased development strategy. The planned trial heap leach operation in the second half of 2026 is modest in scale to demonstrate technical and economic viability before committing to full-scale production. This approach mitigates risk by validating metallurgical and operational assumptions on actual ore. Concurrently, further drilling from surface and underground will evaluate resource expansion, potentially extending mine life and enhancing the attractiveness of heap leach development.

Exploration Methodology and Sampling Standards

The K-Pits exploration employed industry-standard trenching and RC drilling techniques. Thirteen trenches, up to 1.5 metres deep totaling 2,304.1 metres, were mapped for lithology and structure and sampled at 1-metre intervals from clean trench sidewalls. Samples were composited based on lithology and alteration domains, avoiding mixing across domains. Composite samples combined five samples in wider zones or two in narrow zones, homogenized and riffle-split into two 2-kilogram samples for analysis.

RC drilling incorporated strict contamination controls, including rig and splitter cleanliness checks before and during drilling. Sample bags were pre-numbered, with empty bags inserted where no sample was recovered to maintain chain of custody. Bulk samples were collected at 1-metre intervals and riffle-split into three: one 2-kilogram sub-sample for assay, a field duplicate, and chips for traying. Sampling intervals were verified by geologists against driller marks.

Strategic Location within a Prolific Regional Gold Belt

Blanket’s location in south-western Zimbabwe places it within the prolific Gwanda Greenstone Belt, a historically productive gold mining region containing multiple deposits. The K-Pits exploration initially targeted near-surface zones within the Blanket lease that had received limited prior attention, starting with trenching at the Sabiwa North Extension targeting the Banded Iron Formation (BIF) known from nearby mines. Focus then shifted northwards to K-Pits along the same lithological strike in the footwall of Blanket’s current production area.

The Gwanda Greenstone Belt is approximately 7 km long and 15 km wide, characterized by mafic to felsic volcanics interlayered with sedimentary units and subjected to strong deformation. The belt’s structural setting includes a major periclinal synform plunging northwest, flanked by deformation zones. Metamorphism reaches upper greenschist to amphibolite facies, higher than typical Zimbabwean greenstone belts. These geological features create favorable conditions for gold mineralisation associated with shear zones and lithological contacts, as confirmed by the K-Pits discovery. Despite mature exploration in the region, systematic targeting of previously understudied areas like K-Pits continues to reveal new resources.