Kaoko Metals has confirmed broad, shallow copper-silver mineralisation at Otniel after its first two diamond holes returned strong grades, including intervals above 3% copper. The early results support expanded drilling across the 400km² Chalkos project, but true widths, continuity and metallurgy remain unresolved.
- 37.1m at 1.23% copper and 15.2g/t silver in DDOT001
- 48m at 1.02% copper and 12.9g/t silver in DDOT002
- Higher-grade zones reached 6.42% copper and 86g/t silver in individual samples
- Silver closely tracks copper across both holes
- Drilling continues at Otniel and Donkey Hill
First Otniel holes confirm copper-silver mineralisation
Kaoko Metals Limited (ASX:KAO) has moved its Chalkos project beyond visual indications and into laboratory-confirmed discovery territory, with both maiden holes at the Otniel prospect returning broad copper-silver intersections. DDOT001 delivered 37.1 metres at 1.23% copper and 15.2 grams per tonne silver from 54 metres down-hole, while DDOT002 returned 48 metres at 1.02% copper and 12.9g/t silver from 46 metres.
The stronger portions are substantial rather than isolated specks. DDOT001 included 6.62 metres at 3.05% copper and 40.0g/t silver, including a one-metre sample grading 5.12% copper and 86g/t silver. DDOT002 produced 7.15 metres at 2.76% copper and 34.6g/t silver, including a 1.1-metre sample at 6.42% copper and 61g/t silver.
The results provide the laboratory answer to the first two holes’ visible copper, which had previously indicated extensive mineralisation but left its commercial grade uncertain. Kaoko says the reportable intervals are narrower than the visible copper envelopes because they were calculated using a nominal 0.2% copper cut-off.
Silver tracks copper through the mineralised zones
Silver is not appearing as a detached bonus mineral in these early holes. Kaoko reports copper-silver correlation coefficients of 0.88 in DDOT001 and 0.92 in DDOT002, with the highest silver values coinciding with the highest copper grades. Silver also fell to detection or below detection beneath the copper zones.
The company interprets that consistency as evidence that copper and silver were deposited together in a sediment-hosted system. That remains an interpretation rather than a resource conclusion, and the two holes are not sufficient to establish a Mineral Resource. The reported lengths are down-hole measurements; true widths and the orientation of the mineralisation are not yet known.
Drilling expands across Otniel and Donkey Hill
Kaoko is now running two rigs across Chalkos, with drilling continuing at Otniel and a second rig advancing hole DDDH001 at Donkey Hill. The company had already expanded the program to at least 15,000 metres after early observations and a surface copper trend extending more than 700 metres at Donkey Hill East, a decision covered in the expanded Chalkos drilling program.
At Donkey Hill, the current drilling is designed to test the depth and continuity of surface copper occurrences across a footprint reported at more than 1.5km². Selected historical surface samples reached up to 69.6% copper at Donkey Hill, although surface sample grades cannot be treated as representative of the underlying mineralised system without drilling and further work.
Geology offers a targeting framework, not yet a mine plan
The assays point to a possible structural and chemical control on mineralisation. Stronger copper is associated with sheared or mylonitised rock, while an iron-rich footwall unit forms a sharp lower boundary in both holes. Lead is elevated above the copper zone and falls to background in the footwall, a pattern Kaoko says may help guide future drilling.
The company plans further petrography, spectral logging, sequential copper analysis and total sulphur work to identify the copper minerals and assess their metallurgical significance. Drone-based magnetic surveys and ground induced-polarisation surveys are also scheduled, while the broader diamond program will test scale, geometry and continuity. Renewal applications for the two Chalkos exploration licences have been submitted to Namibia’s Ministry of Mines and Energy, with processing still pending.
Bottom Line?
The first assays are a strong technical start, but the investment case now depends on whether follow-up drilling converts two promising intersections into a continuous, correctly oriented and metallurgically workable system.
Questions in the middle?
- Will step-out drilling establish true widths and continuity beyond the first two Otniel holes?
- Will assays from DDOT003 to DDOT006 and ongoing Donkey Hill drilling repeat the copper-silver grades?
- What will mineralogical and metallurgical studies reveal about the oxide or silicate copper identified in the early core?