Key highlights

• Fortuna Metals has reported aircore drilling results from the Kahuna prospect at its Mkanda Project in Malawi.

• The results show rutile mineralisation below the base of the existing inferred resource, announced to the ASX on 2 November.

• This update explains rutile, aircore drilling in soft-rock deposits, and the resource implications for the project.

Fortuna Metals (ASX:FUN) has reported aircore drilling results from the Kahuna prospect at its Mkanda Project in Malawi that show rutile mineralisation below the base of the existing inferred resource. The company announced the results to the ASX on 2 November, describing them as exceptional.

Notable intervals included 24 metres at 1.27% rutile, 24 metres at 1.22% and 24 metres at 1.12%, all from surface to the end of hole. Mineralisation remains open to the north and south, with further assays pending across the roughly two-kilometre Kahuna prospect.

Why depth is the key

The answer to the headline question is that the current resource, of about 300 million tonnes, is limited to the top eight metres. The new holes show rutile continuing to 24 metres, and the intervals ended in mineralisation. If that holds across the prospect, the Volume of mineralised material could be considerably larger than the current estimate assumes.

That is still a hypothesis. Three holes do not define a resource, and continuity between holes and across the full depth must be demonstrated. Grades may also vary with depth.

What rutile is and why it matters

Rutile is a naturally occurring form of titanium dioxide. It is used to make titanium pigment for paints and plastics, and titanium metal for aerospace and medical applications. Natural rutile is generally higher in titanium dioxide content than ilmenite, and therefore commands a premium.

Malawi has become an important destination for rutile exploration. Sovereign Metals' Kasiya project, also in Malawi, has drawn significant attention as a large rutile and graphite development, which provides useful context for the region's potential, although each deposit differs in grade, mineralogy and logistics.

Aircore drilling and soft-rock deposits

Aircore drilling is commonly used for soft, weathered material such as the saprolite that often hosts residual rutile deposits. It is relatively fast and low cost, making it well suited to defining broad, shallow mineralisation. Its samples can be less precise than diamond core, so resource estimates usually rely on a mix of methods and quality-control checks.

More results to come

Assays for drilling at the Agogo prospect are being processed, along with more than 2,700 samples from this year's drilling. That pipeline should provide a fuller picture of Mkanda's potential in coming months.

Economic considerations

Grade alone does not determine value for rutile deposits. Recoveries, the amount of clay and other minerals, the ease of Mining and processing, and the cost of transporting product to port all matter. Malawi is landlocked, so logistics to export terminals in neighbouring countries can be a significant cost.

Company context

The company held its Annual General Meeting in late October, according to ASX records.

Why it matters

Expanding a resource by extending it at depth can be cost-effective, because the surface footprint is already known. If the deeper material proves consistent, Fortuna could report a substantially larger resource in a future update.

What to watch

Investors may watch for remaining Kahuna assays, Agogo results, the processing of the 2,700-plus samples and any resource update.

Resource implications in simple terms

If a deposit is assumed to be eight metres thick and later proves to be 24 metres thick over the same area, the volume of material could, in theory, triple. In practice, resource growth is rarely that simple, because thickness, grade and density vary, and some deeper material may be harder to process. Fortuna will need enough holes across Kahuna to model the deeper zone with confidence. The pending assays, and any decision to drill deeper holes that pass fully through the mineralised profile, will show how much of that theoretical upside is real. That work will take time.