Solstice Minerals: 722m Nanadie Intercept and What It Signals

Drilling at a copper-gold exploration project in the Western Australian Goldfields.

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By Charles Pitts

Solstice Minerals’ latest Nanadie result changes the scale of the exploration question.

Hole NANRCD005 returned a combined 722.3 metres at 0.44% copper and 0.13 g/t gold, extending mineralisation more than 500 metres below the company’s current 40.4-million-tonne inferred Mineral Resource Estimate. The result does not, by itself, establish an updated resource or a mine plan. It does, however, show that the mineralised system continues well beyond the depth envelope that currently supports the resource.

That distinction matters. Nanadie is no longer being tested only as a near-surface resource expansion opportunity. Solstice’s drilling is beginning to examine whether the project hosts a much larger, vertically extensive copper-gold system, with higher-grade zones developing within a broad mineralised envelope.

The figures and drill programme details discussed below are attributed to Solstice Minerals company reporting, as summarised in the company announcement coverage published by Kalkine.

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What NANRCD005 actually tested

NANRCD005 was drilled as a diamond tail to the Phase 1 reverse-circulation hole NANRC005. The diamond portion began at 324.3 metres and continued to a final depth of 840.6 metres.

The headline 722.3-metre interval runs from the margin of the granite to the end of the hole. It combines the RC and diamond sections and includes internal unmineralised intervals. That makes it a broad system-scale intercept rather than a narrow composite designed to isolate only the strongest mineralisation.

This is important when interpreting the result. The average grade of 0.44% copper and 0.13 g/t gold describes a long mineralised and altered zone, but it does not mean every metre carried those grades. The value of the hole lies in the combination of:

• The length of the mineralised envelope.
• Its continuity to more than 700 metres below surface.
• The presence of repeated higher-grade sub-intervals.
• The fact that the system remains open beyond the current drilling.

Solstice describes the mineralisation as occurring within altered gabbro and dolerite, with chalcopyrite present as disseminations, fabric-parallel veinlets and cross-cutting sulphide veins. Later felsic and mafic dykes appear to separate some mineralised zones.

Exploration drilling pads aligned along the Nanadie mineralised trend.

The higher-grade zones inside the long intercept

The broader interval is supported by several materially stronger sections. Solstice reported the following results from the diamond tail:

The distribution is as significant as the individual grades. Higher-grade sections appear at several depths rather than being confined to a single isolated interval. The strongest reported sub-interval, 8 metres at 1.49% copper and 0.86 g/t gold from 794 metres, occurs near the bottom of the hole.

That does not prove the grade strengthens at depth across the wider system. One hole is insufficient to establish a trend. It does indicate that the deeper part of Nanadie is not simply a low-grade continuation of the shallower resource envelope.

The company has also said that NANRCD004 and NANRCD005 are helping define a potentially higher-grade position along the eastern margin of the host gabbro. This eastern corridor is becoming a central focus for further drilling and future resource modelling.

Why the 500-metre extension matters

Nanadie’s current inferred resource is reported at 40.4Mt grading 0.4% copper and 0.1 g/t gold, containing approximately 162,000 tonnes of copper and 130,000 ounces of gold.

NANRCD005 extends mineralisation more than 500 metres below the boundary of that estimate. In practical terms, the hole demonstrates that the present resource boundary is an envelope of geological confidence, not necessarily the bottom of the mineralised system.

For operators and technical teams, the next question is whether this deeper mineralisation can be:

1. Correlated between multiple drill sections.
2. Modelled with sufficient geological and assay confidence.
3. Tested for continuity along strike and across the host rock.
4. Incorporated into a future resource estimate under appropriate classification rules.
5. Evaluated for metallurgical and mining relevance.

The depth extension may eventually increase the volume of mineralised rock. It could also complicate the development concept if the strongest material sits substantially deeper than the current resource. More tonnes are not automatically equivalent to a lower-cost or simpler project. Depth, geometry, recovery, dilution, mining method and infrastructure requirements will all influence the eventual economic interpretation.

A system at least 1.2 kilometres long: and still open

Solstice currently defines the Nanadie mineralised system over at least 1.2 kilometres of strike, with an estimated width of approximately 100 to 200 metres. The company reports that the system remains open to the north, south and at depth.

The strike dimension is important because it gives the project multiple avenues for growth. Deeper drilling can test vertical continuity, while step-out holes may determine whether the known mineralisation continues beyond the current drillout.

The company’s drilling plan includes:

• Step-out strike traverses.
• Mineral Resource Estimate delineation holes.
• Step-down exploration holes.
• Diamond tails targeting deeper portions of the system.
• Short-hole reverse-circulation drilling at the nearby Stark prospect.
• Testing of geophysical targets and unexplored strike positions.

Solstice has also indicated that a second RC rig is due on site. That should allow the company to increase drill coverage, although the pace of results will still depend on drilling conditions, sample processing, laboratory turnaround and geological interpretation.

Diamond core logging can help define alteration, sulphide textures and geological continuity.

What drilling results are still pending

The next phase of interpretation will depend heavily on results that have not yet been released. Solstice has reported assays pending from 14 completed diamond holes and more than 20 RC holes.

Those assays should help answer several questions:

• Does the deeper mineralisation continue across adjacent sections?
• Are the higher-grade eastern-margin zones consistent from hole to hole?
• Does the system maintain its width outside the existing resource envelope?
• Do northern and southern step-outs extend the 1.2-kilometre strike?
• Are the deeper zones structurally controlled or broadly disseminated?
• How much of the mineralisation can be converted from exploration potential into resource confidence?

The company has also said that no blank hole has been drilled across the more than 1.2-kilometre drillout to date. That observation supports continuity of the mineralised trend, but it should not be confused with a formal resource estimate. A continuous run of mineralised holes still requires detailed geological modelling, density data, quality assurance and quality control, and appropriate estimation parameters.

Readers tracking the broader copper market can place Nanadie in the context of Skillings’ copper price outlook, while the project’s exploration significance aligns with the themes covered in Skillings Mining Intelligence’s copper and M&A analysis.

What to watch before any resource update

A future resource update should be assessed against more than the headline metres and grades. The most useful indicators will be:

1. Drill spacing: Are the new holes close enough to support a confident geological interpretation?
2. Continuity: Do the higher-grade zones persist along strike and down dip?
3. Geometry: Is the mineralisation broad and coherent, or made up of separated lenses?
4. Grade distribution: Does the deeper extension add consistent copper-gold content or mainly low-grade volume?
5. Metallurgy: Can the disseminated and vein-style chalcopyrite produce a saleable concentrate at acceptable recoveries?
6. Density and rock strength: Do deeper fresh-rock conditions change the volume estimate or potential mining approach?
7. Classification: How much of any expanded estimate can be reported as inferred, indicated or measured material?

The eventual resource outcome will therefore be a technical test of continuity and confidence, not simply an arithmetic extension of the 40.4Mt estimate.

Key risks

Assay and geological risk

The 722.3-metre figure comes from one deep hole and includes unmineralised intervals. Further drilling may show that the strongest zones are narrower, discontinuous or structurally restricted.

Depth and mining risk

Mineralisation below the current resource boundary may add tonnes but could be more difficult or costly to access. Any development assessment would need to consider depth, strip ratio, underground access, haulage and mine sequencing.

Metallurgical risk

Visible chalcopyrite and broad sulphide zones are encouraging geological observations, but they do not establish recovery rates, concentrate quality or processing costs. Sighter metallurgical work remains important.

Resource-estimation risk

A new resource estimate requires validated assays, density measurements, geological domaining, appropriate interpolation and compliance with reporting standards. The timing and scale of any update remain uncertain.

Exploration and execution risk

The expanded drilling programme will require rigs, camp capacity, sample processing and laboratory availability. Delays or inconsistent drilling results could slow the conversion of exploration success into a more reliable resource model.

A quotable framework for interpreting Nanadie

Nanadie’s 722-metre result should be read as a scale signal first, a grade signal second, and a development signal only later.

That framework separates three stages of analysis:

• Scale: NANRCD005 shows that mineralisation continues more than 500 metres below the current resource boundary and remains open at depth.
• Grade: Multiple internal zones carry around 1% copper or more, including a high-grade section near the bottom of the hole.
• Development: The project still requires further drilling, metallurgical work and resource modelling before its economic potential can be assessed.

The immediate significance of NANRCD005 is that Nanadie is becoming a larger and more vertically extensive exploration system than the existing resource captures. The next test is whether pending assays and follow-up drilling can turn that geological scale into repeatable continuity, stronger resource confidence and a coherent project model.