Native Mineral Resources Holdings Limited announced that it is continuing to fast-track its targeting of IOCG-style mineralisation at its 100%-owned Helios Project, located in the Nullarbor region of Western Australia. NMR has engaged a third-party contractor to complete the gravity survey which is planned to begin this week. The results will be used to pinpoint the location of its second diamond drill hole in the area following the identification of IOCG-style hematite and magnetite alteration in drill hole HELIOS_DDH001.

The alternation identified to date has strong similarities to large IOCG systems such as the Ernest Henry deposit. As a result, NMR is now focused on locating the potential for copper and gold mineralisation associated with such alteration. As reported on 16th May 2022, NMR completed its maiden diamond drilling program at the Helios Project and intersected what the company considers to be significant IOCG-style alteration including felsic breccias with hematite, magnetite, and pervasive hematite alteration of host granites.

A common signature or "fingerprint" of IOCG systems is the close association between magnetic highs and gravity highs (e.g. Austin and Foss, 2012). Deposits such as Ernest Henry, Prominent Hill, and Brumby are examples where this correlation is observed. NMR is planning to complete the gravity survey to help delineate areas of increased density typically associated with mineralisation within these systems. Based on existing, low-resolution regional gravity data, the density anomaly may be at depth or along strike from the existing drill hole.

NMR has already completed a drone-based magnetics survey over the area prior to the drilling of HELIOS_DDH001. The magnetics data was fundamental to the planning of the drill hole as the modelling highlighted a target magnetic body with a susceptibility value of 0.17 SI units. Drilling did not reach a higher magnetic body (0.2 SI) modelled at slightly greater depths.

A combination of magnetics and gravity is considered by NMR as critical information to help refine and guide future drilling. The second diamond drill hole at Helios is supported by a $220,000 Exploration Incentive Scheme (EIS) grant. The key observations from recent drilling include: Felsic breccias are present throughout the drill core containing hematite alteration and both magnetite and hematite are present within the groundmass.

The felsic breccias cut across the altered igneous intrusives including diorite, and quartz-diorite host rocks. Magnetite is abundant (up to 10-12%) in the groundmass of the intrusive host rocks. increasing hematite alteration is present as red-staining of breccia fragments and host igneous minerals and/or disseminated clusters or disseminated groundmass in the host igneous rock.

Pyrite occurs as disseminated grains throughout the matrix or as small, centimeter-scale patches within the host igneous rock and within the hematite-dominated breccia matrix. The central magnetic anomaly at Helios is approximately 2 km long x 1 km wide, comparable in size to the magnetic anomaly associated with other IOCG deposits such as Ernest Henry. The identification of potential IOCG-style alteration is significant.

NMR has been unable to find any previous documentation of pervasive hematite alteration or indication of IOCG mineralisation in any other open-file drill reports for this area of the Nullarbor, therefore, this drill hole represents a major advance in the potential prospectivity of the region. Drill hole HELIOS_DDH001 intentionally targeted the upper 500m to test the basement for rock type and for the potential of mineralisation. The drilling successfully identified hematite and magnetite, which is likely to account for at least part of the magnetic anomaly observed at the surface.

Drilling did not extend into the C2 body which exhibits higher modelled magnetic susceptibility (0.2 SI). The intensity of alteration increases with depth. NMR will complete a second drill hole following the completion of the gravity survey and as part of the DMIRS-funded EIS grant.

Drilling has revealed that the rocks are indeed magnetite bearing as modelled, however, the alteration and results obtained are more indicative of the alteration style(s) associated with large IOCG systems like the Olympic Dam and Ernest Henry deposits. NMR will now focus its efforts on locating the potential copper and gold mineralisation associated with such alteration.