Sunstone Metals Annual Report 2026

Overview Operating Review continued Six domains were identified as having clear potential for additional mineralisation and these were reviewed either on a depth slice basis, or a block basis. Volumes were calculated and grade was assigned based on nearby data and on comparison with the overall Brama-Alba grade. The Melonal target is a continuation of the Brama-Alba system. It is geologically grouped with Brama-Alba. Recent drilling by Sunstone, and historical drilling from 2007, has confirmed that the Melonal target is mineralised, and that mineralisation is hosted in rocks the same as those drilled at the nearby Brama-Alba deposit. The mineralised rocks are coincident with a discrete sub-vertical magnetic anomaly measuring up to 400m in diameter, and with a vertical extent of over 1,000m. The Exploration Target for Melonal was considered to a depth of 500m. The Melonal target straddles the approved Bramaderos-01 and Bramaderos-02 concessions. Sunstone has drilled 8 effective diamond holes at the Limon porphyry target. Mineralisation has been intersected in a number of holes. A trench (LM_ TR_01) was completed at Limon prior to drilling in an area of outcropping stockwork veining and minor secondary copper mineralisation. It returned 97m at 0.73g/t gold and 0.23% copper. A recent hole drilled under the trench has intersected similar stockwork veined intrusive and contains chalcopyrite. This area around Trench TR_LM_01 has been included in the porphyry Exploration Target where more drilling is required to allow inclusion in a Mineral Resource estimate. This target area will be further explored with drilling programs to be executed over the next two years, subject to the Company’s funding ability. Copete and Porotillo The Copete and Porotillo exploration targets are areas of outcropping porphyry stockwork veining that occur within an extensive gold and copper soil geochemical anomaly. These areas have seen substantial historical drilling (13 drill holes) with extensive mineralised intersections, plus widespread rockchip sampling of surface mineralisation, channel sampling in ravines and an extensive mineralised trench ML-01 at Copete that assayed 214m @ 0.50 g/t AuEq2 (ASX announcement 12 November 2024). At Porotillo, within the main body of the goldin-soil geochemical anomaly, an extensive earlymineral quartz diorite intrusion hosts overprinting porphyry-related, disseminated and vein stockwork mineralisation over an area spanning up to approximately 530m by 310m. Very substantial historic drill intersections were encountered at Porotillo. Two domains were modelled to generate the Copete-Porotillo exploration target to depths of 200m and 400m below surface. This target area will be further explored with drilling programs to be executed over the next two years, subject to the Company’s funding ability. Limon epithermal The Limon epithermal Exploration Target was estimated on target prospects where there was a combination of diamond drilling (by Sunstone), geological mapping, trenching, geochemistry (soils) and to a lesser extent geophysical data (magnetics) which could support the geological and mineralisation concept model. The Limon alteration area has been covered with soil sampling on a 50m x 50m grid. This survey is an important exploration method which identified several gold-in soil anomalies that are primary targets for drilling. The soil geochemical data is further interpreted using related element associations typical of epithermal systems, such as areas of somewhat coincident gold, silver, zinc, lead, copper, tellurium and arsenic. Target areas have also been strengthened using alteration mineralogy from a hand-held Terraspec instrument. These data assist in mapping the alteration zones most likely to be associated with epithermal mineralisation. Drilling at Limon has also intersected a high sulphidation system in holes LMDD004 and 006, which included intersections of 13.3m at 0.43% copper and 0.11g/t gold, within 59.6m at 0.16% copper. Standard geological mapping and rock chip sampling has also been undertaken across the Limon target area. The volume ranges for the initial Exploration Target in the Central Shoot were estimated using cross sections and 3-D modelling in Leapfrog software, based upon an analysis of drilling, mineralised rock types, grade distribution, potential for extrapolation of mineralisation continuity and interpreted geological risk. 22 Sunstone Metals Limited Annual Report 2026

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