Announcement • May 11

Greatland Resources Limited Provides Exploration Update for West Dome Underground

Greatland Resources Limited announced that a 1,858m exploration diamond drill hole (WRC14503A) was recently drilled from surface at the Pinnacles prospect, to test potential extension of the geological structures and stratigraphy that host the West Dome Underground (WDU) deposit, approximately 1.2km to the south of the current WDU Mineral Resource Estimate (MRE). The Pinnacles drill hole intersected high grade mineralisation and indicates a significant extension of the West Dome geological structure. The mineralisation is open to the north towards the WDU, and to the south, which is entirely untested. Further drilling is required to confirm the tenor and extent of the mineralisation between the WDU and the Pinnacles intersection, as well as to the south. This new intercept is situated approximately 1.5km from the existing Telfer underground crusher and hoist infrastructure. Follow-up work to be completed includes: Wedge holes from drill hole WRC14503A, to test mineralisation between 50-100m along strike and down dip. Planning for drilling between Pinnacles and WDU, and extension drilling further south of Pinnacles. The WDU emerged from the recognition that key geological structures hosting mineralisation in the Main Dome Open Pit repeat in the West Dome Open Pit. Accordingly, it was proposed that the geological features that are key to mineralisation in the Main Dome Underground may repeat below the West Dome Open Pit. The WDU was a high priority target identified by Greatland's due diligence prior to the acquisition of Telfer. Following completion of the acquisition, Greatland accelerated drilling in Calendar Year 2025 from newly established underground positions, with a total of 18,963m drilled to December 2025. Greatland's drilling has confirmed that the key geological units hosting the Main Dome Underground mineralisation are present in the WDU. On 30 March 2026, Greatland announced a maiden Mineral Resource Estimate (MRE) for WDU, comprising 8.0Mt @ 2.30g/t Au & 0.44% Cu for 0.6Moz Au & 35Kt Cu. The WDU MRE is contained within an anticline hinge and hosted across two key domains: the high-grade sulphide replacement Lower Limey Unit (LLU) and the broad mineralised Western Stockwork Corridor (WSC). The Pinnacles prospect is located approximately 1km south of the West Dome Open Pit and 1.2km south of the current WDU resource. Utilising the strong understanding of the Telfer geological structures and stratigraphy from both the recent WDU drilling and historical shallower drilling between the current WDU resource and the Pinnacles prospect, a 1.8km diamond drilling (DD) drill hole was commenced from surface, targeting the West Dome anticline hinge within the LLU stratigraphic layer. This target was interpreted to lie approximately 1,750m downhole. Drilling of diamond hole WRC14503A commenced in December 2025 and reached the target depth in April 2026. Massive pyrite with ancillary chalcopyrite and quartz veining, likely replacing the LLU, were intersected from 1,758m downhole and extended to 1,772m, with interbedded sediments, quartz breccias and narrow massive sulphides to 1,792m. Stockwork quartz veining and sulphides continue to end of hole at 1,858m, and also occur 4m above the LLU contact, commencing at 1,754m. The massive sulphide and interbedded sediments zone to 1,792m is interpreted to correlate to the WDU LLU strata bound orebody containing the majority of the current WDU resource. The stockwork breccia is similarly considered to be the WDU vertical WSC in the core of the WDU anticline hinge below the LLU. This interpretation is supported by the target stratigraphy and structure being intersected within approximately 10m of its predicted down plunge location, 1,200m down plunge of the current WDU resource. Further evidence of the extension of the West Dome structure is from the existence of several narrow reef style veins at around 1,640m downhole in the Middle Malu formation above the LLU, which are of similar style to the A-reef's at Main and West Dome. The intercept of 58.7m @ 6.5g/t Au & 0.1% Cu (381.6 gram-metres Au) from 1,754m includes 37m @ 9.98g/t Au & 0.14% Cu from 1,754m, which approximates to the LLU with the massive sulphide identified in the core. These assays are considered to be dominantly stratabound and were intersected by the drill hole at a high angle to bedding, making them close to true width intersections of the mineralisation. A further intercept of 34.1m @ 1.1g/t Au (37.5 gm Au) from 1,820m extends below the LLU, within the lower interpreted vertical stockwork corridor, and weak mineralisation extends further to the end of hole. While this result indicates the extension of the structure and geology from the WDU to the Pinnacles prospect, further drilling will be required to confirm the existence and tenor of mineralisation between the two zones. The Main Dome Underground (MDU) is situated below the Main Dome Open Pit, and to date has mined over 75Mt of ore, for more than 3.1Moz gold and 210kt copper. The MDU crusher and hoist to surface is located at a depth of approximately 1,000m below surface and is approximately 1.5km north-east of the Pinnacles mineralisation, which is similar to the distance between the current WDU resource and the crusher and hoist. The underground crusher and hoist provide an efficient and low-cost materials handling system that transports ore from the underground crusher to surface and is then directly conveyed into train 1 of the Telfer processing plant. This underground materials handling system has a capacity of approximately 6Mtpa and has been in continuous use since its completion in 2007. Currently the Main Dome Underground is operating at a mining rate of approximately 1.2Mtpa. Accordingly, there is significant latent infrastructure capacity at the MDU to support potential mining operations at WDU, including: ~6Mtpa crushing and hoist haulage capacity via the existing shaft; water pumping infrastructure with installed capacity of 132L/s, with current mining activities in the MDU utilising on average 50L/s; ventilation infrastructure designed for approximately 5Mtpa SLC, currently operating as a ~1.2Mtpa stoping operations; electricity generation from the Telfer power plant and transmission via the MDU; and a paste plant. Planning is underway to complete at least three wedges off hole WRC14503A with the aim of gaining 50-100m of separation of intercepts along strike both north and south (Mine Grid) and down dip within the LLU massive sulphide.

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