Greatland Resources Limited

E: [email protected]

W: https://greatland.com.au

 NEWS RELEASE | 11 May 2026

Step-out drilling hits 58.7m @ 6.5g/t gold & 0.1% copper at Pinnacles prospect 1.2km south of the West Dome Underground resource, indicates extension of geological structure and stratigraphy

Highlights

·      1,858m exploration diamond drill hole (WRC14503A) 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. Assay results include the following significant intercepts:

·      58.7m @ 6.5g/t Au & 0.1% Cu from 1,754m (approximately true width), including:

·      37.0m @ 9.98g/t Au & 0.14% Cu from 1,754m (approximately true width); and

·      34.1m @ 1.1g/t Au from 1,820m.

·      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.

Greatland Managing Director, Shaun Day, commented:

"It is a credit to our Exploration team to have first interpreted the potential extension of the West Dome Underground at Pinnacles, a significant distance from our current area of focus, and then to successfully plan and execute this drill hole from surface to its target at depth.

"The wide high-grade mineralisation, including 58.7m @ 6.5g/t gold & 0.1% copper (381.6 gram-metres gold), is among the best intercepts achieved from West Dome Underground drilling to date.

"While the result is a single drill hole, it demonstrates the potential extension of West Dome Underground mineralisation to the south of our current resource. This new intercept is in similar proximity to our existing underground crusher and hoist infrastructure as the current West Dome Underground resource, further adding to its prospectivity.

"Further drilling will now be planned to test the existence and tenor of mineralisation between the two zones."

Overview of the West Dome Underground projects

Greatland Resources Limited (Greatland or Company) (ASX:GGP, AIM:GGP) is pleased to provide this exploration update on the West Dome Underground (WDU) project.

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 (Figure 1), 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 CY2025 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 WDU¹, 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) (Figure 2).

Note 1: Refer to Greatland's 30 March 2026 announcement titled 'December 2025 Group Mineral Resource Statement'.

Figure 1: Telfer December 2025 Mineral Resource schematic, showing location of Pinnacles drill hole and closest historical intercepts.

Figure 2: West Dome Underground December 2025 Mineral Resource isometric view.

Pinnacles prospect

The Pinnacles prospect is located approximately 1km south of the West Dome Open Pit and 1.2km south of the current WDU resource.²

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 (Figures 3, 5).

Note 2: Drilling was described in Greatland's 22 January 2026 announcement titled 'December 2025 Quarter Resource Development & Exploration Activities Report'.

Figure 3: Core photos of top of mineralised section from 1,757.75m downhole to 1,782.2m showing the massive sulphide zone (red line) and the stockwork mineralisation in sediments (blue line). Core is laid out top to bottom then left to right.

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 (gm) ³) 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.

Note 3: Formula: gm = interval width multiplied by Au grade.

Figure 4: Pinnacles drilling location with respect to existing WDU resource and underground infrastructure - isometric view looking NNW.

Figure 5: Pinnacles hole WRC15403A showing intercepts and Telfer shaft on interpreted geology with LLU in orange (200m+/- clip).

Proximity to existing underground infrastructure

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 (Figure 4).

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.

Next steps

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.

Further surface drilling to infill the 1.2km strike length between Pinnacles and the current WDU resource, to confirm the existence and tenor of mineralisation between these zones and potentially enable extension of the WDU resource, is also being considered, as is the potential for an underground drill out of this zone.

This announcement is approved for release by Shaun Day, Greatland's Managing Director.

Contact

For further information, please contact:

Greatland Resources Limited

Shaun Day, Managing Director  |  Andrew Bowler, Head of Investor Relations

[email protected]

Nominated Advisor

SPARK Advisory Partners

Andrew Emmott / James Keeshan / Neil Baldwin  |  +44 203 368 3550

Corporate Brokers

Canaccord Genuity  |  James Asensio / George Grainger  |  +44 207 523 8000

RBC Capital Markets  |  James Agnew / Jamil Miah  |  Scott Redwood  |  +44 207 029 0528

Media Relations

Australia - Fivemark Partners  |  Michael Vaughan  |  +61 422 602 720

About Greatland

Greatland is a gold and copper mining company listed on the Australian Securities Exchange and London Stock Exchange's AIM Market (AIM:GGP, ASX:GGP), and operates its business from Western Australia.

The Greatland portfolio includes the 100% owned Telfer mine, the adjacent 100% owned brownfield world-class Havieron gold-copper development project, and a significant exploration portfolio within the surrounding region. The combination of Telfer and Havieron provides for a substantial and long-life gold-copper operation in the Paterson Province in the East Pilbara region of Western Australia.

Forward-Looking Statements

This document includes forward-looking statements and forward-looking information within the meaning of securities laws of applicable jurisdictions. Forward-looking statements can generally be identified by the use of words such as "may", "will", "expect", "intend", "plan", "estimate", "anticipate", "believe", "continue", "objectives", "targets", "outlook" and "guidance", or other similar words and may include, without limitation, statements regarding estimated reserves and resources, certain plans, strategies, aspirations and objectives of management, anticipated production, study or construction dates, expected costs, cash flow or production outputs and anticipated productive lives of projects and mines.

These forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause actual results, performance and achievements or industry results to differ materially from any future results, performance or achievements, or industry results, expressed or implied by these forward-looking statements. Relevant factors may include, but are not limited to, changes in commodity prices, foreign exchange fluctuations and general economic conditions, increased costs and demand for production inputs, the speculative nature of exploration and project development, including the risks of obtaining necessary licences and permits and diminishing quantities or grades of reserves, political and social risks, changes to the regulatory framework within which Greatland operates or may in the future operate, environmental conditions including extreme weather conditions, recruitment and retention of personnel, industrial relations issues and litigation.

Forward-looking statements are based on assumptions as to the financial, market, regulatory and other relevant environments that will exist and affect Greatland's business and operations in the future. Greatland does not give any assurance that the assumptions will prove to be correct. There may be other factors that could cause actual results or events not to be as anticipated, and many events are beyond the reasonable control of Greatland. Forward-looking statements in this document speak only at the date of issue. Greatland does not undertake any obligation to update or revise any of the forward-looking statements or to advise of any change in assumptions on which any such statement is based.

Competent Persons Statement

Information in this announcement pertaining to exploration results is based on, and fairly represents, information and supporting documentation compiled by and approved by Mr Damien Stephens, a Member of the Australian Institute of Mining and Metallurgy (AusIMM), who has more than 30 years relevant industry experience. Mr Stephens, an employee of the Company, has sufficient experience relevant to the style of mineralisation, type of deposit under consideration, and to the activity which he is undertaking to qualify as a Competent Person as defined by the 2012 Edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (the JORC Code) and under the AIM Rules - Note for Mining and Oil & Gas Companies, which outline standards of disclosure for mineral projects. Mr Stephens consents to the inclusion in this announcement of the exploration results and the supporting information in the form and context in which they are presented. 

This announcement contains references to Mineral Resource estimates for Telfer, which have been extracted from the Company's ASX announcement dated 30 March 2026 titled 'December 2025 Group Mineral Resource Statement'. The Company confirms that it is not aware of any new information or data that materially affects the information included in those announcements, and in the case of the estimates of Mineral Resource and Ore Reserve, that all material assumptions and technical parameters underpinning each of the estimates in the relevant ASX announcement continue to apply and have not materially changed.

Drillhole Data and Au-Cu Significant Intersections

Significant assay intercepts are reported as length-weighted averages in Table 1 and Table 2. Intervals less than 10 Au gram metres and those with <1 g/t Au average grade have not been included.

All Telfer exploration primary intervals are calculated at 0.2g/t Au cut-off and minimum 0.1m downhole width with 5m maximum consecutive internal dilution.

Table 1: Significant intercepts & drilling data (Telfer Mine Grid).

Table 2: Historical intercepts & drilling data (Telfer Mine Grid).

JORC 2012 Table 1: Section 1 - Sampling Techniques and Data

JORC 2012 Table 1: Section 2- Reporting of Exploration Results