OUR PROJECTS / GREENVALE Project

Steam Engine

Steam Engine, situated 210 km west of Townsville in northeast Queensland, is recognised for its high-grade gold lode and ore shoot system. The project is part of Superior's 100%-owned Greenvale Project and is located between several Tier 1-potential porphyry Cu-Au-Mo prospects and a magmatic sulphide Ni-Cu-PGE province.

Comprising several lode systems including the Steam Engine Lode and Eastern Ridge Lode, the project spans a considerable strike length, showcasing multiple gold-bearing zones within shear zones characterised by pyrite-quartz-muscovite-carbonate schist. Gold mineralisation occurs within north-northeast trending, west-dipping lodes hosted by metamorphosed intermediate to basic intrusives and metasediments.

Feasibility Study
- A Feasibility Study is progressing in order to progress the project to development as an initial Haulage and Toll Treatment operation.

Scoping Study
- A 2024 Scoping Study based on an assumed gold price of A$3,250/oz indicated robust economics for both a Toll Treatment scenario and On-Site Processing scenario.

Mineral Resource Estimate
- The Steam Engine Project saw a significant revision in its Mineral Resource estimate in 2022, with up to 196,000 oz of gold at a grade of 1.5 g/t Au, encompassing Measured, Indicated, and Inferred JORC (2012) categories under an On-site Processing Model. This update reflects the inclusion of extensive drilling data and underscores the project’s robust potential.
  - Measured: 800,000 tonnes @ 2.1 g/t Au (53,000 ounces)
  - Indicated: 1,420,000 tonnes @ 1.5 g/t Au (68,000 ounces)
  - Inferred: 1,960,000 tonnes @ 1.2 g/t Au (75,000 ounces)
  - Total: 4,180,000 tonnes @ 1.5 g/t Au (196,000 ounces)
  - Under the Toll Treatment Model, the estimates are adjusted to higher cut-off grades resulting in a total of 2.72 Mt at 2.0 g/t for 171,000 ounces Au.

2024 Resource Drilling Program / MRE Upgrade
- A Resource expansion drilling program identified multi-lode extensions to the Steam Engine and Eastern Ridge lodes.
- The Mineral Resource Estimate will be revised after receipt of drill hole assays.

Potential to Increase Total Mineral Resources
- The Steam Engine Project harbours significant potential for expanding its gold resource inventory, with current resources developed to a relatively shallow depth of less than 100 metres and along 1.3 km of total potential lode strike length. Recent studies have identified at least 10 km of additional lode potential along known structures, promising substantial growth in the project’s resource base.

Additional Highlights:
- High-grade intersections have been reported, including 5m @ 38g/t Au from 49m (including 1m @ 184g/t Au) and 7m @ 20.6g/t Au from 54m (including 1m @ 135g/t Au).
- A recent Sub-Audio Magnetics (SAM) survey has highlighted a potential southern extension of the Steam Engine Lode and several previously unknown potential lode zones.
- Metallurgical test work has shown average recoveries of 82% for the Steam Engine Lode and 95% for the Eastern Ridge Lode.
- An audit conducted by CSA Global Mining Industry Consultants in July-August 2023 considered the Steam Engine block models to be reasonable global estimates.

Steam Engine, Eastern Ridge and Southern Zone lodes over soil gold anomalies and conceptual corridors for high-grade ore shoots

Revised Scoping Study – September 2024

An earlier Scoping Study was completed in 2021 – on the basis of toll treatment only. This 2024 Scoping Study is fundamentally different to the 2021 study.

The revised Scoping Study confirms a financially and technically robust opportunity to develop the Project as a low CAPEX open pit mining and toll treatment operation and also highlights robust economics for a stand-alone on-site processing plant operation, albeit with higher capital cost requirements.

Table 1 summarises the physical and financial evaluation of a Toll Treatment scenario and a Stand-Alone Processing Plant scenario based on the mining of 863k tonnes of ore at 2.34g/t Au to recover ≈55,000 ounces of gold (Toll Treatment scenario) and 2.13 million tonnes of ore at 1.53g/t Au to recover ≈89,000 ounces of gold (Stand-Alone Processing). The modelled production figures represent approximately 32% and 45% of the Total Mineral Resources for the Toll Treatment and Stand-Alone Processing scenarios, respectively.

All financial results are approximated in accordance with Scoping Study parameters and are provided in Australian dollars unless stated otherwise.

TABLE 1