The quest for more feedstock to boost Western Australia’s Mid-West iron ore sector intensified during the March quarter when an ASX-listed junior confirmed it had established an “inaugural resource estimation” for a deposit it is now looking to turn into an open-pit operation.
Perth-based Tempest Minerals Ltd announced it had confirmed an inferred resource of 63.5 million tonnes of (dry) magnetite material grading 30.6 per cent iron at its Remorse play, which makes up part of the company’s flagship Yalgoo project.
Located around 215 kilometres south east of Geraldton on the eastern side of the targeted area in the Warriedar Fold Belt within the Yalgoo-Singleton Greenstone Belt of the Murchison region, the ore body was discovered in 2024 through the drilling of a volcanic massive sulphide-style base metals prospect.
While copper was intercepted, and considerable base metal potential remains in the mineralisation, the initial 4005 metre RC field program also intersected significant magnetite zones yielding iron grades of up to 39 per cent.
The company subsequently released an exploration target for the deposit and started other activities such as metallurgical testwork.
In addition, it signed a memorandum of understanding with burgeoning Mid-West steel developer GreenSteel and Iron Pty Ltd to assess the potential processing synergies which may exist between the two companies.
Geologically, the signs look promising for Tempest. Aside from the fact minimal regolith covers Remorse, the iron formations crop out as distinctive low, parallel, continuous ridges.
These outcrops are siliceous in the thin (less than 1m) zone and become fresh, consistent, hard, medium-grained magnetite-rich rock in the sub-surface (to around 150m).
Meanwhile, country rock consists of metamorphosed mafic and mafic-sedimentary lithologies.
Tempest said the resource modelling and estimation parameters were tailored to reflect a conventional open-pit scenario.
This included considerations of conservative cut-off grades based on typical regional pit assumptions.
“The inaugural resource matches well when compared to the previously released exploration target of the Remorse deposit, and provides excellent context for the current resources figures,” the company said in its March quarterly.
“This distinction reflects the transition from a more conceptually designed exploration target to a more detailed resource, based on verified geological and drilling information.”
Moreover, there was potential for extensional growth to the resource base as it was also noted that the current estimate was determined with relatively limited drilling, thus “further enhancing the project’s economic potential”.
This included extensional drilling along the known outcropping footprint, as well as the testing of undrilled units (at least five) that were not examined during the first program, and therefore not included in the current resource estimation.
“The initial resource estimate confirms the company’s belief that the Remorse deposit has high potential to be rapidly developed into a low cost, from surface, open-pit operation with major infrastructure including rail to port as well as multiple processing options available within short haulage distance,” Tempest said.
