Heavy Rare Earths Expands South Ridge Tin Target to 1.85km

Heavy Rare Earths Ltd extends South Ridge tin target and confirms drilling approvals

Heavy Rare Earths Ltd (ASX: HRE) has reported that new surface geological mapping at the South Ridge tin prospect, part of the Prospect Hill Project in South Australia, has increased the mapped outcrop of the main South Ridge Shear zone to 1.85 kilometres. This Heavy Rare Earths South Ridge tin drilling approvals and 1.85km target expansion announcement confirms that all approvals are now in place for its maiden drilling program, which has been enlarged from 28 drill holes for 2,500 metres to up to 36 holes for 3,400 metres to allow collection of material for metallurgical test work.

According to the ASX announcement dated 9 July 2026, the updated survey has also identified multiple previously unmapped structures running parallel to the main shear zone. Heavy Rare Earths Ltd reports that these parallel features present additional exploration targets as the company advances towards a maiden Mineral Resource Estimate (MRE) at what it describes as South Australia's most advanced tin prospect.

A larger mineralised footprint at South Ridge

The survey work at South Ridge focused on extending and refining the understanding of the main mineralised structure and any repeat or related zones in its immediate vicinity.

Geologists from Heavy Rare Earths Ltd carried out detailed geological mapping and sampling, supported by field-based portable X-ray fluorescence (pXRF) testing. Traverses were made perpendicular to the interpreted strike of the South Ridge Shear zone to track any continuation of known structures.

Key outcomes from this work include:

• Total mapped outcrop of the main South Ridge Shear zone increased to 1.85 km
• The shear zone is reported to be up to 10 metres wide along its mapped length
• The western extent of the zone is truncated by a younger cross-cutting shear
• Shallow alluvial cover prevents direct surface tracing beyond this truncation, so the potential for an offset continuation remains
• Several parallel structures proximal to the main South Ridge Shear have been identified for the first time

According to the company, the combination of mapping and pXRF screening allowed efficient identification of zones displaying anomalous mineralisation signatures, even where visual tin mineralisation is limited or absent at surface.

CEO and Managing Director commentary
"As we approach HRE's maiden drilling program at South Australia's largest and most advanced Tin Project, South Ridge, at Prospect Hill, it is highly encouraging to report the detailed surface mapping program conducted by our field crews has demonstrated new extensions that now delineate a 1.85 km long mineralised structure. In addition, work has identified several parallel structures worthy of follow up, that indicates that South Ridge may not be an isolated structure. We now have all approvals for drilling following the approval of our PEPR, and we look forward to commencing an expanded program as soon as roads reopen," said Jason Barnett, Chief Executive Officer and Managing Director.

From an investor perspective, the extension of mapped strike length increases the scale of the tested target, while the newly identified parallel structures suggest a broader mineralised system rather than a single isolated lode. These additional structures will require further work, including continuous rock-chip sampling and potential drill testing, and may add new targets for future campaigns if follow-up assays confirm mineralisation.

Under-explored western zone with historical high-grade tin

The western portion of the South Ridge Shear zone is described in the announcement as significantly under-explored relative to the central part of the structure.

A review of historic exploration data by Heavy Rare Earths Ltd focused on this western segment and recorded:

• Only 7 drill holes completed across a 450-metre strike length in the western zone
• All 7 holes were drilled by Havilah Resources more than 9 years ago
• No follow-up drilling has been conducted on this part of the structure since those holes

Two of the historic holes intersected high-grade tin, reported as follows (referencing Havilah Resources ASX announcement dated 1 June 2017):

According to the announcement, these higher grade tin intersections occur beneath historic costeans (surface trenches) that contained the typical South Ridge lode mineral assemblages but only showed moderate to very weak anomalous tin in assays.

This contrast between weak surface anomalism and stronger grades at depth illustrates why Heavy Rare Earths Ltd is emphasising structural mapping and careful identification of lode positions at surface rather than relying solely on elevated tin values in shallow samples. It also means that a 900-metre zone in the western part of the shear is both relatively under-drilled and already supported by historical intersections that indicate the presence of high-grade tin at depth.

For investors, this under-tested western section represents a key focus area for the upcoming drill program. Furthermore, if the planned drilling confirms continuity or expansion of the mineralisation indicated by PHRC56 and PHRC59, this could be material to any future MRE.

Educational section: what shear zones mean for tin exploration

Understanding the concept of a shear zone is central to interpreting the significance of the South Ridge results reported by Heavy Rare Earths Ltd.

What is a shear zone?

A shear zone is a band of rock that has undergone intense deformation due to movement along a fault or major structural feature in the crust.

In simple terms:

• Rocks on either side of the zone have slid past each other under stress
• The rocks within the zone are often fractured, crushed or strongly deformed
• Fluids from within the Earth can move more easily through these zones

These circulating fluids can carry dissolved metals such as tin, gold, copper and other elements. When the chemical or physical conditions change, those metals may be deposited within the fractures and veins inside the shear zone.

At South Ridge:

• The shear zone is steeply dipping (near vertical)
• It has a mapped width of up to 10 metres
• It has a mapped strike length of 1.85 km

A long, steep, structurally continuous host such as this provides a physical setting where repeated pulses of mineral-bearing fluids may have deposited metal over geological time.

Why are shear zones important for investors?

From an investment perspective, shear zones are relevant for several reasons:

• Scale potential: A longer strike length provides more linear extent that can potentially host mineralisation. The 1.85 km at South Ridge defines a material exploration corridor for Heavy Rare Earths Ltd.
• Depth potential: Steeply dipping structures can often continue to depth, which may be important if any future mining concept considers underground extraction.
• Multiple lodes: The identification of parallel shear-related structures near the main zone suggests a structural corridor where several lodes could exist, not just one.

If systematic drilling confirms continuity of grade and thickness within such structures, they can underpin a future MRE. However, actual resource outcomes will depend on drill-supported geometry, grade distribution and tonnage, all of which remain subject to ongoing exploration and interpretation.

Key geological terms explained

To assist non-specialist readers, key terms used by Heavy Rare Earths Ltd can be summarised as follows:

• Strike length: The length of a rock unit or mineralised zone measured along its horizontal trend at surface.
• pXRF (portable X-ray fluorescence): A handheld device that uses X-rays to rapidly test rock chips for elements. At South Ridge it is used as a screening tool to detect zones with anomalous chemistry, not to generate final assay data.
• Costean: A shallow trench dug to expose bedrock for sampling and mapping.
• Reverse circulation (RC) drilling: A drilling method that recovers crushed rock chips for sampling using compressed air. It is widely used in exploration because it is relatively fast and cost-effective.
• Diamond drilling: A drilling method that produces a continuous intact core of rock. It is more expensive than RC but yields detailed structural information and is useful for metallurgical test work.
• Mineral Resource Estimate (MRE): A structured estimate of the size and grade of a mineral deposit prepared under codes such as the JORC Code. It is a key milestone for project assessment.

By applying these concepts to South Ridge, investors can place the work of Heavy Rare Earths Ltd in a clearer context.

All approvals in place and drill program expanded

Alongside the geological updates, Heavy Rare Earths Ltd has confirmed that all regulatory and heritage clearances required for the maiden drill program at South Ridge are now secured.

According to the announcement:

• Heritage clearance has been obtained from the Dieri Aboriginal Corporation
• A Program for Environment Protection and Rehabilitation (PEPR) has been approved by the South Australian Department of Mines and Energy (DEM)
• A drilling contract has been executed with a drilling contractor to carry out both RC and diamond drilling
• Camp sites for drilling and geological crews have been finalised at the base of South Ridge
• Collar pegs marking planned drill hole locations have been set on the ground

The company reports that it is now waiting for local roads to reopen to heavy vehicle traffic before mobilising earthworks and drilling equipment. This indicates that the remaining constraint is logistical and weather related, rather than permitting related.

The design of the drill program has consequently been enlarged to reflect both the extended target and the objective of obtaining sufficient material for metallurgical testing.

The announcement summarises the change as follows:

In the background section of the announcement, Heavy Rare Earths Ltd also notes that, based on historic data, it anticipates that the upcoming drill program may allow the definition of a maiden resource estimate for a high-grade tin resource at South Ridge, subject to drilling results and subsequent evaluation.

For investors, the combination of full approvals and an expanded drill design provides visibility on the next field-based milestones, with scope for results to inform both resource estimation and early-stage metallurgical understanding.

Project context: Prospect Hill and South Ridge

The South Ridge tin prospect forms part of the Prospect Hill Project, which is located along the north-western margin of the Curnamona Craton in eastern South Australia.

Key context points from the ASX announcement include:

• Prospect Hill comprises three contiguous exploration licences (EL5891, EL6271 and EL6933)
• The project area covers approximately 75 km²
• The western portion of the tenement block features outcropping rocks of the Mt Painter and Mt Babbage inliers, which host polymetallic mineralisation in Palaeoproterozoic volcanic rocks
• The project was initially acquired by Heavy Rare Earths Ltd for its uranium potential
• The company subsequently renegotiated for all mineral rights, including tin, and inherited a large legacy assay dataset generated by several past operators focused on tin

According to the review by Heavy Rare Earths Ltd, this historical dataset highlighted South Ridge as the most advanced tin prospect on the tenure, with:

• 56 historic drill holes and costeaning along a 600-metre section of the now 1.85 km structure
• An interpreted linear, steeply dipping structural zone hosting tin mineralisation

The upcoming drill program has been described as being designed to:

• Expand the known mineralisation model along strike and down dip
• Test under-explored sections, including the 900-metre western zone
• Generate samples for metallurgical test work

This activity is aligned with the stated aim of moving towards a maiden MRE at South Ridge, subject to exploration outcomes.

Why this update matters to investors

For investors following Heavy Rare Earths Ltd and the broader tin exploration space, several aspects of this announcement may be of interest:

1. Scale of the structural target

   • The mapped strike length of the main South Ridge Shear zone has increased to 1.85 km.
   • The host structure is reported to be up to 10 metres wide and steeply dipping.
   • This provides a larger structural framework within which mineralisation can potentially occur.

2. Under-explored but historically mineralised western zone

   • Only 7 holes have tested a 450-metre stretch in the western zone.
   • Historical intercepts include 4 m at 1.04% Sn and 1 m at 1.38% Sn.
   • There has been no follow-up drilling on this part of the structure for more than nine years.

3. Parallel structures and system potential

   • Newly identified parallel structures proximal to South Ridge indicate additional exploration targets.
   • These structures will require further work, including laboratory assays and possible drilling, before their significance is known.
   • For investors, multiple potential lodes can increase the overall prospectivity of a project area if future drilling confirms mineralisation.

4. Operational readiness and enlarged drilling scope

   • All regulatory and heritage approvals required for the maiden drilling program are now in place.
   • The planned program has been enlarged to up to 36 holes for 3,400 metres, indicating an intention to test more of the structure and collect metallurgical samples.
   • The remaining step is logistical, awaiting road conditions suitable for heavy vehicle movement.

5. Pathway towards a maiden MRE

   • Heavy Rare Earths Ltd has indicated that, based on historic data, the upcoming drilling may support a maiden MRE for a high-grade tin resource at South Ridge.
   • An MRE would represent a key technical milestone, allowing more formal assessment of tonnage and grade for the prospect, subject to JORC Code requirements.

Key takeaway for investors
Heavy Rare Earths Ltd has reported that South Ridge now contains a mapped 1.85 km mineralised structure with multiple parallel features, full drilling approvals and an expanded maiden program targeting both known and under-explored zones. With historical high-grade tin intersections in the western segment and a clear aim of progressing to a maiden Mineral Resource Estimate, the upcoming drilling at South Ridge is positioned as a central catalyst in the company's tin-focused exploration strategy at Prospect Hill.

Ready to Explore What Heavy Rare Earths Ltd Is Building at South Ridge?

With a 1.85km mineralised structure, all drilling approvals secured, and an expanded maiden drill program now underway at South Australia's most advanced tin prospect, Heavy Rare Earths Ltd (ASX: HRE) is approaching a pivotal period in its exploration journey. For investors looking to understand the full scope of the Prospect Hill Project, the company's strategy, and what a maiden Mineral Resource Estimate could mean for HRE's future, head to the Heavy Rare Earths Ltd investor page to find out more.