Key Highlights

  • Reconnaissance sampling at Coondina returned a maximum of 1.14% Li2O from fractionated lepidolite-bearing pegmatites, confirming LCT pegmatite potential in the Pilbara
  • A gossanous rock chip at Coondina yielded 151 g/t silver, 2,000 ppm bismuth and 0.3% copper adjacent to a mafic-ultramafic dyke, opening a separate base and precious metals target
  • Sampling at the Eleys project confirmed fractionated pegmatites with a maximum of 572 ppm tantalum, elevated caesium and tin, extending the known LCT corridor northeast of the historic Five Mile alluvial tin workings
  • A 167 km² hyperspectral survey has been completed over Coondina and a CSIRO Kick-Start collaboration is underway to apply machine-learning algorithms to LCT target definition

Tambourah Metals Limited (ASX:TMB) has taken a step toward demonstrating that its Eleys-Coondina project in the Pilbara region of Western Australia carries genuine LCT pegmatite potential, releasing reconnaissance sampling results that point to mineralisation across multiple target types. The project, located approximately 80 kilometres southwest of Marble Bar, sits within the geological setting associated with some of the Pilbara's most significant spodumene deposits, including Wodgina, Pilgangoora and Tabba Tabba.

The Eleys-Coondina project is tied to the fractionated Split Rocks Supersuite, the same intrusive suite linked to those major lithium discoveries. Despite this proximity, the project has seen minimal modern exploration for pegmatite-hosted LCT mineralisation, which is part of the rationale for Tambourah's current program.

Coondina: Lepidolite Pegmatites and an Unexpected Silver Discovery

Fieldwork at Coondina involved extensive traverses and the collection of 79 rock samples across the project area. The results identified a series of lepidolite-bearing fractionated pegmatites spatially associated with a mapped greenstone inlier. These features are geochemically distinguished by erratic but generally elevated beryllium, caesium, lithium, tin and tantalum, which are the elemental signatures characteristic of highly evolved LCT systems.

The best lithium result returned 1.14% Li2O, while other samples displayed the broader suite of pathfinder elements that exploration geologists use to assess pegmatite fractionation. Outcrop in the area is variable, with the lepidolite-bearing pegmatites present as laterally extensive dykes approximately one to two metres wide dipping shallowly to the south. Scree cover in parts of the project means the full thickness and continuity of the pegmatites remain to be determined.

Separately, field traverses identified a gossanous malachite-bearing outcrop adjacent to an east-west trending mafic-ultramafic dyke. First-pass rock-chip sampling of this gossan returned highly anomalous silver at 151 g/t, 2,100 ppm bismuth and 0.39% copper. Sampling along strike reported mildly elevated values of both silver and bismuth, indicating potential for a significant mineralising event associated with the intrusion. The company has flagged plans to rapidly extend sampling over this newly identified target and test for platinum group elements.

Notably, a limited number of fluorite-bearing pegmatites were also identified at Coondina, which the company interprets as indicating a possible hybrid pegmatite association between LCT and NYF (niobium-yttrium-fluorite) end members. Such hybrid systems are relatively unusual and can indicate complex, multi-stage mineralising events.

Eleys: Tantalum Confirmed, LCT Corridor Extended

At the Eleys project, sampling followed a northwest-trending structure hosting pegmatites historically worked for tantalum. The work confirmed fractionated pegmatite intrusions northeast of the historic Five Mile alluvial tin operation, with a maximum result of 572 ppm tantalum alongside elevated caesium, niobium and tin. The area between Five Mile and the tantalum occurrence has not previously been explored for LCT pegmatite potential, meaning this corridor remains an open exploration opportunity.

Technology Accelerating Target Generation

To accelerate target definition, Tambourah has completed a high-resolution hyperspectral survey covering 167 km² at Coondina, including the area targeted by the recent sampling program. The imagery provides spatial context for the field results and will be used to guide the CSIRO Kick-Start research collaboration now underway. Initial field samples will be scanned, and results will be used to refine machine-learning algorithms specifically developed for LCT target definition. This type of collaboration with CSIRO represents a relatively cost-effective way for a small explorer to Leverage institutional-grade analytical capability.

Sector Context

The Pilbara remains a globally significant lithium province, and investor interest in early-stage LCT explorers within the region continues to track developments at operating deposits nearby. The broader lithium market has experienced significant price Volatility over recent years, which has tempered enthusiasm for greenfields exploration but has not diminished the geological interest in new pegmatite discoveries. Tantalum, as a co-product mineral in LCT systems, carries its own Demand drivers linked to electronics and aerospace applications, adding a secondary Commodity angle to projects like Eleys-Coondina.

Risks

Tambourah Metals is at a very early stage of exploration at Eleys-Coondina. Reconnaissance sampling, however encouraging, is not a reliable predictor of economic mineralisation. Outcrop variability and scree cover at Coondina means that the continuity of the identified pegmatites cannot be confirmed without additional work, including drilling. The silver and copper gossan discovery, while anomalous, requires follow-up before it can be assessed as a meaningful target. Hyperspectral and machine-learning outputs are interpretive tools that require field validation. There is no guarantee that any of the identified targets will progress to resource definition.

What to Watch Next

The company has outlined a clear set of next steps, including follow-up field sampling to extend coverage over areas geochemically identified as hosting highly fractionated pegmatites, extending rock-chip sampling over the gossanous Coondina location and testing for platinum group elements, and reviewing the hyperspectral data in the context of the CSIRO collaboration. The timing and results of these programs will determine whether Tambourah advances any of these targets toward drill testing.