Australian explorer Estrella Resources has made significant progress toward uncovering what could be a massive 500-million-tonne limestone resource at its Werumata project in Timor-Leste, with drilling revealing impressive mineralisation thicknesses reaching up to 87 metres.
Major Limestone Discovery
The company reported that reverse circulation drilling at the Werumata Limestone prospect has logged substantial sheets of high-purity limestone, with the average width across the limestone blanket measuring 55 metres. The standout intersection of 87 metres represents one of the thickest zones encountered to date.
Adding to the project's potential, drilling unexpectedly encountered calcite mineralisation beneath the primary target zone. This discovery suggests the resource could be significantly larger than initial estimates indicated, providing what management describes as an unexpected bonus to the project's economics.
Manganese Success Adds Value
Simultaneously, Estrella has completed drilling at its nearby Ira Miri Manganese prospect, with equally encouraging results. The program intercepted the targeted Noni Formation containing up to 12.87 metres of 80% manganese oxides starting from just 5.13 metres depth.
Of the 45 manganese holes drilled in 2025, an impressive 29 showed visible mineralisation. The prospect also revealed thick high-grade supergene mineralisation, with samples from selected intervals collected for further analysis to determine potential premium quality characteristics.
The company is now planning to extract a bulk sample for appraisal by potential market players, moving the project closer to commercialisation.
Unique Geological Advantage
The Werumata project benefits from a distinctive geological setting where the limestone sits directly atop the manganese-rich Noni Formation. This configuration creates a rare dual-commodity opportunity, as every hole drilled for limestone can simultaneously provide information about underlying manganese mineralisation.
Weathering of the Formation has developed thick concentrations of manganese visible at surface, making exploration more efficient and cost-effective. The Noni Formation has been identified as the host unit for extensive supergene enriched manganese mineralisation, typically covered by clean limestone.
Strategic Position and Market Access
Estrella's foothold in Timor-Leste stems from management's long-standing involvement in the nation's mineral development strategy. The company established its position during Timor-Leste's first-ever minerals tender in 2023, where it was one of only four successful applicants and one of just two ASX-listed companies to secure concessions.
The explorer secured three of four exploration concessions and eight reconnaissance permits, covering prime ground across the country's limestone and manganese belts.
In May 2025, the company strengthened its commercial position by signing an exclusive marketing and offtake agreement with Indonesian energy and mining group PT Raka Energi Mandiri (REM). This partnership opens doors to South-East Asia's booming industrial minerals market and could facilitate the export of up to 500 million tonnes of limestone from Timor-Leste over the next five years.
Future Prospects and Market Conditions
Estrella Resources Managing Director Chris Daws commented on the significance of the findings, stating: "This is an important development as it confirms the findings of our mapping, sampling and surveying work, which pointed to the presence of a large sheet of mineralisation."
The company is eagerly awaiting assays from the Ira Miri manganese project, where drilling has extended the strike length of manganese mineralisation to more than 100 metres, with the resource remaining open to the northeast and southwest.
While manganese prices have experienced recent volatility due to factors including changing demand from China's steel industry and supply disruptions, the long-term market outlook remains positive. The economies of scale offered by a two-commodity project provide compelling economics, with limestone expected to carry the initial development load while manganese represents significant upside potential.
With approvals secured, drilling operations active, and a potential offtake agreement progressing, Estrella appears well-positioned to capitalise on its first-mover advantage in Timor-Leste's emerging mining sector.
