Great Dirt Confirms 55.1% Manganese Assays at Historic NSW Mines

High-Grade Manganese Samples Reinforce NSW Project Potential

Great Dirt Resources Ltd (ASX:GR8) has delivered fresh evidence of high-grade manganese mineralisation at its Doherty and Basin manganese projects in northern New South Wales. Rock chip assays from recent sampling campaigns returned manganese oxide grades as high as 55.1% Mn, notably from the Neranghi area adjacent to historic workings. The discovery of a northeast-trending zone of manganese oxide float and outcrop over approximately 70 metres underlines the potential for further mineralisation in a district with a rich mining heritage.

Historic Mines Provide a Valuable Benchmark

The Doherty Mine, a key asset within Great Dirt’s portfolio, was a significant producer of battery and metallurgical grade manganese during the mid-20th century. Historical records indicate around 6,000 tonnes of manganese ore were extracted, supplying Eveready with battery-grade material and BHP with metallurgical-grade ore for steel production. Recent rock chip samples from mine dumps at Doherty returned up to 45.8% Mn, reinforcing the high-grade nature of the deposit. Geological mapping shows mineralisation conforming with folded chert host rocks, with the main deposit extending roughly 300 metres in length and 10 metres wide.

Mapping and Sampling Highlight Untested Zones

Detailed ground mapping and sampling at Neranghi identified massive manganese oxide float and outcrop along a northeast strike that appears consistent with the dominant fabric of the host chert rocks. While previous reverse circulation drilling in the area (holes GRCD017-GRCD019) did not intersect this high-grade trend, the recent findings suggest significant mineralisation remains untested. Several historic workings containing massive black manganese oxide were also located, pointing to a district with multiple mineralised lenses yet to be fully explored.

Environmental Compliance and Rehabilitation Completed

Great Dirt has completed full rehabilitation of all drill holes at the Doherty Project, with a formal audit conducted by the NSW Resources Regulator in May 2026 confirming compliance with environmental and regulatory standards. This successful rehabilitation effort reflects the company’s commitment to responsible exploration practices and maintaining strong relationships with regulators.

Exploration Strategy and Future Work

While the rock chip samples provide encouraging high-grade assays, the selective nature of this sampling means they are not representative of average mineralisation. Great Dirt plans to undertake additional systematic sampling and geophysical surveys to delineate the extent of mineralisation and identify potential blind deposits concealed beneath transported cover. The company’s exploration concept targets volcanogenic-exhalative stratiform manganese deposits, a style supported by multi-element geochemical signatures consistent with submarine hydrothermal systems.

These results build on previous announcements confirming high-grade manganese at Basin and Neranghi, and align with Great Dirt’s broader strategy to unlock value from historically mined but underexplored manganese districts in NSW. The company’s recent expansion into lithium exploration in Western Australia adds another dimension to its growth ambitions.