Mining heavyweight Gold Fields Limited is preparing to restart drilling operations at the expansive Edinburgh Park project in north Queensland, operated by Great Southern Mining. The campaign is scheduled to commence following the conclusion of the region's wet season, likely in March or April 2026.
Mt Dillon Prospect: A High-Priority Target
The immediate focus of the renewed exploration effort is the Mt Dillon prospect, where recent IP geophysical surveys have identified a substantial, high-chargeability anomaly located several hundred metres beneath the surface. This geological feature is particularly intriguing as it may be associated with sulphides within a preserved intrusive system.
Mt Dillon presents as a topographic high characterised by a silicified lithocap, which has shielded the peak from erosion, alongside intense hydrothermal alteration. This combination of geological attributes mirrors the protective caps observed above significant gold-copper deposits globally, heightening expectations for the site's mineral potential.
Strategic Partnership and Exploration Plans
The collaboration between Gold Fields and Great Southern Mining was established two years ago, with Gold Fields committing to earn a 75 per cent interest in the project by investing up to A$15 million over a six-year period. To date, the company has already met the initial minimum expenditure requirement of $2 million.
This joint venture specifically aims to discover large-scale epithermal and intrusion-related gold systems (IRGS), which have the capacity to evolve from subtle geological indications into major mining operations. The partners plan to drill at least two deep diamond holes directly through and beneath the IP anomaly at Mt Dillon, testing their hypothesis about the underlying mineralisation.
Previous Drilling and Geological Insights
The upcoming drilling campaign represents the second phase of exploration at Edinburgh Park, following last year's field season that involved six diamond holes across three key targets: Leichhardt Creek, Molongle, and Megan Veins, totalling 2955.6 metres.
While initial assays from Leichhardt Creek did not return economic grades, the interception of thick quartz-sulphide veining and pronounced hydrothermal alteration provides critical evidence of a robust mineralised system. These characteristics are indicative of the classic plumbing associated with substantial gold deposits, particularly intrusion-related gold systems.
Such systems are genetically connected to felsic igneous intrusions and often display distinct metal signatures, including bismuth, tellurium, arsenic, molybdenum, and tungsten. The Edinburgh Park project is considered prospective for both high and low epithermal gold-silver systems, as well as porphyry-related gold-copper deposits.
Pending Assays and Additional Targets
Assay results are still awaited from the remaining drill holes at the Molongle and Megan Veins targets. Historical data from these sites is promising: Molongle has surface rock chip samples grading up to 5.27g/t gold, while shallow drilling in 1989 intersected 24 metres at 9.36g/t gold from surface. Megan Veins has yielded historic rock chips with up to 10.55g/t gold, exhibiting classic gold-silver-base-metal veining and alteration suggestive of a nearby epithermal or porphyry system.
Positive assay results from either target could significantly increase market interest in the project. Meanwhile, ongoing geophysical and geochemical surveys continue to generate new targets across the extensive 1560-square-kilometre land package, which originally contained over 25 high-priority prospects.
Regional Context and Long-Term Outlook
The Edinburgh Park project is situated in a geologically prestigious region of north Queensland, neighbouring major operations such as the 4-million-ounce Ravenswood mine, the historic multi-million-ounce Mt Leyshon deposit, and Evolution Mining's former Mt Carlton gold mine.
Great Southern Mining managing director Matthew Keane remarked, "2026 is shaping up to be another exciting year for the Edinburgh Park joint venture. We are highly encouraged by the evidence of large-scale epithermal systems present in at least two of the target areas drilled to date. Multiple targets within Edinburgh Park display the attributes required for large-scale gold systems."
Exploration at this scale requires patience, as giant mineral systems typically unveil themselves gradually through successive drilling campaigns and accumulating geological knowledge. With Gold Fields providing substantial funding and several large-scale mineral systems already emerging, Great Southern Mining has the necessary resources and time to conduct thorough exploration, potentially unlocking a province-scale gold discovery in Queensland.
