A high-resolution magnetic drone survey has lit up a bag of new high-priority gold targets for King River Resources at its Mindoolah project in Western Australia after unveiling a series of previously unrecognised structural corridors and alteration zones. The company says the survey results point to a much larger, structurally controlled gold system than previously thought, extending well beyond the project’s historical mine workings in the highly prospective Murchison province.
The Perth-based explorer has now defined four priority targets for follow-up work based on interpreted hydrothermal alteration, complex fold-shear interactions and structural repetitions. King River only acquired the Mindoolah project, located about 70km north-west of Cue, in February this year and has since wasted no time in applying modern exploration techniques to the ground. And it’s not hard to see why.
The project has a long history underground workings dating back to the early 1900s. In the decades the followed shallow open pits popped up delivering high-grade results with production averaging up to 19 grams per tonne gold. The company says much of the old mining was constrained by the water table with shallow mining depths down to just 20 metres and the higher economic cut-off grades of the day potentially leaving plenty in the ground for a modern explorer.
A drone LiDAR survey and volumetric analysis conducted by King River in May identified a major mismatch between official historical production records and the amount of material actually dug up. Significantly, the review estimated about 746,000 tonnes of surface stockpiles and waste dumps remained on site, almost 340,000 tonnes more than reported hinting at overlooked near-surface potential.
Against this backdrop of historical riches and modern re-evaluation the company launched its latest geophysical work. The dataset generated from a 390 line-kilometre survey has provided King River with a coherent structural framework for the first time, allowing it to look beyond the old pits and identify compelling targets that were previously invisible in lower-resolution regional magnetic data.
King River's new targets include a broad zone of demagnetisation west of the Le Soleil prospect which the company says it interprets as a potential hydrothermal alteration system where hot fluids are forced upward and deposit new minerals. The feature sits in a complex structural corridor where multiple fault trends meet, a setting considered favourable for trapping gold-bearing fluids.
Another target dubbed the Excelsior Repeat Convergence has been identified in the same structural corridor that hosts the historical Excelsior gold workings, however it has no history of mining itself. Intriguingly, the company says it may represent an untested repeat of the same mineralising architecture found at Excelsior.
Two other targets, known as Neds Birthday and the Cundy Fold-Shear Interaction are linked to extensions and complexities around the existing Cundy prospect. Geological mapping at Cundy has previously confirmed significant folding and the new survey has now tied this to an interpreted shear structure creating a complex structural zone considered a prime target for orogenic gold.
King River Resources managing director Graham Gadsby said: "The completion of this high-resolution aeromagnetic survey represents a significant milestone in our systematic evaluation of the Mindoolah Gold Project. For the first time, we have a detailed geophysical dataset that provides a coherent structural framework across the project, allowing us to move beyond the historical workings and identify multiple high-priority exploration targets. The interpretation has highlighted previously unrecognised structural corridors, potential hydrothermal alteration systems and extensions to known mineralised trends."
Notably, King River is funding its exploration push at Mindoolah by methodically selling down its significant shareholding in Tivan Limited valued at $26.55 million as at June 30. A quarterly report in April showed the company had sold Tivan shares to fund the $825,000 Mindoolah acquisition and had resolved to sell more to bankroll upcoming exploration. It’s a savvy move that allows the company to keep the drill rods turning without needing to tap the market for fresh capital.
With a pipeline of new targets now in hand the company next moves include follow-up work on an extension of the aeromagnetic survey, targeted soil sampling and geological mapping all scheduled to kick off in September. This will all lead into a second reverse-circulation drilling campaign slated for the second half of October.
Additionally, assay results from the company’s recently completed maiden drill program at Mindoolah are now expected in mid-September following industry-wide laboratory processing delays.
With its foot firmly on a package of highly prospective ground in the Murchison, King River has quickly moved from acquisition to target generation. By applying modern geophysical tools, the company has generated a suite of new targets that suggest the historical workings at Mindoolah might just be the tip of a much larger iceberg lurking below.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
By Murray Ward
