King River Resources has launched a comprehensive RC drilling campaign and aeromagnetic survey at its Mindoolah Gold Project, aiming to unlock residual gold in historical waste dumps and validate structural controls beneath old workings.
- 167 RC drill holes planned across historical waste dumps
- Bulk density testing to estimate mineralised stockpile tonnage
- Aeromagnetic survey to refine geological and structural models
- Focus on key prospects: Excelsior, Cundy, Bertram’s, Mindoolah Main Reef
- Initial assay results expected by August 2026
Drilling Targets Residual Gold in Vast Historical Stockpiles
King River Resources Ltd (ASX:KRR) has kicked off a significant exploration push at its Mindoolah Gold Project in Western Australia's Murchison Province, mobilising a reverse circulation (RC) drill rig to test an unexpectedly large volume of historical waste dumps and stockpiles. Recent 3D LiDAR mapping revealed a surface-excavated volume exceeding 1.08 million tonnes; far beyond the 38,589 tonnes reported in historical production records. This discrepancy suggests substantial residual gold may remain locked in these stockpiles, a prospect KRR is eager to quantify through systematic drilling.
The program entails 167 holes totalling 1,690 metres across three priority waste dumps: Excelsior, Cundy, and Mindoolah Main Reef. Excelsior, the largest of the dumps, has limited historical sampling but returned some gold grades above 1 g/t in previous rock chip assays, while Cundy and Mindoolah Main Reef have no recorded sampling, representing fresh ground for evaluation. Complementing the drilling is a bulk density characterisation program designed to improve tonnage estimates and volumetric reconciliation, critical steps to assess the economic potential of these stockpiled materials.
Multi-Angle Drilling to Unlock Structural Complexity
Beyond surface stockpiles, the RC program targets deeper hard-rock mineralisation beneath historical open pits and underground workings at key prospects including Excelsior, Cundy, Bertram’s, and Mindoolah Main Reef. King River Resources aims to validate and refine historical drill data by testing mineralisation from multiple orientations, addressing concerns that previous drilling may have been suboptimal or misaligned with the true geometry of the lodes.
For instance, at Excelsior, the company plans to deploy NE–SSW scissor holes to intersect mineralised lodes perpendicularly, overcoming limitations of earlier west–east drill orientations. Similarly, at Cundy, new interpretations suggest mineralisation trends oblique to historical pits, prompting a targeted, multi-directional drilling approach to better define structural controls. Bertram’s remains a high-priority target with historic grab samples returning grades up to 40.23 g/t Au, yet the area has seen limited and potentially poorly oriented drilling, leaving significant upside for structural and grade continuity assessment.
Aeromagnetic Survey to Enhance Geological Understanding
Parallel to drilling, KRR has scheduled an aeromagnetic survey to commence in June 2026, with data processing expected through July. This survey will integrate with existing geological and geophysical datasets, including the recent LiDAR terrain mapping, to sharpen the understanding of lithological contacts and structural features controlling mineralisation. The combined datasets will guide future drill targeting, especially beneath the Mindoolah Main Reef prospect, where broader drilling awaits magnetic survey results to clarify complex lithological and structural settings.
Managing Director Graham Gadsby emphasised the efficiency of combining physical drilling with geophysical data acquisition, stating that this dual approach accelerates target evaluation and improves the chances of identifying economically viable mineralisation extensions.
Historical Data Underpins Exploration Strategy
The Mindoolah Gold Project has a rich mining history dating back to the early 1900s, with historical underground and open pit operations reporting high-grade gold extraction, including average head grades above 19 g/t Au in the 1980s. However, King River Resources’ recent volumetric assessments and structural reinterpretations challenge the completeness of historical mining records and drill orientations, suggesting significant unmined mineralisation remains.
The company’s exploration team has meticulously integrated historical drilling, surface geochemistry, pit-wall mapping, and advanced digital terrain models to design this maiden RC drilling program. The upcoming assays, expected by August 2026, will be crucial to confirming the presence and extent of residual gold in both surface stockpiles and deeper lodes, potentially reshaping the project’s resource profile.
Bottom Line?
King River Resources’ combined drilling and aeromagnetic survey at Mindoolah sets the stage for a critical reassessment of unmined gold, with assay results poised to redefine the project’s value proposition.
Questions in the middle?
- Will assay results confirm economically significant gold in historical waste dumps?
- How will new structural insights from aeromagnetic data influence future drill targeting?
- Can multi-oriented drilling overcome limitations of past exploration to unlock deeper mineralisation?