Three of Seven Holes Reach Basement at Coober Pedy, Drilling Resumes Q3 2026

Drilling Interrupted by Challenging Sand Cover

AusQuest Limited (ASX:AQD) has temporarily suspended its maiden Reverse Circulation (RC) drilling campaign at the Coober Pedy Iron-Oxide Copper-Gold (IOCG) Project in South Australia after only three of seven holes successfully penetrated the targeted basement rocks. The drilling was thwarted by an extensive unconsolidated quartz sand unit approximately 30 metres thick, which proved extremely difficult to penetrate with the initial RC method.

The project, situated at the northern end of the Olympic Dam IOCG Province and operated under a Strategic Alliance Agreement with South32, had initially planned 15 drill holes. However, drilling conditions forced a halt after completing seven holes, with only three reaching basement rock.

New Drilling Approach and Contractor Planned for Q3

To overcome the sand cover obstacle, AusQuest is engaging a second drilling contractor to apply a mud rotary drilling technique. This method will allow the team to case off the sand unit before continuing to the planned depth of around 350 metres using either RC or diamond drilling to test the basement rocks beneath.

Drilling is scheduled to resume in the third quarter of calendar year 2026 as soon as a suitable rig becomes available. The company aims to complete at least another ten drill holes targeting priority areas identified through magnetics, gravity, and Induced Polarisation surveys.

Preliminary Geological Observations and Upcoming Assays

Two of the successfully completed holes were drilled at the Bulldog prospect, approximately 400 metres from a historical Vale drill hole known for intersecting strong potassic alteration. These holes encountered mafic to intermediate gneissic rocks with pink granitic dykes and variable chlorite alteration. Sulphide content reached up to 5%, predominantly pyrite.

Assay results from these three basement-penetrating holes are expected by the end of July 2026, which will provide the first geochemical insights into the project's mineral potential.

Project Significance and Outlook

AusQuest’s Managing Director Graeme Drew emphasised the ongoing importance of the Coober Pedy Project, describing the area as “highly prospective” due to the geological characteristics and its location within a renowned IOCG province. The company remains committed to advancing exploration despite the technical setbacks encountered.

The use of the mud rotary technique marks a tactical shift in drilling strategy, reflecting the challenges posed by thick sand cover, a common obstacle in IOCG exploration. How this adjustment will impact sample quality and drilling efficiency remains to be seen as the program progresses.