OzAurum Resources Confirms Strong Heap Leach Results at Mulgabbie North
OzAurum Resources (ASX: OZM) has reported the first batch of results from a major grade control drilling campaign at its Mulgabbie North Gold Project in Western Australia's Eastern Goldfields. The OzAurum Resources Mulgabbie North high grade shallow gold drilling results come from 84 reverse circulation holes totalling 3,010 metres, representing just the first phase of a planned 18,000-metre grade control programme.
The company has intersected high-grade, near-surface gold across multiple drill holes within an ancient river system stretching more than 4 kilometres in interpreted strike length. With mineralisation remaining open along the full ancient river trend, and an existing ~260,000-ounce Mineral Resource already in place, these early results suggest meaningful upside as OzAurum advances its understanding of this unique gold system.
What immediately stands out is the combination of grade and depth. The gold is sitting close to the surface, with most intercepts coming from between 20 and 35 metres, which has direct implications for potential mining economics.
Grade control drilling at these depths is typically the precursor to defining mineable ore envelopes. Furthermore, the results validate the high-grade character of the system and provide strong early encouragement for the remainder of the programme.
Standout intercepts from the first 84 holes include:
| Hole ID | From (m) | Length (m) | Grade (g/t Au) | Notable High-Grade Interval |
|---|---|---|---|---|
| MNORC409 | 26 | 6 | 4.46 | 1m @ 17.34 g/t Au from 27m |
| MNORC417 | 27 | 4 | 4.46 | 1m @ 12.02 g/t Au from 27m |
| MNORC426 | 27 | 4 | 4.06 | — |
| MNORC436 | 27 | 4 | 2.05 | 1m @ 6.99 g/t Au from 28m |
| MNORC460 | 24 | 5 | 1.93 | — |
| MNORC418 | 28 | 3 | 2.57 | — |
| MNORC381 | 26 | 4 | 1.60 | — |
| MNORC457 | 24 | 1 | 3.68 | — |
These results are consistent with the high-grade character that has defined this system since earlier drilling campaigns. Historical intercepts at the project include a remarkable 1m @ 162 g/t Au and 1m @ 31 g/t Au reported in May 2021, as well as 4m @ 10.2 g/t Au from the same campaign.
The current grade control programme is designed to systematically test the continuity and width of this mineralisation across a defined area within the existing resource envelope.
CEO and Managing Director Andrew Pumphrey commented: "These results continue to demonstrate the strong grade profile and near-surface nature of the ancient river system at Mulgabbie North. With drilling ongoing across a 4km trend, we see clear upside to define additional high-grade ounces that could have a meaningful impact on future development scenarios, particularly given the shallow depth and favourable geometry of the mineralisation."
An ancient river system, or paleochannel, is a former waterway that has since been buried or preserved beneath the surface. In the Eastern Goldfields of Western Australia, these ancient drainage systems acted as natural traps for gold eroded from primary hard rock sources and transported downstream.
Over geological time, gold accumulated in specific sections of these channels, often where flow velocity changed or where the channel geometry created natural settling points. At Mulgabbie North, OzAurum has mapped this ancient river system over a strike length of more than 4 kilometres, with geological interpretation confirming a northwest flow direction and a 30-metre height drop over the 4km extent.
Ancient river gold deposits in the Eastern Goldfields have a proven track record of high-grade, low-cost production. A directly comparable analogue is the Kanowna ancient river operation, which produced approximately 70,000 ounces via open pit and heap leach mining, with gold recoveries exceeding 85%.
This recovery rate is notably strong and reflects the suitability of ancient river gold to relatively simple, cost-effective processing methods. In addition, the Kanowna ancient river exploration ultimately led to the discovery of the ~8 million-ounce Kanowna Belle gold deposit, one of the most significant primary gold discoveries in the region.
The current grade control drilling is operating within the footprint of OzAurum's already-defined Mulgabbie North Mineral Resource. Understanding this baseline helps frame the potential impact of ongoing results.
Mulgabbie North Mineral Resource Estimate (JORC 2012, reported 18 July 2023):
| Classification | Tonnes | Grade (g/t Au) | Ounces |
|---|---|---|---|
| Measured | 1,475,000 | 0.82 | 39,000 |
| Indicated | 5,620,000 | 0.71 | 128,000 |
| Inferred | 4,543,000 | 0.64 | 93,000 |
| Total | 11,638,000 | 0.70 | ~260,000 |
Reported at 0.30 g/t Au cut-off to a depth of 150m. Rounded to appropriate confidence levels.
The ancient river system, which sits west of the Relief Shear at Mulgabbie North, is partially captured within this resource. Importantly, mineralisation remains open along the full 4km trend, meaning that successful grade control and step-out drilling has the potential to add ounces above and beyond the existing inventory.
The company has explicitly flagged this as an opportunity to expand the Mineral Resource base and enhance the feed inventory for a potential heap leach development pathway.
The 84 holes reported represent only 3,010 metres out of a planned 18,000-metre grade control programme, meaning roughly 83% of the planned drilling remains to be completed and reported. This is a significant pipeline of upcoming newsflow for investors tracking this story.
Key upcoming activities and milestones to watch:
Several elements of this announcement combine to build a compelling near-term investment narrative for OzAurum. The OzAurum Resources Mulgabbie North high grade shallow gold drilling results demonstrate multiple value drivers aligning simultaneously.
The intercepts reported here, with composite grades up to 4.46 g/t Au and high-grade internal intervals reaching 17.34 g/t Au, are well above industry averages for open-pit gold. In a global context where bulk-tonnage, low-grade deposits dominate project pipelines, high-grade near-surface mineralisation commands significant attention.
With mineralisation consistently intersected between approximately 20 and 35 metres below surface, any future mining scenario benefits from minimal stripping and low capital intensity. This is particularly relevant if a heap leach processing route can be confirmed. The Kanowna ancient river analogue, which achieved recoveries exceeding 85% via this method, provides a credible reference point.
The existing ~260,000-ounce Mineral Resource is a meaningful foundation. However, the open mineralisation along the 4km ancient river trend and the identification of a potential primary gold source to the southwest positions OzAurum to potentially grow this inventory materially as drilling continues.
Mulgabbie North sits approximately 135km northeast of Kalgoorlie and 2.5km west of the Carosue Dam gold mine, an established operational gold mine in the region. Proximity to existing infrastructure in one of the world's premier gold mining districts is a practical advantage for any emerging development story.
OzAurum Resources has delivered a first batch of grade control results that validate the high-grade character of its Mulgabbie North ancient river system and set the stage for a substantial drilling programme with significant remaining newsflow.
The combination of near-surface high grades, an established resource base, an open 4km mineralised trend, and a development pathway being actively explored through heap leach testwork gives investors multiple reasons to monitor how this programme unfolds.
With 15,000 metres of grade control drilling still to be reported, investors can anticipate a series of result releases over the coming months. Each batch has the potential to further define and expand the high-grade zones identified in this first phase, creating multiple opportunities for share price catalysts as the programme progresses.
Key Takeaway: OzAurum Resources (ASX: OZM) has demonstrated that its Mulgabbie North ancient river system hosts high-grade, near-surface gold with real potential to grow beyond the existing 260,000-ounce Mineral Resource. With over 15,000 metres of grade control drilling still to be completed across a 4km open trend, the OzAurum Resources Mulgabbie North high grade shallow gold drilling results position the company for a sustained period of exploration newsflow and potential resource growth.
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