Gascoyne Resources Limited has intersected multiple zones of shallow, high-grade gold mineralisation in the Eastern Footwall area of Gilbey’s open pit, the main ore source at its 100%-owned Dalgaranga Gold Project in Western Australia.
The drilling has highlighted the potential to delineate significant new mineralisation immediately adjacent to the main operating pit at Dalgaranga and directly below the Eastern Ramp which was previously used to access the pit.
Notably, every drill-hole assayed so far at the Eastern Footwall targets has intersected shallow gold grades above 0.5g/t across multiple stacked zones beneath the historically mined upper main Gilbey’s orebody, with strong intersections including:
- 2 metres at 2.40g/t from 11 metres;
- 3 metres at 5.54g/t from 26 metres including 1metre at 14.8g/t; and
- 5 metres at 38g/t from 50 metres, including, 1 metre at 176g/t
Looking ahead, the results represent another important near-mine exploration breakthrough by the company’s geology team, highlighting the significant opportunity to grow mineral resources and ore reserves and extend the mine life at Dalgaranga.
“Exciting exploration breakthrough”
Gascoyne Resources managing director and CEO Simon Lawson said: “Our expansionary nearmine drilling continues to outline new mineralised areas across multiple fronts at Dalgaranga.
The three reverse circulation rigs we currently have employed are extremely busy drilling for gold at Gilbey’s North, Plymouth, Gilbey’s South and are now following up these spectacular shallow gold horizons in the footwall of the main operating Gilbey’s open pit – which represents another exciting exploration breakthrough.
“Standing back from the detail at the main Gilbey’s deposit, you can see a number of strike parallel mineralised horizons within the overall deposit geometry heading both north-south through the Gilbey’s and Plymouth deposits as well as the recently discovered Gilbey’s North prospect, and also through the east-west Plymouth and Sly Fox deposits.
“Adding to this regional observation, mining of the main deposit at Gilbey’s had historically encountered and mined several high-grade areas adjacent to the main orebody in the footwall of the Gilbey’s pit.
“ In fact, a small area of this high-grade footwall material was mined in January 2022, contributing to our record March 2022 quarter.”
Significant “in-mine” discovery
The Gilbey’s Eastern Footwall target is comprised of a number of individual targets previously thought to be isolated north-eastern splays, which now appear to be semi-continuous horizons running strike parallel to the main Gilbey’s orebody.
An initial drill program has intersected multiple mineralised lenses with gold grades of up to 176g/t along about 300 metres of strike adjacent to the main Gilbey’s ore body.
All intersections were found less than 1 kilometre west of the more-than-2.5 million-tonne-per-annum Dalgaranga processing plant, within the currently operating Gilbey’s open-pit mining operation and are easily accessible from the Eastern Ramp.
Lawson adds: “Our geology and mining team hypothesised that there may be a lot more continuity both along-strike and down-dip in the Eastern Footwall areas and that, rather than isolated splays, these high-grade 'pockets' might actually be continuous mineralised zones running the length of the pit and beyond – a length of over 1,000 metres of strike.
“Using the existing eastern ramp infrastructure as drill platforms, holes were drilled into the footwall at roughly 50-metre spacing along strike, where achievable, and a mixture of vertical and steeply east-dipping holes were drilled into the footwall to test this theory.
Drill program
As recently as January 2022, the Eastern Footwall material has been mined from existing infrastructure and processed at good recoveries with a high gravity recovery component.
Three reverse circulation (RC) drill rigs are currently on-site at Dalgaranga targeting:
- Gilbey’s North discovery – north-west step-out extension and resource in-fill drilling – assays pending for around 25 holes;
- Eastern Footwall – in-fill and follow-up drilling for grade control and near-term mine scheduling – assays pending for around 5 holes; and
- Gilbey’s South – follow-up and resource drilling as part of the assessment of future south mine ramp options – assays pending for around 15 holes.
Lawson adds: “Every single drill-hole we have had returned from the lab so far, drilling into the footwall target areas, has encountered significant gold grades above 0.5g/t, with some holes intersecting multiple mineralised horizons and some ending in mineralisation.
“This provides further validation of our targeting theory at Dalgaranga.
“Keep it simple, drill your best target and the result either moves into the mine plan or we rapidly test another target – and then repeat, repeat, repeat.“
“All the while, our disciplined approach to mining and minimising costs is continuing to deliver results, despite increasing cost pressures, our strategic review is delivering outcomes with the recently announced sale of the Mumbakine Well Project to Capricorn Metals, and we intend to push forward generating consistent cash-flow from Dalgaranga in support of our ongoing initiatives to extend mine life and make new discoveries.”