Sinclair Gold has doubled the JORC Mineral Resource at its Mt Henry project to 1.8 million ounces after just 20,426 metres of drilling. The shallow resource remains open, with five rigs operating and assays pending from 25 holes outside the current estimate.
- Resource rises to 47.9Mt at 1.2g/t gold for 1.792Moz
- About 1.3Moz sits in Measured and Indicated categories
- Nearly 90% of Mt Henry and Selene ounces are within 200m of surface
- Five rigs continue step-out drilling across open mineralisation
- Next resource update expected before the end of FY27
Resource Doubles After Six Months
Sinclair Gold Ltd (ASX:SGC) has turned a 0.9Moz acquisition into a 1.8Moz gold resource in six months, lifting the Mt Henry Gold Project’s JORC estimate to 47.9Mt at 1.2g/t gold. The increase came from the Mt Henry and Selene deposits, while the smaller North Scotia and stockpile resources were unchanged.
The updated estimate contains 1.262Moz in Measured and Indicated categories, rounded by the company to about 1.3Moz, with a further 530koz classified as Inferred. That mix gives the headline growth more substance than a simple increase in tonnes, although it remains a Mineral Resource rather than an Ore Reserve and does not establish that a mine will be developed.
Shallow Ounces Support Open-Pit Study
The resource is notably shallow. Across Mt Henry and Selene, 87% of contained gold sits within 200 metres of surface, rising to 94% at Selene and 81% at Mt Henry. The estimate was constrained within optimised pit shells using a A$3,900 per ounce gold price, a 0.5g/t cut-off and an assumed 94% metallurgical recovery.
Those parameters are relevant to the project’s potential open-pit development, but they are not a development decision. Sinclair says the estimate has reasonable prospects for eventual economic extraction based on the assumptions used, while cautioning that the sensitivity figures at other cut-off grades should not be treated as Mineral Resource Estimates. The estimate also has not been externally audited.
Drilling Continues Beyond the Estimate
Only 20,426 metres, or about 41%, of Sinclair’s planned 50,000-metre drilling program was included in the updated resource. Five rigs are now operating, with assays pending from 25 holes drilled outside the current resource footprint. Results from those holes, together with ongoing step-out drilling, are intended to feed a further resource update before the end of FY27.
Mt Henry remains open along strike and at depth, with mineralisation intersected more than 480 metres below surface outside the current resource. Selene is defined to roughly 200 metres vertically below surface and also remains open down-dip and along strike. Beyond the two main deposits, the broader 16-kilometre mineralised corridor includes lightly tested prospects such as Birthday Gift, Artemis and Plutus, where historic drilling includes high-grade intervals but no JORC resource has yet been established.
Sinclair had A$38.2 million in cash at 30 June 2026, according to the announcement, giving it stated funding to continue the campaign. The next test is less dramatic than doubling a resource: whether pending assays add ounces at comparable confidence and geometry, and whether subsequent studies can translate shallow resources into an economically credible mining proposition.
Bottom Line?
The resource growth is substantial, but the next valuation test is conversion: pending assays, a larger JORC estimate and eventual studies must show that the shallow ounces can support a viable operation.
Questions in the middle?
- Will the 25 pending holes extend the resource without materially reducing grade or confidence?
- Can the open-pit assumptions used in the resource estimate withstand detailed mining, processing and capital studies?
- How much of the wider 16-kilometre corridor can be converted from historic exploration targets into JORC resources?