GBM Resources has extended gold mineralisation beyond the existing 1Moz Twin Hills resource, including an 18-metre intersection grading 12.01g/t gold. Early flotation tests returned recoveries of up to 99%, while the company held $23.3 million in cash and no debt at quarter end.
- 18m at 12.01g/t gold outside the 309 resource, including 2m at 104.61g/t
- 101m at 2.63g/t gold at Lone Sister supports potential local grade uplift
- Initial rougher flotation recoveries ranged from 91.9% to 99.0%
- 8,000m Yandan drilling program has commenced
- $23.3m cash, $2.3m in listed investments and no debt at 30 September
Twin Hills drilling opens a second resource-growth front
GBM Resources Limited (ASX:GBM) is approaching its next Twin Hills resource update with evidence of both extensions beyond the current mineral resource and potentially stronger grades within it. At the 309 deposit, hole TNDH048 returned 18m at 12.01g/t gold from 247m, including 2m at 104.61g/t, outside the existing resource boundary. The intersection sits about 85m from an earlier 37m at 5.00g/t result, creating a defined area for follow-up drilling rather than a lone high-grade hit.
The latest results build on the 18m Twin Hills drilling result, which previously highlighted mineralisation beyond the 309 resource. TNDH048 also returned a separate 5m at 6.66g/t from 189m, while TNDH050 produced 5m at 5.80g/t from 118m. GBM says the results broaden the dataset outside the current 309 model and are helping refine the geometry and continuity of the mineralised system.
Lone Sister result points to possible grade uplift
At Lone Sister, hole LSDH020 delivered the broadest headline result: 101m at 2.63g/t gold from 256m, including 9m at 6.55g/t and 4m at 10.35g/t. GBM said a substantial portion of the interval returned grades materially above the current resource model, supporting the possibility of local grade uplift when the data is incorporated into future estimation work.
The result follows the 101m Lone Sister gold intersection and is complemented by LSDH011, which returned 37m at 2.40g/t outside the current Lone Sister resource, including 4m at 7.77g/t. Around 60% of Twin Hills’ 50,000m Stage 2 program is complete, with drilling targeting resource growth, higher-grade continuity and areas where historical drilling may have created apparent gaps in the block model.
Flotation tests support conventional processing studies
Initial metallurgical work adds a development angle to the exploration story. Rougher flotation tests returned gold recoveries of 92.0% to 99.0% across 309 and Lone Sister. At a 75-micron grind, 92.0% of gold at Lone Sister reported to 4.8% of feed mass, while 98.9% at 309 reported to 8.7%.
These are preliminary rougher results, not final process recoveries. Finer grinding to 45 microns did not materially improve recovery and produced lower concentrate grades with higher mass pulls. Further cleaner flotation, reagent optimisation and cyanide-leaching work will be required before GBM selects a preferred flowsheet. The Twin Hills flotation testwork therefore strengthens the processing case, but does not settle it.
Yandan drilling adds a second catalyst
GBM has also started an 8,000m Stage 1 program at Yandan, split evenly between reverse-circulation and diamond drilling. The company is prioritising East Hill, where it reports a high-grade core of 1.1 million tonnes at 5.7g/t gold for 201,000 ounces within a broader East Hill mineral resource of 12.8Mt at 1.1g/t for 443,000 ounces.
New geophysical interpretation has led GBM to describe Yandan as a broader intrusive-centred hydrothermal system, with untested anomalies extending beyond the current resource footprint. The immediate milestones are assay results from priority East Hill holes, completion of resource drilling in November and an updated East Hill mineral resource estimate targeted for the first half of 2027, subject to drilling results.
Cash funds the program, but exploration remains expensive
GBM ended September with $23.3 million in cash, $2.3 million in listed investments and no debt. It spent $6.765 million on exploration and evaluation during the quarter, with total operating and exploration outgoings of $8.146 million. On the Appendix 5B calculation, that equates to 2.9 quarters of funding at the quarter’s spending rate. That is a mechanical estimate based on one quarter of expenditure, not company guidance, and could shift as Twin Hills, Yandan and regional programs advance.
The next hard test is the planned Twin Hills mineral resource update in the December quarter. It will need to convert scattered extensions and above-model intervals into a coherent estimate, while the metallurgical program must establish whether the encouraging rougher recoveries can survive the cleaning and concentrate-treatment stages.
Bottom Line?
The upcoming Twin Hills resource update must translate promising drill intersections into ounces, grades and a credible development pathway before the exploration momentum can be judged.
Questions in the middle?
- How much additional contained gold will the next Twin Hills resource estimate recognise outside the current boundaries?
- Can cleaner flotation and cyanide-leaching work preserve the strong preliminary recoveries at commercially useful concentrate grades?
- Will Yandan’s Stage 1 drilling confirm that the deeper geophysical anomalies extend the high-grade East Hill system?