Resolution Minerals Ltd (ASX:RML, OTC:RLMLF) has confirmed the discovery of a large-scale, open intrusion-related gold system at its Golden Gate prospect in Idaho, USA, with new drilling returning exceptionally broad mineralised intervals from surface and ending in gold.
The results mark a significant step forward for the company’s 100%-owned Horse Heaven Gold-Antimony-Tungsten-Silver Project, located just 16 kilometres from Perpetua Resources’ Stibnite gold-antimony deposit.
Horse Heaven Project location map, highlighting the location of the two current major antimony-gold-silvertungsten targets, the Golden Gate Target (where the Phase 1 Core Drilling Program was conducted) and the Antimony Ridge Target. Also highlighted is the fully-permitted Stibnite Gold Project, which is only 6km east of Horse Heaven.
Broad zones of continuous gold
Assays from two new diamond holes have reinforced the continuity and scale of the Golden Gate system, following last week’s announcement of a 189.2-metre gold intersection from the first hole in the program.
Read more: Resolution unearths broad near-surface gold zone at Horse Heaven, Idaho
- Hole HH-GG25-003C returned 253 metres at 1.50 g/t gold from surface, including 111.9 metres at 2.31 g/t gold from 130.5 metres and 18.3 metres at 3.98 g/t gold from 149.4 metres, with a peak assay of 5.91 g/t gold.
- Hole HH-GG25-002C delivered 265.2 metres at 0.60 g/t gold from surface, including 89.9 metres at 1.15 g/t gold from 121.9 metres.
All three holes drilled to date have intersected mineralisation from surface to end-of-hole, confirming that the system remains open in all directions. Elevated tungsten was also recorded in the latest holes, supporting the project’s broader multi-commodity potential.
Drill hole location map of the Phase 1 Golden Gate drill program. HH-GG25-001C, HH-GG25-002C, and HHGG25-003C are located in the central northern part of the Golden Gate Target. INSERT: Enlarged part of the plan, included to show the details of the drill hole configuration in the vicinity of HH-GG25-001C. HH-GG25-001C is the first hole at Horse Heaven to properly test un-oxidised mineralisation. Shallow, pre-RML RC drill holes (grey hole traces) are also shown, including 94-02 and 94-06.
Resolution’s maiden drilling has now defined a coherent mineralised envelope extending across several hundred metres of strike, hosted in altered quartz-monzonite and granodiorite with disseminated pyrite and arsenopyrite — typical features of intrusion-related gold systems (IRGS).
‘Exceptional outcome’ for early-stage program
Resolution’s US operations CEO Craig Lindsay said the consistency of mineralisation across the first three holes underscored the scale of the discovery.
“Following up our first hole with even stronger results from holes 2 and 3 is an exceptional outcome for the Golden Gate prospect,” Lindsay said.
“These results confirm that Golden Gate hosts a large, robust gold system with all holes returning broad gold mineralisation from surface and finishing in mineralisation,” he added. “That level of continuity and consistency is extremely rare this early in a program and highlights the potential scale and our belief that Golden Gate has all the hallmarks of a significant intrusive-related gold deposit, comparable to the major systems seen elsewhere in the district.”
Schematic cross section of HH-GG25-002C showing the local geology, highlighting the significant gold intersections, and pre-RML RC drill holes intersections draw into the plane of the cross section. Pervasive gold mineralisation is hosted two monzonites (including a lower down hole intersections of 1.15g/t gold over 89.9m). The monzonites are effected by fault breccias, which themselves host material intersections of gold. The open nature of the mineralisation is highly encouraging (purple arrows).
Intrusion-related model taking shape
Resolution’s geological team believes the mineralisation style, alteration, and sulphide assemblages are consistent with an IRGS model — a class of deposit known for large-scale, bulk-tonnage potential.
Lead geologist Austin Zinsser, who has worked in the Stibnite-Horse Heaven district for nearly 20 years, said the similarities, including structural controls, mineralisation style and geochemical profile, were striking.
“The results of our very first drill holes at Horse Heaven are excellent, and we look forward to developing a comprehensive model for Valley County’s next world-class gold deposit,” Zinsser said. “The results bode exceedingly well for the Horse Heaven Project as a whole, with other equally strong targets yet to receive drilling.”
Schematic cross section of HH-GG25-003C showing the local geology, highlighting the significant gold intersections, and pre-RML RC drill holes intersections draw into the plane of the cross section. Strong pervasive gold mineralisation is hosted in both the monzonite (including 1.88g/t gold over 45.72m) and granodiorite (including 2.31g/t gold over 111.86m), lower-grade, but still significant god mineralisation is hosted in fault breccias. The cross section shows how the pervasive gold mineralisation of HH-GG25-003C traverses a repeating sequence of fault breccias, structurally-bound monzonites and granodiorites. Together with the open nature of the mineralisation, this is highly encouraging (purple arrows).
Next steps and upcoming catalysts
Resolution has completed 10 diamond drill holes in its Phase 1 program, with assays from seven additional holes expected progressively over the coming months. A reverse circulation (RC) rig is now being mobilised to expand drilling around the discovery zone.
In parallel, the company is finalising a project-wide stream sediment program and applying for a new 50-hole drill permit to support follow-up exploration at both Golden Gate and Antimony Ridge, where extensive near-surface antimony mineralisation has been mapped.
Vertical integration and downstream ambitions
Resolution is also moving quickly to build downstream capability. Last week, the company announced an agreement to acquire a 25-acre site adjoining Horse Heaven that includes a processing mill, tungsten stockpiles, power infrastructure, and industrial water rights.
The acquisition could accelerate development of both the antimony and tungsten components of the project, positioning Resolution among the few US-based companies with in-country processing capability for these critical minerals.
Outlook
With all three initial holes ending in mineralisation and multiple targets still untested, Resolution says Golden Gate is shaping up as a discovery of district-scale potential — one that aligns with US government priorities to secure domestic supply chains for gold, antimony, and tungsten.
Assay results from the remaining holes, including deeper sections of HH-GG25-001C, are due in the coming weeks, potentially setting the stage for an expanded drilling program through the December quarter.
“With multiple targets still to test across the broader Horse Heaven Project, including Antimony Ridge, our confidence continues to grow that we’re on the verge of uncovering a truly district-scale gold system with complementary known tungsten and antimony mineralisation,” Linday said.