Resolution Minerals (ASX: RML) has used three-dimensional modelling to define more than 100 high-grade antimony and silver-bearing veins within 30 mineralised vein swarms, fault breccias, and stockworks across a 1,000-metre by 700m area at Antimony Ridge in Idaho.
The modelling showed the mineralised vein swarms occur in en echelon clusters across a vertical range of 250m and remain open-ended in all directions.
This indicates expanding scale potential within the company’s Horse Heaven antimony-tungsten-gold-silver project.
The update comes just two days after Resolution secured FAST-41 Transparency Coverage for Antimony Ridge from the US Permitting Council, with the company planning to conduct a significant bulk sampling program with drilling of up to 250 holes once a Plan of Operations is approved.
Resolution expects the FAST-41 designation to accelerate permitting timelines for the proposed campaign as it advances Antimony Ridge within its US-focused critical minerals platform.
Scale Emerges from Vein Swarm Modelling
The new modelling integrated mapping and sampling data from past open pits and trenches to identify a broad corridor of mineralisation containing high-grade veins surrounded by a lower grade halo of veinlets and stockworks.
Each discrete zone of antimony-silver veins extends up to 100m in strike length and the highest-grade veins reach up to 1m true thickness, with further mineralised zones and clusters expected as exploration continues.
Historical mining took place at Antimony Ridge during World War I, World War II and the Korean War, with the area serving as a key source of antimony for the US military.
Large volume rock samples collected from prior open pits returned antimony grades from 31.7% to 48.7% and averaging 39.2% antimony, 430 grams per tonne silver, and 0.92g/t gold across five samples.
Prior rock chip and soil sampling also outlined a broader lower grade halo grading between 0.5% and 2% antimony and 5 to 60g/t silver within a large antimony-gold-silver geochemical footprint.
Metallurgy and Development Plans Advance
Initial metallurgy results from two processing options are in progress from about 100kg of representative high-grade stibnite material, with Resolution expecting an antimony trioxide end product soon for pre-qualification with potential US end users.
Antimony Ridge forms part of a broader strategy to supply critical metals from central Idaho, with a major Phase 2 drilling program also due to begin in May at the nearby Golden Gate project.
US operations chief executive officer Craig Lindsay said the new modelling had revealed significant size potential demonstrating Antimony Ridge’s strategic importance as a potential US domestic antimony supply source.
“Antimony Ridge hosts an Antimony-Silver vein and vein swarm system comprising high grade large veins, stacked “en echelon”, within a broader system of mineralised stockworks with a total strike length of 1,000m, open-ended in all directions,” he said.
“Such is the consistency of the vein frequency, and the vein swarms, that there is a high probability that future work will uncover more veins and extend the length and width of the vein system.”
