QEM (ASX:QEM) has completed a review of historical data from its Big It Tungsten Project in Idaho, US, identifying opportunities to test mineralisation beneath and along strike from the former underground mine.
Historical records indicate Big It produced tungsten concentrates grading 67–75% tungsten trioxide (WO₃) for US wartime programs.
A limited suite of underground rock samples collected in 2016 returned individual maximum values of 2,980 parts per million (ppm) W, 19.50% antimony, and 11.15 grams per tonne gold.
The maximum values came from separate selective samples and should not be interpreted as representative grades, widths, or evidence of continuous mineralisation.
Managing Director Robert Cooper says the compilation provides a foundation for planning exploration at the project.
“The combination of historically verified tungsten production at Big It, together with previous significant sampling results for antimony and gold, highlights this potential,” Cooper says.
The project comprises three unpatented federal mining claims covering about 60 acres (24.3 hectares) and a further 101 acres of associated landholdings in Shoshone County. QEM acquired Big It through its purchase of Freshwater Metals in August.
Exploration undertaken by the US Defence Minerals Exploration Administration in 1952–1953 identified two additional tungsten ore shoots.
Historical records report average grades of 4.45% WO₃ across a 17.2cm vein width and 7.45% WO₃ across 10.9cm.
These results predate modern reporting standards and have not been independently verified by QEM. The company says they should be treated as indications of the historical tenor and distribution of mineralisation rather than mineral resource estimates.
Government records document about 380m of lateral underground development, along with raises, winzes, and historical stopes. QEM says the workings could provide direct access for geological mapping and systematic sampling, subject to safety and accessibility.
The mineralised vein system remains largely untested beneath the historical workings, while possible strike extensions and parallel structures have received limited modern exploration.
QEM says it plans to begin with geological and structural mapping, surveys of accessible underground workings, and systematic surface and underground sampling.
The company also intends to verify a 2022 soil sampling program that was interpreted by a previous operator to have outlined a parallel gold anomaly. QEM says the underlying laboratory dataset has not yet been located.
A second phase would drill-test the continuation of the historically mined vein system and evaluate other structural and vein targets using surface geochemistry and targeted geophysics.
The review comes amid efforts by the US to strengthen domestic critical mineral supply chains. China currently accounts for about 83% of global tungsten production, according to figures cited by QEM.
Write to France Pinzon at Mining.com.au
Images: Unpslash
