Western Star Resources Inc. has released the results of a district-scale three-dimensional geophysical inversion across its Rowland and White Star tungsten properties in Elko County, Nevada. The modelling has identified buried and partially exposed intrusive bodies, refining the fault network believed to channel mineralising fluids into the tungsten skarn system. Notably, the Company's highest-grade rock chip samples, 4.02% WO3 at Rowland and 3.00% WO3 at White Star, both coincide spatially with the contact between these modelled intrusives and the carbonate host rock. The modelled intrusive framework extends well beyond the mapped outcrop, opening substantial new search space across both properties.
Blake Morgan, CEO and President of Western Star, commented, "This is the result we were hoping for. The inversion has modelled intrusive bodies spatially associated with areas where we sampled high grade tungsten values, and it has mapped the faults that we believe carried the fluid there. That is the tungsten skarn recipe, and we can now see it in three dimensions across the whole district. Better still, the modelled intrusives are more extensive than has been previously mapped, which means the ground that has produced our best rock chips continues into untested areas." Soil geochemistry from Phase 2 is expected shortly, which will be integrated into drill hole planning.
The inversion was conducted by Warren Hughes, P.Geo., of East Coast Consulting, using a district-scale magnetic survey. The modelling defines buried and partially exposed intrusive bodies, which are essential for tungsten skarn formation. Approximately 25 kilometres of structure has been interpreted in two dominant orientations: north-east–south-west and north-west–south-east. These are interpreted as the fluid conduits that fed the skarn, representing the first structural framework mapped at property scale in this district. The modelled magnetic domains correspond closely with the units mapped by Coats (1964), adding depth and continuity to that mapping. The inversion also resolves geology beneath extensive Quaternary cover on the eastern flank of the district, providing an exploration vector into ground that cannot be mapped or sampled at surface.
Tungsten skarns form when a granitic intrusion is emplaced into a carbonate sequence. As the intrusion cools, it expels metal-bearing hydrothermal fluid that reacts with the surrounding limestone to produce garnet-rich calc-silicate rock known as skarn or tactite, where scheelite, the principal tungsten mineral, is deposited. Three elements must be present: an intrusion to drive the system, reactive carbonate rock to host the replacement, and structures to focus the fluid. The deposit model set out in the U.S. Geological Survey assessment of tungsten skarn resources across the Great Basin (Lederer and others, 2021) shows this arrangement clearly. Fault-channelled fluid is central to the model, determining where the highest-grade skarn develops.
The most important outcome of the inversion is the relationship between the modelled intrusive rocks and the Company's existing rock-chip results. At Rowland, the sample returning 4.02% WO3 sits directly on the mapped tactite where it abuts the modelled intrusive body. At White Star, the sample returning 3.00% WO3 occupies the same position on the same contact on a separate intrusive body. Both are within, or immediately adjacent to, interpreted structural corridors. The modelled intrusive extends considerably beyond the mapped outcrop, making the search space materially larger than the mapped geology alone would suggest.
The geological mapping by Coats (1964) remains the authoritative base map for the district, and the magnetic domains defined by the inversion correspond closely with the units Coats mapped, giving confidence in both datasets. The inversion adds the third dimension and continuity beneath cover, showing how far the intrusive rocks extend at depth, where the intrusive–carbonate contact runs beneath Quaternary cover, and how the structural network cuts through both. The Company intends to use this to refine the mapped geology through targeted field mapping in the next phase of work.
Soil geochemical results from the Phase 2 programme are expected shortly. These will be integrated with the three-dimensional inversion model, the interpreted structural framework, and the geological mapping to build a single targeting model for the district. Follow-up field mapping and sampling will refine the geological model, and resulting targets will be ranked to support the drill programme and permitting process now underway.
Western Star also announced it has satisfied the first performance milestone under the option agreement for the Rowland tungsten project. The milestone required increasing the total project claim area by at least 30% and identifying at least three rock-chip samples grading above 2.0% WO3. Both conditions have been met well beyond thresholds: the claim package was expanded from 84 hectares to 221 hectares, an increase of approximately 165%, and four samples returned grades above 2.0% WO3, including 4.02%, 2.69%, 2.56%, and 2.11%. The Company will issue 500,000 common shares to the vendors, valued at the 10-day volume-weighted average price immediately preceding the verification date, subject to CSE policies.
The scientific and technical information in this release has been reviewed and approved by Jasper Mowatt, MIMMM, MAusIMM, a consultant to the Company and a Qualified Person as defined by NI 43-101. The UAV magnetic survey was conducted by AJ Mining LLC using a DJI Matrice M300 platform carrying a GSMP-35U v8.0 potassium vapour magnetometer. Data processing and inversion were completed by Warren Hughes using Geosoft Oasis Montaj and MAG3D algorithm. All coordinates are reported in NAD83 UTM Zone 11N. Magnetic susceptibility is a physical rock property and not a direct measurement of mineralisation; interpretations require confirmation by drilling.
References: Coats, R.R., 1964. Geology of the Jarbidge quadrangle, Nevada–Idaho. U.S. Geological Survey Bulletin 1141-M. Lederer, G.W., et al., 2021. Tungsten skarn mineral resource assessment of the Great Basin region. Journal of Geochemical Exploration, doi:10.1016/j.gexplo.2020.106712.
