Northern Exploration Targets At The Whistler Gold-Copper Project
ANCHORAGE, AK - U.S. GoldMining Inc. reported on its high priority exploration targets for the northern part of its Whistler Gold-Copper Project in Alaska
The Whistler - Raintree mineral system, also referred to as the 'Whistler Orbit', comprises a classic 'porphyry cluster' spread over an area of approximately 5 x 5 km, containing multiple mapped and interpreted porphyry intrusions and including the established Whistler and Raintree West mineral resource deposits. Porphyry deposits are the primary source of copper globally and can also contain significant other metals such as gold, silver and molybdenum. Over 25 individual exploration targets are identified within the Whistler Orbit area, comprising a mix of mapped diorite porphyry rocks and/or surface geochemical anomalies, and interpreted diorite porphyry stocks and dykes from 3D magnetic modelling. The potential for new discoveries within the Whistler Orbit was exemplified by the recently announced drilling results south of Raintree West deposit (see news release dated February 10, 2025) which included 138.0 m at 0.99 g/t AuEq (comprised of 0.89 g/t Au and 0.05% Cu) plus 17.57 g/t Ag, 0.44% Pb and 0.95% Zn, located 500 meters south of the Raintree West deposit in an area with no previous drilling.
The Whistler Project lies within the emerging West Susitna Mineral District located just 100 miles west of Anchorage, Alaska, encompasses a contiguous land package of 53,700 acres of State mining claims. The footprint of the existing gold-copper deposits makes up <1% of the total Project area. The Company is currently planning for potential future exploration programs to test the highest ranking gold ± copper ± silver targets identified to date and to develop phased exploration programs which could commence this coming summer.
Tim Smith, Chief Executive Officer, said, "The Whistler Gold-Copper Project is located within the West Susitna Mineral District, which contains established gold, copper and silver mineral resources, plus potential for other critical metals such as antimony and tungsten. The Whistler Project, located just 105 miles from Anchorage, Alaska, encompasses three known mineral systems containing existing gold-copper-silver deposits and numerous additional potential exploration targets. Located in the north of the claim group, the Whistler-Raintree Mineral System already contains two of the three deposits delineated to date and over 25 additional individual potential exploration targets identified over an area of approximately 5 x 5 km. Also known as the Whistler Orbit, this area is underlain by a large causative batholith which has spawned a 'porphyry cluster' of multiple high-level intrusive bodies prospective for porphyry-style gold-copper-silver mineralization. We have an established exploration methodology, including the ability to directly image the intrusive bodies by inversion modeling of magnetic survey data coupled with geochemical and alteration data that is helping to vector exploration towards the highest priority targets. We are excited about the potential for systematic exploration to unlock additional resource growth at Whistler."
The Company's geological analysis of Whistler indicates significant potential to build upon the Company's first two highly successful field seasons completed at Whistler during the summer of 2023 and 2024. Our growing database incorporates knowledge compiled from drilling, relogging of historical drill core, surface mapping and sampling, and geophysical processing and interpretation. Over 25 potential individual targets have been identified to date, and the Company is working though a systematic review of their geological attributes to rank each target and to develop priorities for future exploration programs.
The Whistler Orbit area comprises a broad basin with low-lying gently sloping topography located between three mountain ranges. The flanks and lower parts of the basin are covered in variable thickness till and gravel deposits. Thicker deposits of till and gravel, see Figure 1 upper image, prevents direct surficial mapping and geochemical prospecting techniques and thus requires remote sensing techniques and/or drilling to penetrate the cover sequence to test the underlying bedrock for mineralization potential. One of the key remote sensing techniques used in gold-copper exploration is airborne magnetic surveying, where magnetometers attached to fixed-wing or rotary aircraft fly a grid pattern to map the distribution of magnetic minerals in the geology of the upper crust. Magnetic surveys are particularly useful for exploring for gold-copper porphyry -systems like Whistler, because both the host intrusive rock and the alteration associated with gold-copper mineralization can produce magnetite in sufficient quantities for detection by remote sensing.
High magnetite concentrations in circular anomalies (when viewed in plan view), often referred to as 'bulls-eye' anomalies, can be directly targeted for on-ground exploration. Over recent years, 3D subsurface 'inversion' modelling has evolved to the point where we can approximate the geometry of the magnetic anomalies below surface. Using the known Whistler Deposit as a training dataset, the magnetics processing for Whistler Orbit has modelled dozens of high-level pipe-like porphyry intrusives coming close to surface – see Figure 1 lower image. Our geologists note that a number of magnetic inversion targets have similar scale to the Whistler Deposit host diorite-porphyry, while others represent smaller 'pencil' porphyries or dyke swarms.
The Mammoth target is magnetically similar to the Whistler deposit, comprising a pipe- or plug-shaped interpreted intrusion with a similar diameter to the Whistler deposit and a 'cupola' located at its base. Mammoth is undrilled, but surface till sampling in 2024 revealed elevated gold, copper, silver and other pathfinder mineral values located proximal to the magnetic anomaly, and morphological analysis of recovered gold particles indicates irregular shaped grains which suggests a potential nearby source.
The Big White and Sunbowl targets are interpreted broadly to be extensions north and south (respectively) of the Whistler deposit host porphyry system. Big White represents the northern extension of the Whistler deposit's magnetic and Induced Polarity ("IP") chargeability anomaly, which relates to phyllic alteration associated with porphyry mineralization. Located to the south of Whistler, Sunbowl likewise represents a chargeability anomaly where mineralization may have been offset from the Whistler deposit by faulting or intrusion of post mineral porphyry.
At Raintree North and East, historic drilling of bulls-eye magnetic targets intersected elevated gold, copper and silver assays, indicative of the right rock types and hydrothermal processes that could represent nearby porphyry-style mineralization. The peak intercept from historic drillhole WH11-034, drilled in 2011 at the Raintree North prospect, comprised 120.66 meters at 0.73 g/t AuEq (containing 0.46 g/t Au, 0.16% Cu & 1.68 g/t Ag) from 177.0 meters down hole, providing encouragement for the possibility of additional porphyry mineralization in an area that warrants additional drill testing.
Hotfoot, located approx. 0.75 kilometers south of Raintree West deposit, comprises a large pipe-shaped magnetic feature similar to the host of the Whistler deposit. A single historic drill hole (RG11-032) intersected potassic and phyllic alteration suggestive of porphyry mineralization nearby. Also, the recently announced drill discovery (138.0 m at 0.99 g/t AuEq) located 500 meters south of Raintree West deposit, could represent distal veining from a relatively nearby porphyry source, for which Hotfoot is a potential candidate.
The Company's geological analysis and exploration planning remains ongoing. Potential future exploration programs would be expected to run in parallel with the Company's previously announced initial economic assessment for the Project (see news release 15 April 2025), thereby seeking to develop Whistler's full potential by investigating not only the base case mine development potential of the existing resources, but also to build a pipeline of future potential resources which could feed into a larger potential mining opportunity at the Whistler Project in future. Start dates for exploration have not been determined yet.