The Tom occurrence is located at an elevation of approximately 1400 metres on a south-facing slope, approximately 1.8 kilometres south of the peak of the Promontory Hills.
Rocks of the Upper Triassic Nicola Group in the Promontory Hills area are cut off by the Lower Jurassic Guichon Creek Batholith to the north and the Coyle stock to the south and are overlain unconformably by the Lower Cretaceous Spences Bridge Group to the west and the Upper Cretaceous Kingsvale Group to the east. A large, upright to slightly overturned, subisoclinal anticline has a northeast-striking axial surface and apparent low easterly plunge. Inferred faults have north-northwest to northwest and northeast trends.
The occurrence area is underlain by ash tuff, volcanic sandstone and volcanic breccia with intercalated augite plagioclase andesitic lavas. These lithologies comprise the core of the major fold and are locally strongly faulted. Mineralization consists of disseminations and fracture fillings of pyrite, chalcopyrite and specular hematite. Alteration minerals include epidote, calcite and chlorite.
A large historical trench, located approximately 550 metres north of the Tom occurrence, exposes a volcanic breccia hosting minor specular hematite with rare grains of chalcopyrite and minor malachite associated with epidote.
Work History
In 1958, Centennial Mines Ltd. completed a program of trenching, three diamond drill holes, totalling 523.8 metres, and 9.9 line-kilometres of ground magnetic surveys on the as the Domino and Hank properties. Also at this time, Rio Canex Ltd. completed a program of soil sampling, geological mapping and a 9.0 line-kilometre ground magnetic survey on the area immediately southwest of the occurrence as the Dodo claims. An unknown amount of trenching and drilling is reported to have been completed on the area around this time as well.
During 1960 through 1963, Britmont Mines completed programs of geological mapping, soil sampling, trenching, five diamond drill holes, totalling 632.7 metres, and a 9.2 line-kilometre induced polarization survey on the area as the Hank and Domino claims.
In 1970, Rodstrom Yellowknife Mines Ltd. examined the area as the Hawk claims. In 1972, Red River Mines completed a soil sampling program on the area as the Hawk claims. The following year, a 1.0 line-kilometre ground magnetic survey was completed.
In 1981, Clibertre Exploration Ltd. completed a program of geological mapping on the area immediately north of the occurrence as the Charlotte claim. The following year, a program of prospecting and a ground magnetic survey was completed on the claim.
In 2012, Huldra Silver Inc. completed a 903 line-kilometre airborne geophysical survey on the area as the Thule property. This work isolated six magnetic anomalies (A through F) with the potential for magnetite skarn development, similar to the nearby Craigmont (MINFILE 092ISE035) deposit.
In 2013, Dot Resources Ltd. completed a ground electromagnetic survey on the area immediately south of the occurrence as the Promontory Hills property. The following year, a program of geological photo interpretation was completed. In 2015, a program of geological photo interpretation and 26.7 line-kilometres of ground magnetic surveys were completed on the property. In 2016, Christopher Delorme completed an 8 line-kilometre ground magnetic survey on the Promontory Hills property.
Also during 2015 through 2019, Nicola Mining Inc. completed programs of geological mapping, prospecting, airborne and ground geophysical surveys and geochemical (rock and soil) sampling on the area as the Thule Copper property. This work identified a previously unrecognized alteration type/domain of pervasive silica-pyrite alteration within sedimentary rocks of the Nicola Group extending from near the peak of the Promontory Hills southwest over a distance of approximately 2 kilometres and up to 500 metres wide. The most intense alteration completely replaces medium- to coarse-grained volcaniclastic-derived wackes and conglomerates with clasts completely pyritized.
Also in 2019, Calibre Exploration Ltd. completed a 6.0 line-kilometre induced polarization survey on the area immediately north of the occurrence as the Betty claims.
