Three different mineral occurrences occur in the Bergsten basin on the east side of Thoen Mountain, 46 kilometres east-northeast of Hazelton.
The host rocks in the area are clastic sedimentary rocks of the Middle Jurassic to Lower Cretaceous Bowser Lake Group. The Bowser Lake Group includes sandstone, siltstone, shale, argillite, conglomerate and minor coal and carbonaceous units. Granodioritic dikes, stocks and plugs of the Upper Cretaceous Bulkley Intrusions cut the sedimentary rocks.
One occurrence is described as a shear-zone 2 metres in width, mineralized with galena, sphalerite, arsenopyrite and pyrite across a width of 30 centimetres. The vein strikes 050 degrees and dips northwest.
A second occurrence is located on the west side of the basin, where, across a width of six metres, three "seams" of galena and sphalerite in a gangue of rhodonite cut quartzite. Selected samples assayed 0.7 gram per tonne gold, 288.0 grams per tonne silver, 4.8 per cent lead and 5.5 per cent zinc (Minister of Mines Annual Report 1929). The mineralization strikes 040 degrees and dips southeast.
The third area is located on the east wall of the basin where minor chalcopyrite mineralization is present in several spots in granodiorite cutting quartzite.
In 1980, Jim Logan of Short Staun Minerals Corporation sampled trenches in the OK and Bergsten area. The result of his work on the Bergsten trenches is given, largely in whole as follows.
A shear zone 1.22 metres in width mineralized over a width of 0.46 metre is exposed by old trenching at an elevation of 1661.6 metres in Bergsten Basin. The shear strikes 018 degrees and dips 52 degrees north, and contains galena, zinc-blende, arsenopyrite, massive pyrite and quartz. The vein was chip sampled over a 61-centimetre width (T-13-4) in the only one of the old trenches which was not filled with slumped soil and talus. A strike length of the shear could not be determined. To the west (1690 metres elevation) in quartzites, exposed in an open cut is another vein striking 042 degrees and dipping 87 degrees southeast. This is mineralized over a width of 1 foot (30.5 centimetres) containing massive pyrite, zinc-blende and quartz (sample T-13-5). The mineralization is confined to a jointing shear which extends for 6.1 metres and appears to pinch out. Both of these veins (T-13-4 and T-13-5) contain values of silver with sample T-13-5 assaying: silver 5,745.6 grams per tonne; lead, 11.2 per cent; and zinc, 9.2 per cent (Assessment Report 8711, page 14). At this time, the zone (T-13-5) is restricted to a strike length of only 6.1 metres, although with vertical contiguity and possibly extension, this grade would make a promising high-grade ore.
In 2009, Hot property co-owner John Ostler visited the trenched area that Logan sampled in 1980 and came to the conclusion that these two trenches represented the main Bergsten occurrence that were reported on in the Minister of Mines Annual Report 1929.
In 2014, Xander Resources Inc. completed an airborne magnetic and radiometric survey over the Hot property totalling 937 line-kilometres.
