The Terminus (and Vancouver) occurrences are located on the east side of American Creek, about 5.5 kilometres north-northeast of the confluence with the Bear River, about 24 kilometres north of Stewart.
The area is underlain by north trending, east-dipping rocks of the Lower Jurassic Unuk River Formation (Hazelton Group) (Bulletin 58; 63). Green andesite tuff and agglomerate, with interbeds of siltstone and minor limestone, lie on the eastern limb of the north-northwest trending American Creek anticline. Several types of dikes and intrusions have been reported. They include quartz feldspar porphyry stockworks and dikes, siliceous dikes, andesite or basalt dikes and diorite and granodiorite stocks and/or dikes.
North to north-northeast trending shears are the most important structural features. They include the mineralized Terminus, Evans and Camp shears. These shears have been traced for 1000, 700 and 200 metres, respectively. East-trending shears, faults and joints appear to postdate the mineralized shears.
The mineralized shears comprise vuggy to brecciated quartz and quartz-carbonate veins with up to 5 per cent pyrite and small blebs of sphalerite, galena and tetrahedrite. Dikes, especially light coloured siliceous ones, are commonly intimately associated with the mineralization and may also be mineralized.
The Terminus vein (and accompanying dikes) dips 45 to 50 degrees east in the shear and strikes 005 degrees. Discrete mineralized veins are generally less than 0.6 metre wide. A mineralized quartz vein, breccia and gouge zone in the north stope (on the crosscut level) is up to 2.1 metres wide. The host shear zone is silicified; siliceous dikes form both the footwall and hangingwall. The better mineralization lies along the hangingwall. A sample from the surface assayed trace gold, 7753 grams per tonne silver, 2.24 per cent lead, 0.69 per cent zinc and 0.23 per cent copper across 0.15 metres (Assessment Report 20976).
The Evans veins occur on the Evans claim (Lot 3231), about 360 metres southeast of the Terminus portal. Two steeply west dipping, quartz-carbonate breccia veins are separated by about 10 metres of basic dike and fractured volcanics. A sample from the west vein assayed 27.4 grams per tonne silver, 0.07 gram per tonne gold, 3.49 per cent lead, 0.61 per cent zinc and trace copper across 1.8 metres (Assessment Report 10124).
The Camp vein occurs on the Ayrshire claim (Lot 3232), about 300 metres west-southwest of the Terminus portal. A 0.6 metre wide vein of massive sphalerite and galena is hosted in a 0.6 metre wide siliceous dike that trends 150 degrees and dips 55 degrees east. The vein lies adjacent to the north trending Camp shear. The sulphide vein assayed trace gold, 4085 grams per tonne silver, 24.2 per cent zinc, 9.79 per cent lead and 0.94 per cent copper (Assessment Report 20976).
The Vancouver adit, about 240 metres north of the Terminus portal, contains massive pyrite-pyrrhotite mineralization associated with siliceous and chloritized volcanics. The sulphide zone has been explored by a line of cuts and a further adit to the northeast. Samples assayed negligible results.
The Terminus occurrence was probably discovered in 1910. During 1910-28, Northern Terminus Mines Ltd. (and later Terminus Mines Ltd.), conducted exploration work on the property. By 1911, a 13.8-metre shaft, an opencut and a short tunnel had been completed. That year, a shipment of ore (10.8 tonnes) assayed about $200 per tonne. Most of the underground work was apparently completed in 1924 and comprised a 200 metre long crosscut (adit), 90 metres of drifting, a raise, a winze and, about 50 metres south of these workings, a prospect shaft. The crosscut intersected the Terminus vein about 22 metres below the surface exposure. In 1925, Vancouver Mines Ltd. performed exploration on the immediately contiguous claims. This work included two adits and several opencuts on the Hope 1 Fraction, about 240 metres north of the portal of the Terminus adit; and pits on the Hope veins on the Hope No. 2 Fraction (104A 017), about 700 metres east of the portal. From 1925-49, 24.5 tonnes were high graded from the property; 152,312 grams of silver, 3944 kilograms of lead and 5036 kilograms of zinc were recovered. No further work was reported until 1981 when Gatrow Resources Inc. conducted a prospecting and sampling program on the Terminus-Vancouver claim groups. Most of the previous workings were resampled. In 1988, D. Cremonese flew a heli-borne VLF-EM and magnetometer survey over the Ernst 1-2 and Pabicia claims, which included the area of the occurrences. In 1990, Hyder Gold Inc. performed geological and geochemical work on the Terminus-Vancouver property; this work was done mainly on the Hope claims. An in-situ mineral inventory of the Terminus vein was estimated in 1990 to be 5182 tonnes grading 391.9 grams per tonne silver, 0.92 per cent zinc and 0.76 per cent lead (Assessment Report 20976). That same year, D. Cremonese (Amphora Resources) flew a heli-borne VLF-EM and magnetometer survey over the Elk 2-3, Bunt 1-4 and Basin 1-4 claims. The survey included the area of the occurrences. In 1991, the Basin 1 claim was staked around the Terminus workings which occur on several Crown grants. The workings and the immediate area were sampled during investigations on the adjacent Basin property. During 2005 through 2010, Auramex completed programs of prospecting, geological mapping, geochemical sampling and airborne geophysical surveys on the area as the Bear River-Surprise Creek property.
