The Bend 1 Canyon Zone is located in the Cummins River canyon near the confluence of the Cummins River with the Columbia Reach, on the east side of McNaughton (now Kinbasket) Lake. The occurrence is a few kilometres from the now defunct Big Bend Highway and approximately 109 kilometres south-southeast of Valemount.
Regionally, the area is underlain by a sequence of quartzite, carbonate and pelite of the Hadrynian Miette Group through the Lower Cambrian Gog Group to the Middle Cambrian Chancellor Group. The Gog Group is subdivided into three formations. From oldest to youngest these are the: McNaughton Formation, 500 metres of basal quartzite; Mural Formation, 100 metres of marble, sandy carbonate and shale; and Mahto Formation, 10 to 200 metres of quartzite with minor pelite. The overlying Chancellor Group has two subdivisions: the Tsar Creek and Kinbasket formations. The Tsar Creek Formation consists of mainly pelite, up to 100 metres thick, with irregular lenses of sandy carbonate and quartzite up to 100 metres thick. The Kinbasket Formation consists of greater than 800 metres of sandy carbonate with lenses of grey marble, up to 200 metres thick.
Two phases of folding and metamorphism are recognized, with metamorphism reaching amphibolite grade (biotite to sillimanite zone) resulting in a Barrovian sequence of isograds related to the first and major phase of metamorphism. Metamorphic temperatures in the area were determined to have reached up to 480 degrees Celsius at a pressure of approximately 5 kilobars.
The Porcupine Creek anticlinorium, a major, northwest-trending regional structure, lies to the east of the prospect. The units strike southeast and dip steeply southwest. Thrusting is common in the area, and to the west the Purcell fault separates the Middle Cambrian Chancellor Group from Proterozoic Windermere Super Group rocks west of McNaughton Lake.
The Bend prospect is a stratiform, synsedimentary, exhalative massive sulphide lens that was deposited within the unstable cratonic margin of Ancestral North America in the Hadrynian to Cambrian. Protoliths of the hostrock include shale, chert, pelitic chert and manganiferous carbonate units consistent with deposition in a starved basin. The metalliferous-rich sediments were probably deposited from dense, metal-rich brines derived from compaction of the sedimentary pile (Fieldwork 1986). Upon reaching the seafloor, brines denser than the seawater pooled in a major depression. Other chemical sediments, such as iron and manganese-rich metacherts above the Bend occurrence, are commonly associated with the end of sulphide deposition (Fieldwork 1986).
Stratiform mineralization of the Bend 1 Canyon Zone showing is exposed over approximately 100 metres in the canyon walls of Cummins Creek within the Tsar Creek Formation. Mineralization strikes southeast and dips 65 to 70 degrees south. Many layers in the Tsar Creek Formation are tightly folded, with axial planes striking southeast and dipping steeply southwest. The main mineralized zone is 7 metres thick and contains disseminated and massive sulphides. In decreasing order of abundance these are pyrite, pyrrhotite, sphalerite and galena with lesser arsenopyrite, chalcopyrite and magnetite in a siliceous matrix. The main zone is overlain by 6 metres of chocolate-weathering, manganiferous dolomite with disseminations of pyrite, sphalerite and galena. Quartz-filled tension cracks are common. Mineralization is underlain by greater than 13 metres of intensely silicified, garnet biotite and garnet muscovite schist with minor pink quartzite. Quartz and sericite comprise this intense silicification.
Early exploration, by 1972, indicated a dip length in excess of 200 metres and a partially exposed strike length in excess of 400 metres (Assessment Report 16544). Later work, by 1992, indicated a strike extent of approximately 2.7 kilometres and included the nearby Bend North Road Zone (MINFILE 083D 003) and Bend 2900 Zone (MINFILE 083D 015), with the thickness of the mineralized horizon decreasing away from the Cummins River canyon.
In 1967, a drillhole located on the south side of the canyon at approximately 750 metres elevation is reported to have yielded 3 per cent lead and 12 per cent zinc over 2.0 metres (silver was not assayed for; Assessment Report 16544).
In 1972, the occurrence was estimated to contain a possible 4.54 million tonnes grading 0.6 per cent lead, 2.3 per cent zinc with 7 grams per tonne silver over a 7.3 metre width, greater than 200 metres of dip length and a strike length of approximately 250 to 400 metres with indicated north plunge of 10 degrees (Assessment Report 12155, 15251, 21606).
In 1987, sampling from the south and uppermost exposure at 750 metres (high flood level of McNaughton Lake) yielded 2.1 metres grading 142 grams per tonne silver, 8.4 per cent lead and 2.0 per cent zinc, whereas some of the bands included at this location are 7 centimetres thick and yielded values of 130 to 615 grams per tonne silver, 3.5 to 5.0 per cent lead and 0.1 to 15.0 per cent zinc (Assessment Report 16544).
In 1991, chip sampling of the sulphide zone yielded 0.02 per cent zinc, 0.76 per cent lead and 24.4 grams per tonne silver (Assessment Report 22064).
In 1992, results from diamond drilling (holes TK-92-5, TK-92-8 and TK-92-12) testing the northwest extension of the zone, several hundred metres to the northwest and on the northwest side of Cummins Creek canyon, intersected a relatively thick sequence of sulphide-bearing dolomite. At best, the mineralized horizon assayed 3.58 per cent zinc, 0.84 per cent lead and 14.97 grams per tonne silver over 5.24 metres (TK-92-5) which includes 0.35 metre of 8.50 per cent zinc, 1.78 per cent lead and 24.68 grams per tonne silver (Assessment Report 22635).
In 2015, two mineralized samples (R242700 and R242698) taken from the south side of the canyon wall yielded 5.34 and 3.82 per cent zinc, 8.65 and 4.37 per cent lead with 194 and 85.6 grams per tonne silver, respectively (Assessment Report 36323).
In 2016, drilling on the northwest strike extension of the zone, approximately 600 to 1000 metres to the northwest of plotted location of the occurrence, yielded intercepts of up to 2.00 per cent zinc, 0.55 per cent lead and 11.3 grams per tonne silver over 10.1 metres (148.3 to 158.4 metres downhole) in hole CMR16-06 (Assessment Report 36408).
In 2024, a rock sample (JD06) from the main zone, exposed on the south side of the creek canyon, yielded 2.44 per cent lead, 4.77 per cent zinc and 65.7 grams per tonne silver (Assessment Report 42636).
Another zone of minor copper mineralization is reported in the Tsar Creek canyon, approximately 12 kilometres to the southeast. Mineralization comprises massive pyrrhotite with stockwork quartz veins over 4 metres of thickness in silicified massive, fine-grained metasedimentary rocks and roughly conformable with bedding. Lithological units in the Tsar Creek area correlate to those in the Cummins Creek canyon and likewise thicken rapidly downdip. In 1981, samples are reported to have averaged approximately 0.3 per cent copper (Assessment Report 09994).
Work History
In 1949, mineralization was discovered during the construction of the Big Bend Highway and subsequently staked. In the subsequent years, the original claims were allowed to lapse.
In 1966, Cominco re-staked 45 claims comprising the Ben 1-45 claim group and the following year drilled 240 metres in 13 short holes. In 1970, a program of line-cutting and soil sampling was conducted by Cominco and Laura Mines. The following year, Laura Mines conducted further diamond drilling with a total of 490 metres drilled in four holes.
Subsequent work followed and in 1979 John Leask and Associates reinterpreted the mineral occurrence to be of a shale-hosted massive sulphide type, similar to the Howard’s Pass deposits. In 1981, E & B Explorations Ltd. conducted a program of geological mapping on the area as the MGM property. In 1983, Riocanex Inc. conducted programs of ground magnetic and electromagnetic surveys and geochemical (rock and soil) sampling with minor prospecting and geological mapping on the MGM property. In 1985, Esso Minerals Canada completed two diamond drill holes, totalling 211.85 metres, immediately southwest of the Bend North Road Zone (MINFILE 083D 002) occurrence. In 1987, Cominco Ltd. conducted a program of geological mapping, rock sampling and drill site construction on the Bend 2-4 claims.
In 1990, White Knight Resources conducted a program of geological mapping on the MGM 4 claim. In 1991 and 1992, Cominco Ltd. and Teck Exploration Ltd. completed programs of prospecting, geological mapping, geochemical (soil, silt and rock) sampling, minor trenching, ground magnetic and electromagnetic surveys, historical core re-logging and 20 diamond drill holes, totalling 6093.4 metres, on the Bend and MGM groups of claims in attempts to trace the mineralized horizon northwest and southeast along strike and down dip.
In 2015, soil and rock sampling was conducted on the Cummins River property on behalf of Tsar Creek Holdings Ltd. The Cummins River claims covers the Bend Canyon Zone, the Bend North Road Zone (MINFILE 083D 002) and the Bend 2900 Zone (MINFILE 083D 015). The ground-work included the collection of 430 soil samples and 96 rock samples. Also in 2015, an airborne geophysical survey was completed on behalf of Tsar Creek Holdings Ltd. A total of 623 line-kilometres of helicopter-borne electromagnetic (VTEM) geophysical data were acquired. The following year, Tsar Creek Holdings Ltd. completed six diamond drill holes, totalling 2187.2 metres, on the property. In 2018, Tsar Creek Holdings Ltd. conducted a program of structural geological mapping on the Cummins River property. In 2023 and 2024, Tsar Creek Holdings Ltd. conducted minor programs of rock, silt and soil sampling on the Bend property.
