The Bend 2900 occurrence is located on the southeast slope of the Cummins River canyon, approximately 112 kilometres south-southeast of Valemount. The showing is approximately 300 metres southeast along strike from the Bend 1 Canyon Zone occurrence (MINFILE 083D 001) and is one of four described massive sulphide outcrops occurring at consecutively higher elevations beginning at 750 metres.
Regionally, a sequence of quartzites, carbonates and pelites of the Neoproterozoic (Hadrynian) Miette Group through the Lower Cambrian Gog Group through to the Middle Cambrian Chancellor Group makes up the rocks of the Southern Park Ranges in this area. Individual beds generally strike 290 degrees and dip 55 degrees northeast. For a more comprehensive description of the regional geology refer to the Bend 1 Canyon Zone occurrence (MINFILE 083D 001).
Stratiform mineralization at the Bend 2900 occurrence is hosted within the Middle Cambrian Tsar Creek Formation of the Chancellor Group. The occurrence consists of five bands of massive pyrite, sphalerite, galena and magnetite alternating with siliceous sulphide layers. Sulphide mineralization alternates with layers of manganiferous dolomite containing lenses of massive pyrite, sphalerite and galena. The zone is approximately 5 metres thick. The southern edge of the mineralization is in contact with micaceous quartzite containing disseminated and podded pyrite, pyrrhotite, sphalerite and galena.
Other mineralized outcrops were discovered at 792, 823, 914 and 1067 metres elevation, along strike. These outcrops are considered here to be part of the Bend 2900 showing. These newly discovered occurrences extend southeast of several known stratiform exhalative massive sulphide showings including the Bend 1 Canyon Zone and the Bend North Road Zone (MINFILE 083D 002) forming a west-northwest–trending zone almost 330 metres long and approximately 60 metres wide on the north side of the Cummins River canyon.
In 1987, selected bands of the massive sulphide mineralization from the lower (main) zone assayed 0.432 gram per tonne gold, 40.69 grams per tonne silver, 4.1 per cent lead and 10.0 per cent zinc, whereas a weighted average of a chip sample over 4.7 metres from all five bands of massive sulphide mineralization assayed 12.9 grams per tonne silver, 1.2 per cent lead and 4.5 per cent zinc (Assessment Report 16544). A highly oxidized sample from 792 metres elevation, 70 metres along strike from the Bend 1 Canyon Zone, assayed 34.0 grams tonne silver, 1.2 per cent lead and 2.2 per cent zinc (Assessment Report 16544). Rubbly outcrop of manganiferous dolomite from 823 metres elevation assayed 21 to 87 grams per tonne silver, 1.1 to 4.5 per cent lead and 7 to 16 per cent zinc over less than 1 metre (Assessment Report 16544). At 914 metres elevation, small rods of fine lenses of pyrite, sphalerite and galena were noted in sericitic schist. A few mineralized quartz-filled fractures were found in a small oxidized zone within manganiferous dolomite exposed at 1067 metres elevation, approximately 300 metres southeast along strike from the Bend 1 Canyon Zone.
In 1991, three diamond drill holes (C91-1 to C91-3) were collared to the south-southwest of the Bend 2900 occurrence to test the downdip extensions of the zone. Intersections included 0.77 per cent lead, 2.40 per cent zinc and 11.9 grams per tonne silver over 5.48 metres (294.22 to 298.70 metres downhole) in hole C91-1; 0.54 per cent lead, 2.55 per cent zinc and 10.6 grams per tonne silver over 11.2 metres (252.2 to 263.4 metres downhole) in hole C91-2; and 0.31 per cent lead, 1.84 per cent zinc and 7.5 grams per tonne silver over 3.5 metres (336.9 to 340.4 metres downhole) in hole C91-3 (Assessment Report 21606). The hole C91-3 intersection is approximately 100 metres higher than projected and indicates either a fold or a fault. The increased thickness of overlying quartzite (chert) and manganiferrous dolomite in hole C91-2 possibly indicate the start of an isoclinal fold between the two holes rather than a fault.
Also at this time, four diamond drill holes (TK-91-1 to TK-91-4), totalling 1873.8 metres, were collared several hundred metres to approximately 1 kilometre to the south-southeast of the Bend 2900 zone to test the strike the extension of the zone. Intercepts included 0.93 per cent lead, 2.45 per cent zinc and 14.4 grams per tonne silver over 2.7 metres (269.0 to 272.0 metres downhole) in hole TK-91-1; 3.06 and 0.45 per cent lead, 4.44 and 2.01 per cent zinc with 34.6 and 9.3 grams per tonne silver over 0.4 and 1.3 metres, respectively (332.3 to 332.7 metres and 387.1 to 388.4 metres downhole, respectively) in hole TK-91-3; and 0.76 per cent lead, 5.82 per cent zinc and 8.0 grams per tonne silver over 0.5 metre (441.3 to 441.8 metres downhole) in hole TK-91-4 (Assessment Report 22149).
Work History
The mineralization was discovered in 1987 by Cominco Ltd. during an access road and drill site construction project. In 1991, Cominco Ltd. and Teck explorations completed program of geological mapping, soil sampling and seven diamond drill holes, totalling 2940.7 metres, on the area.
See the Bend 1 Canyon Zone occurrence (MINFILE 083D 001) for a complete work history of the area and associated mineral occurrences.
