The Spyglass occurrence is located at an elevation of 1765 metres, near the head of Poplar Creek and approximately 2.5 kilometres southwest of Spyglass Mountain in the Slocan mining division.
Regionally, the area lies within the Selkirk Mountains of south eastern British Columbia. The occurrence is within the Kootenay Arc, a curving belt of highly deformed metasedimentary and metavolcanic rocks that includes the upper Proterozoic Horsethief Creek Group, the upper Proterozoic to lower Cambrian Hamill Group, the lower Cambrian Badshot Formation, and the Paleozoic Lardeau and Milford groups. The volcano-sedimentary sequence is intruded by numerous Paleozoic to Mesozoic granitoid plutons.
The Spyglass Mountain area is mainly underlain by limestone, slate, siltstone and argillite of the Upper Mississippian to Permian Milford Group and basaltic volcanic rocks of the Carboniferous to Permian Kaslo Group. The layered sequence is tightly folded in a series of northwest- trending folds, which are cut by quartz monzonite intrusive rocks of the Middle Jurassic Kuskanex Batholith. The rocks have undergone contact and regional metamorphism to middle or upper greenschist facies (Geological Survey of Canada Bulletin 193).
The Spyglass occurrence consists of a quartz vein striking 150 degrees and dipping 50 to 60 degrees southwest, parallel to the schistosity of the enclosing phyllite, quartzite, limestone and argillite. The vein has an average width of 60 centimetres and has been traced, intermittently, for approximately 750 metres in underground and surface workings. Mineralization, which consists of primarily pyrite, galena and tetrahedrite with minor chalcopyrite, pyrrhotite and sphalerite is unevenly distributed and does not appear to extend the entire length of the vein. Sericite and chlorite alteration are also reported.
A grab sample of the mineralized quartz vein assayed 1.3 grams per tonne gold, 7572 grams per tonne silver, 3.68 per cent copper, 23.1 per cent lead and 5.8 per cent zinc (Minister of Mines Annual Report 1928).
In 1966, a sample (60399) from the upper adit assayed 2.4 per cent copper, 7.9 per cent zinc, 34.3 per cent lead, 11 ,436 grams per tonne silver and 3.4 grams per tonne gold, whereas a sample (87801) from a surface exposure above the upper adit yielded 0.2 per cent zinc, 44.7 per cent lead, 20.1 per cent bismuth, 10,608 grams per tonne silver and 20.5 grams per tonne gold (Property File - Cominco Ltd. [1966-09-26]: Assay Certificate - No. 8054 - Spyglass).
In 1968, channel sampling yielded up to 13,393 grams per tonne silver over 30 centimetres (sample 711) from the main adit; 7842 grams per tonne silver over 70 centimetres (sample 713) also from the main adit; 6089 grams per tonne silver over 30 centimetres from the up-raise (sample 714); 1493 grams per tonne silver (sample 718) from the top adit and 92.3 grams per tonne silver over 1.5 metres from the stream tunnel (Property File - J.A. Mitchell [1968-07-31]: Report on Spyglass Group - Poplar Creek)
During the early 1900’s, the vein was developed by two adits or tunnels, 15 and 75 metres long, and a small raise connecting the upper two adits. The second adit is located 30 metres below the upper adit. Another tunnel or adit is reported approximately 300 metres down slope, near the river.
In 1968, the area was examined by J.A. Mitchell. In 1979, Dekalb Mining completed six diamond- drill holes, totalling 260.0 metres. This work is reported to have failed to intersect any economic mineralization from the vein, but no assays were reported (Assessment Report 7650).
