The Lumby (Chaput) deposit is located immediately to the north of Lumby.
Mineralization was noted and prospected in the early 1900s by a local teacher (called the Teacher showing). Mineralized veins were exposed in the 1960s by a logging company (the Mine showing). In 1968, underground development began and a mill was constructed. In 1971, Alberta Gypsum acquired the property and mill and undertook underground and surface exploration in an attempt to establish mineable reserves. Coast Interior Ventures acquired the property in 1974 and worked it sporadically until 1979. The mill was expanded to 150 tons capacity in 1980, but the plant was closed in 1981. In 1983, Quinto Mining Corporation purchased the property and increased the size. Geochemical and geophysical surveys were conducted and a trenching program exposed the Plateau shear zone which was sampled. In 1985, 10 reverse circulation holes were drilled and 13 holes were diamond drilled. In 1986, the Saddle Mountain portion of the property was mapped and geophysical surveys were conducted; 2700 metres of diamond drilling was completed on the Plateau shear zone. In 1987, 32 reverse circulation and 7 diamond drillholes were completed along with additional geophysical and geochemical surveys. An initial metallurgical test was completed. In 1988, a computer model was generated of the Plateau shear zone and 2 crosscuts and an exploratory drift were completed in the hangingwall. A preliminary feasibility study was conducted. In 1990, the Plateau shear zone workings were mapped and sampled. In 1992, the underground workings were re-sampled, assayed and mineralogical and metallurgical tests were done. In 1993, metallurgical testing was completed.
The area is underlain by sedimentary and volcanic rocks of the Upper Triassic to Lower Jurassic Nicola Group. At the Lumby occurrence, the rocks include argillite, siltstone, sericitic lapilli ash tuff, chloritic feldspar crystal tuff and minor phyllite. This sequence is well-bedded, gently folded about a west-northwest trending antiformal axis and crosscut by minor high-angle normal faults. A small granodiorite stock of Jurassic age intrudes the package and biotite hornfels is weakly developed in the wallrocks. The Plateau shear zone is a major west trending fault which dips about 48 degrees to the south and transects the central part of the property. A narrow north trending shear is also evident containing barren to weakly pyritic bull quartz.
Mineralization is known in two areas, the Chaput mine and the Plateau zone. Both are spatially related to the same structure, the Plateau shear zone.
The Chaput mine, at the western end of the Plateau shear zone, contains silver-lead-zinc mineralization associated with a system of quartz-sulphide veins arranged in a step-like pattern. The quartz veins occur in z-shaped dragfolds on the south limb of the west-northwest trending anticline. The veins are hosted in argillites that are bounded by felsic to intermediate lapilli and ash tuff. The veins, 0.3 to 1.5 metres wide, occur in a zone which strikes 110 to 120 degrees and dips south. The veins pinch and swell along strike and downdip. The best grades occur near the flat portions of the flexures. The sulphides are fine to medium grained and are intergrown with milky white and grey quartz. Sulphides comprise galena, sphalerite, pyrite, tetrahedrite, pyrrhotite, chalcopyrite and argentite. Chlorite, sericite and clay minerals are typical wallrock alteration minerals. Most mineralization in the Chaput mine is reported to occur below 600 metres (ASL) elevation. A diamond-drill hole intersection across a 1.0 metre (true width) quartz vein assayed 2296.76 grams per tonne silver and 2.33 grams per tonne gold (George Cross Newsletter 15, 1987). Between 1968 and 1976, 1991 tonnes of ore was mined producing 1,697,290 grams of silver, 1214 grams of gold, 654 kilograms of copper, 72,217 kilograms of lead and 50,847 kilograms of zinc.
The Plateau shear zone is located 600 metres to the east above 700 metres (ASL) elevation and is apparently along strike with the Chaput mine. The Plateau shear zone is 5 to 31 metres in width, averaging 24 metres, and occurs in argillite on the footwall contact with felsic to intermediate lapilli and ash tuffs. The zone strikes 110 to 120 degrees, dips 40 to 80 degrees south and has been traced for about 1000 metres east-west.
The mineralization has been confirmed downdip in excess of 150 metres. The enclosed quartz veins are up to 5 metres in aggregate width. In most areas within the zone, quartz veins are intensely sheared and brecciated. Gold is associated with fine to coarse-grained disseminated to locally massive pyrite, minor pyrrhotite and chalcopyrite. Sphalerite and galena are generally rare, but carry sporadic silver values. In many parts of the zone the breccia matrix contains a significant amount of carbonaceous (graphitic) material, where many of the highest gold values have been reported. Two mineralized sub-zones (Hangingwall, Footwall) within the Plateau zone have been outlined.
Estimated reserves of the Plateau shear zone are 507,920 tonnes grading 4.5 grams per tonne gold (Information Circular 1994-1, page 15).
The deposit is currently receiving attention as a graphite/ sericite/gold project by Quinto Mining Corporation. Four crosscuts have been completed across the mineralized zone which has widths up to 46 metres. The main drift, which follows the hangingwall, is now over 304 metres long, 3.6 metres wide and 3 metres high. In stope No. 3, a 22-metre high cave stope is being extracted over a 18-metre width in preparation for milling. Quinto bought a mechanical laboratory from Bacon Donaldson which is being reassembled in Lumby. A special flotation system was designed to handle the unique sericite/graphite/silica mineralization (George Cross Newsletter No.115 (June 15), 1994).
Metallurgical testing indicates that the graphite is too fine grained and too tightly bound to the muscovite to be a viable byproduct. The graphite occurs as ultra-fine grains interleaved in very fine grained muscovite/sericite. The graphite enables the muscovite/sericite to be readily floatable which may have value as a byproduct (Assessment Report 22837).
Metallurgical testing in 1993 concluded that 3 products could be extracted from the Plateau shear zone material. These are a very fine grained muscovite-graphite mix which has been termed "Schillerite No. 1", a pyrite-gold concentrate from which gold can be recovered and a very fine-grained muscovite product termed "Schillerite No. 2" (Assessment Report 23029). Unclassified reserves are 27 million tonnes of graphite (Information Circular 1994-19, page 16).
Quinto was reported to be actively sampling and evaluating the property in 1996. In May 2000, the company began processing of its graphite and sericite products.