The former Fairview mine is located 1.5 kilometres west of Burnell Lake and 6.5 kilometres west-northwest of Oliver, British Columbia. The claims (most former Crown grants) comprising the Fairview mine have changed considerably over time but have included the Buller (Lot 554s), Roberts (Lot 555s), Fairview (Lot 556s), Haligonian (Lot 557s), Western Girl (Lot 574), Comet (Lot 624), Richland Fr. (Lot 702s), Randolph (Lot 731), Shamrock (Lot 770), Gold Bug (Lot 934), Western Hill (Lot 1085), Flora (Lot 1086), Virginia (Lot 1087), Oro Basante (Lot 2055), May Queen (Lot 6895), Dalton Fr., Gold Dust Fr., Homestake Fr., Stemwinder Fr. No. 1, Stemwinder Fr. No. 2, Stemwinder Fr. No. 3, Baden Powell, Ness, John Fr., Wynn Fr., Dominion, Ada, Tenas Fr. and Black Hawk.
Regionally, the area is underlain by a northwest trending, narrow elongate belt of complexly deformed, regionally metamorphosed Carboniferous to Permian Kobau Group metasedimentary and metavolcanic rocks which separate two large intrusive bodies; the Jurassic Oliver Plutonic Complex granite to the northeast and the Jurassic to Cretaceous Fairview intrusion granodiorite to the southwest. Both plutons cut the lithologies and structures of the Kobau Group. The Kobau Group rocks comprise banded and foliated quartzitic lithologies with minor mafic schists, and thick, compositionally layered mafic schist units with intercalated quartzite bands. Minor meta-carbonates and mafic metavolcanic flows or sills occur within the quartzites and schists which have undergone at least three phases of folding and later brittle faulting. The metasedimentary-volcanic package is cut by aplite dikes, small granitic, dioritic and mafic stocks, and Tertiary northeast trending mafic dikes. Dacite dikes occur in swarms and are parallel to the regional compositional layering within the Kobau Group rocks east of the Fairview intrusion. Auriferous quartz veins occur in all lithologies but are thickest and most continuous where they occur in the quartzites. Some significant veining also occurs in the intrusive bodies. Tertiary faults crosscut all lithologies including the quartz veins.
The Fairview mine area is underlain by a northwest trending sequence of brownish and greenish grey, impure micaceous quartzite layers separated by biotite-rich layers, overlain by a mafic unit consisting of chloritic quartz-feldspar-mica schists with minor interbedded quartzose layers. A series of intermediate to felsic dikes parallel to foliation occur throughout the lower quartzite unit. Late, non-foliated Tertiary basalt-andesite dikes cut all units. The stratigraphy is tightly squeezed and strongly foliated at 100 to 130 degrees between the Oliver Plutonic Complex granite to the north and the Fairview intrusion granodiorite to the south. Dips are to the northeast at 50 to 65 degrees. Small scale isoclinal folding can be seen in the sedimentary and volcanic units as well as the quartz veins. Regional foliation (S1) which trends 130 degrees, parallels both the quartz veins and the sericite-biotite-graphite- sulphide-filled fractures commonly found within the veins. These vein fractures may represent axial planar cleavage related to the small scale isoclinal folding and regional foliation developed during emplacement of the Fairview granodiorite. A later fracture cleavage (S2), trends 000 degrees to 020 degrees and dips 50 to 70 degrees west. It is especially evident in quartz veins and is possibly related to late faulting.
Faulting of at least two separate ages is common throughout the mine area. The oldest faults parallel the regional foliation and are best developed in the area of quartz veining where they are located on both the top and bottom of the quartz veins. They are commonly graphitic, usually filled with clay and/or sand gouge and often have associated caving. Slickensides on fault planes within the quartz veins typically have a southeast plunge at 30 to 40 degrees. Direction of movement has not been determined. A large number of younger faults, possibly Tertiary in age, are common throughout the mine workings. Many of the larger faults are left-lateral reverse faults that offset the quartz veins approximately 18 metres horizontally. The vertical component of movement is unknown. The faults, like the quartz veins, have a considerable roll, often flattening substantially over short distances. Normal faults which seem to be about the same age or slightly younger than the reverse faults occur throughout the mine and may reflect a 'relaxing' of compressional forces.
Mineralization is confined to a quartz vein system which is generally conformable to penetrative fabrics developed in the Kobau Group hostrocks and display a variety of early ductile and later brittle deformation features. The vein system has been traced over 4 kilometres from the Morning Star mine (082ESW006) in the southeast through the Stemwinder mine (082ESW007) to the Fairview. The veining consists of two dominant veins often with a third or fourth present. They occur in the lower quartzite sequence, usually within 60 metres of the Fairview granodiorite contact. Individual veins reach up to 15 metres thick and pinch and swell both along strike and downdip.
Fluid inclusion and stable isotope studies at the Fairview occurrence indicate mesothermal fluids were responsible for mineralization events. The fluids are characterized by a high carbon dioxide content, temperatures of 280 to 330 degrees Celsius, salinities of 4 to 6 weight per cent NaCl and oxygen del 18 values of 4 to 6 per mil (relative to standard mean ocean water). The mineralization occurred at depths of 3 to 4 kilometres.
Three veins occur on the Fairview property and are reported as the North, Main and South veins. The veins strike 290 to 315 degrees and appear to be closer together in the southeast.
The South vein outcrops in the southeast corner of the Comet, extending across the Flora and Western Hill claims and is believed to persist across the Virginia, Buller and Fairview claims. The vein has been developed by approximately 496 metres of underground and surface development.
The Main vein enters the Comet claim from the neighbouring Stemwinder property (082ESW007) and extends 60 metres or more into the northeast corner of the Comet claim and further to the northwest into the Western Girl and Wynn Fr. claims.
The north vein traverses the Brown Bear, Stemwinder, Tenas Fr. Wynn M. claims (082ESW007), Wynn Fr. and Oro Basante claims. On Level 6, in the Fairview mine, two quartz veins are exposed; the Hangingwall vein (HW vein and/or North vein) averages 2.5 metres and the Main vein (MV) averages 2.0 metres. The veins are roughly parallel, strike northwest and dip 45 to 55 degrees to the northeast and are separated by 10 to 15 metres of foliated quartzite. Several high-grade shoots occur within these veins. Gold and silver values occur in portions of the vein that contain up to 2 per cent which include pyrite, sphalerite, galena and chalcopyrite. Strong fracturing parallel to foliation with graphite, sericite, chlorite and biotite fracture-fillings accompanies the mineralized zones. Faulting parallel to the quartz vein zone may account for the rapid thickening and thinning of the veins. Within the sulphide enriched area, ore shoots up to 82 metres long and 1.8 metres wide have been identified.
Gold and silver values are closely associated with the presence of galena with or without chalcopyrite, sphalerite or pyrite. Sulphide mineralization appears to be of two ages and three styles. Galena, chalcopyrite, sphalerite and rare pyrrhotite are fracture- controlled with most occurring along S1 fractures in quartz veins. A very small percentage also occurs along S2 fractures. In places, massive pyrite or galena forms irregular clots up to 20 centimetres across. For the most part, the best galena-chalcopyrite-sphalerite mineralization and highest gold and silver values occur in the hangingwall parts of the veins, although significant values have been obtained throughout the vein. Gold values are higher where the vein has well developed S1 fractures lined with sericite-biotite- chlorite-graphite and sulphides.
Preliminary lead isotope studies indicate the mineralization is associated with quartz veins is younger than or as young as the Oliver pluton (circa 155 Ma) (Fieldwork, 1988, pages 19-25). The following mineralizing sequence has been proposed: emplacement of the Oliver Plutonic Complex in Late Jurassic producing local penetrative fabric and a contact metamorphic aureole, emplacement of the Fairview pluton in Cretaceous resulting in the tight folding of Kobau Group stratigraphy producing a well developed foliation and small-scale isoclinal folding, shearing along the upper contact of the Fairview pluton, continued movement along shears and mobilization of metals along late vein-parallel fractures, and Tertiary faults cutting and offsetting mineralized quartz veins.
Past and present work consists of extensive underground development which commenced in 1888 by the Dominion Consolidated Mines Co. Ltd. By 1900, the workings included a 366-metre adit and 30 metres of shafts and drifts. Mill tests on ore were carried out at the Stemwinder mill (082ESW007) in 1903. The property was acquired by Fairview Amalgamated Gold Mines, Ltd. in 1933. The Flora lower adit and No. 1 adit were developed by over 305 metres of drifts, crosscuts and raises between 1933 and 1935. In 1936, the Fairview and Morning Star properties were amalgamated and ore was milled at a new mill on the Morning Star property (082ESW006). All work ceased in September 1939.
Kelowna Exploration Co. Ltd. held an option on the property in 1944 and carried out an assessment of the property. In 1946, the Consolidated Mining and Smelting Co. of Canada Ltd. purchased the property and resumed mining of the quartz veins as a source of flux for the Trail smelter. Mining from the No. 6 Level was continuous until 1961. The majority of mine workings were developed on the Comet, Western Girl, Flora, Western Hill, Oro Basante, Virginia and Fairview claims. In 1986, Oliver Gold Corp. optioned the Fairview and Morning Star (082ESW006) properties from Cominco Ltd. In the following year, an extensive exploration program was concentrated on the workings of the former Fairview mine. The Nos. 3, 5 and 6 levels were re-opened and underground diamond drilling, sampling and geological mapping were carried out. A preliminary feasibility assessment was made and metallurgical testing was initiated.
Past production data for the former Fairview mines is incomplete. It is reported that 440,109 tonnes of ore were mined between 1892 and 1961 from the Western Girl (Lot 574), Western Hill (Lot 1085), Flora (Lot 1086), Virginia (Lot 1087) and Oro Basante (Lot 2055) claims with an average grade of 3.84 grams per tonne gold and 48.00 grams per tonne silver (Valhalla Gold Corporation (1988): Prospectus). These production figures could not be confirmed. Ministry production records indicate production from 1937 to 1939 totalled 88,640 tonnes, resulting in 3,774,816 grams of silver, 285,215 grams of gold, 9087 kilograms of copper and 75,221 kilograms of lead recovered. From 1946 to 1961, when mining ceased, the veins were mined as a source of silica flux for the Trail smelter. A total of about 333,607 tonnes of silica were produced.
An ore reserve estimate by Cominco on the Fairview property was 762,000 tonnes of undiluted combined ore reserves (measured (38 per cent), indicated (11 per cent), and inferred (50 per cent)), grading 3.77 grams per tonne gold and 41.14 grams per tonne silver (Valhalla Gold Corporation (1988): Prospectus). Several higher grade ore shoots were outlined by Oliver Gold Corp., extending from the No. 3 level downward over 183 metres elevation to the No. 6 level. The two high-grade zones contain a possible 100,000 tonnes of ore with grades better than 10.28 grams per tonne gold 68.57 grams per tonne silver (Valhalla Gold Corporation (1987): Prospectus). Drilling also established the continuity of ore underneath the No. 6 level, ranging from 3.08 to 3.77 grams per tonne gold (Valhalla Gold Corporation (1987): Prospectus). The widest intersection was over a true width of 12 metres.