The Aurum or Island Mountain mine is located on the southeast slope of Island Mountain, extending from the town of Wells southwesterly along the west shore of Jack of Clubs Lake. The property is adjoined to the northwest and southeast by the Mosquito Creek (093H 010) and Cariboo Gold Quartz (093H 019) mines, respectively.
The area is underlain by a thick, highly deformed sedimentary sequence belonging to the Downey succession of the Proterozoic-Early Paleozoic Snowshoe Group. This sequence consists of quartzites, conglomerates, grits, siltstone, slates, phyllites, marbles, limestones, dolomites, amphibolites and possibly metatuff. The sequence has been folded and regionally metamorphosed to greenschist facies.
There are two types of auriferous occurrences at the Island Mountain deposit. One type consists of quartz-pyrite veins occurring in a sequence of black and grey clastic sediments that in the past has been referred to as the Rainbow Member. The ore bearing quartz veins carry up to 25 per cent pyrite and also may contain some galena, sphalerite, arsenopyrite, scheelite and cosalite. The veins represent filling of an extensive fracture system and occur in two general directions.
The other type of mineralization consists of stratabound, massive auriferous pyrite lenses referred to as replacement ore. These occur at the contacts and within certain limestone beds referred to as the Baker Member. The replacement bodies are composed almost entirely of pyrite and minor arsenopyrite. They are commonly localized in the crests or noses of minor folds and less frequently in fold troughs. Carbonate and sericite alteration is associated with the mineralization.
The adjacent Mosquito Creek mine (093H 010) produced 661,604 grams of gold from lenses hosted in a limestone unit called the Main Band (George Cross News Letter No. 55, 1989). Recent exploration at the Island Mountain mine has concentrated on this horizon. The Jukes adit, recently completed, provides access to 1000 metres of unexplored stratigraphy. A channel sample over 60 centimetres from the intersection of the Jukes adit and the old Island Mountain workings assayed 51.42 grams per tonne gold (George Cross News Letter No. 55, 1989).
At the Island Mountain mine, most of the production in early years was from quartz veins while in later years mining concentrated on the higher-grade massive lenses.
Combined reserves at the Island Mountain and Cariboo Gold Quartz (093H 019) mines are 326,556 tonnes grading 4.1 grams per tonne gold (Vancouver Stock Exchange Filing Statement 24/86, Mosquito Creek Gold Mines Company Ltd.).
A mineral inventory of 36,000 tonnes grading 24 grams per tonne gold remains in the northern extremities of the old Island Mountain workings (Property File - Gold City Mining Corporation Information Brochure).
Gold-bearing quartz veins were found on Island Mountain in the early 1870s, and in 1878 the Enterprise Company, a group of Barkerville miners, began exploration work on them. This company intended to haul ore to a 10-stamp mill installed in the Kurtz and Lane shaft-house at the Meadows. The Island Mountain Quartz Mining and Milling Company, Limited Liability, was incorporated in 1887 to take over the ground. The mill was purchased and moved from the Meadows to the Aurum N.E. claim (Lot 10518) and, assisted by a loan of $20,000 from the British Columbia Government, a new mill was built. Several hundred tons of ore, mainly from the Johns adit, was milled in 1890, and 15 to 20 tons of pyrite concentrates was shipped to the Government Reduction Works at Barkerville for treatment.
A satisfactory recovery of gold could not be made, and the property was forfeited to the Government for non-repayment of the loan. No further work was done until 1897, when the same company leased the property from the Government, installed four vanners, and ran the mill for about a month, again unprofitably. In 1903, the late C.J. Seymour Baker tested ore from Island Mountain and cleaned out some old adits, but interest in the property again lapsed.
About 305 metres of underground work was done during early exploration. Although several hundred tons of ore was milled, there is no record of the amount of gold produced.
Surface workings for the most part are on the Aurum and Aurum West mineral claims. Attention was first drawn to these outcrops by early prospectors who were able to recover gold by rocker from the broken and weathered quartz outcrops.
In 1925, Baker acquired the five original Crown-granted mineral claims, later known as the Aurum group, from the Government and each year until 1932 employed a small crew clearing out the old workings. In 1932, he optioned the Aurum group of five claims to Reward Mining Company, Limited, who located eight adjoining claims to the west. This company bonded the whole property to Cariboo Consolidated Gold Mines, Limited, in 1933; a controlling interest in Cariboo Consolidated had been acquired earlier in the year by Newmont Mining Corporation of New York. In October 1933, Newmont incorporated Island Mountain Mines Company, Limited, to acquire and develop the property, which then consisted of 29 claims. In addition to the old Union Quartz Crown grant (Lot 2B) the property comprised the Aurum, Mohawk, and Paystreak groups, and other claims, including Lots 10517, 10518, 11066-11073, 11081-11095. These claims were Crown granted to the company during the period 1935-41. Production by Island Mountain Mines began in November 1934 with a 50-ton mill. The mill capacity was increased to 100 tons-per-day in 1935 and production was continuous until August 15, 1954, when the company sold the property, excluding the mill, to The Cariboo Gold Quartz Mining Company, Limited, for $300,000.
Island Mountain Mines had developed the property from a main haulage adit, from which a 3-compartment internal shaft 442 metres was sunk; 11 levels were established from the Aurum shaft; the mine workings are extensive, totalling more than 32 kilometres.
The mine remained in production after its purchase by Cariboo Gold Quartz, the ore being hauled to the Cariboo mill some 640 metres to the east. The company's interest in the property was in part to provide access to the Mosquito group, adjoining to the northwest; the Mosquito (Lot 10355) and Mosquito Fraction (Lot 10359) had been Crown granted to Cariboo Gold Quartz in 1936. A drift to the northwest on the 3000 level was begun in 1958 to explore the Mosquito claims, some 610 to 1220 metres northwest of the Aurum shaft. This work resulted in the discovery of a number of replacement orebodies which were developed on three levels (2850, 3000, and 3125) during 1960 and 1961. Operations were continuous until the mine closed on March 31, 1967.
The Mosquito, Mosquito Fraction, and several adjacent claims (see National Mineral Inventory 93H/4, Au4) were purchased in 1971 by The Mosquito Creek Gold Mining Company Limited for a 20 per cent interest in that company. Cariboo Gold Quartz Mining Company, Limited, in June 1972 amalgamated with Coseka Resources Limited under the latter name. Coseka in February 1973 incorporated a wholly owned subsidiary, French Exploration Limited, to receive all its mineral property interests. In March 1973, French Exploration amalgamated with Wharf Resources Ltd. under the name Wharf Resources Ltd.; Coseka Resources Limited was allotted 80.4 per cent of the issued shares of Wharf Resources. A program of diamond and percussion drilling in 1980-81 was carried out mainly on the adjacent Cariboo property.
By a February 1985 agreement with Wharf Resources, Mosquito Creek Gold Mining Company Limited acquired 100 per cent interest in the property in exchange for shares of the company. In February 1986, Hecla Mining Company obtained from Mosquito an option to earn a 50 per cent interest in the property but then dropped it. In 1987, Mosquito Creek changed its name to Mosquito Consolidated Gold Mines Limited. In 1988, Lyon Lake Mines Limited optioned the property and earned 50 per cent interest after doing underground exploration. Ore driven from the Mosquito Mine property intersected Old Island Mountain drift.
In 1997, International Wayside Gold Mines Ltd. purchased the remaining 50 per cent of the Cariboo Gold Quartz mine (093H 019), the Island Mountain mine and the permitted Mosquito Creek Gold mine (093H 010) and formed the Cariboo Gold project. International Wayside formed a new company, Island Mountain Gold Mines Ltd., in May 1999.
In 2000, ten diamond drill holes, totalling 1722.9 metres, were completed on the Island Mountain occurrence. Two narrow intercepts of pyrite replacement were intersected in holes IMG2K-07 and IMG2K-03 yielding 15.0 and 13.3 grams per tonne gold over 0.6 metre each, respectively and several dolomite/ankerite-bearing quartz veins returning assays of 4.4 to 6.8 grams per tonne gold over widths up to 2.28 metres were the only significant assays reported in the program (Dzick, W. (2015-03-31): Cow Mountain NI43-101 Technical Report).
In 2001 and 2002, a further eleven diamond drill holes, totalling 1600.2 metres, were completed. Drilling by Island Mountain Gold Mines Ltd. in 2002 intersected 0.03 metre grading 19.4 grams per tonne gold, 0.30 metre grading 69.05 grams per tonne gold, in drillhole IGM02-02 and 1.8 metres grading 6.96 grams per tonne gold in drillhole IGM02-04. These intersections occur within quartz veins hosted by the Rainbow unit (Press Release - Island Mountain Gold Mines Ltd., July 16, 2002).
In 2003, programs of soil sampling, 36 trenches and 13 diamond drill holes, totalling 1375.2 metres, were completed. Drilling highlights included 7.45 grams per tonne gold over 8.46 metres, including 27.0 grams per tonne gold over 2.28 metres in hole ICM03-14 (Dzick, W. (2015-03-31): Cow Mountain NI43-101 Technical Report).
Exploration work by lsland Mountain Gold Mines Ltd. from 1999 to 2004 has included 6133 metres of drilling in 49 diamond-drill holes, trenching, and soil geochemical surveys.
The 2005 exploration program on the lsland Mountain Gold Project involved surface rock sampling, continuation of the 2004 Snapjack zone drilling plan, as well as three holes to the southwest targeting a soil anomaly delineated in 2003. Permits were also obtained for a systematic placer gold test across the large soil anomaly over the Snapjack zone. In total, 1888 metres was drilled in 15 holes and 77 surface rock samples were collected. The drilling found two zones of interest in and around the Snapjack Zone. The first zone (quartz veinlets) was intersected in drill holes IGM05-02, IGM05-05 and IGM05-06 which indicated an approximately 6 metre wide zone with an average grade of approximately 6.5 grams per tonne gold, while the second zone (5 per cent disseminated and replacement style pyrite) was intersected in drill hole IGM04-06 and returned 4.8 metres grading 6.8 grams per tonne gold (Dzick, W. (2015-03-31): Cow Mountain NI43-101 Technical Report).
In 2005, Island Mountain Gold Mines Ltd announced its plan to sell all of its tenure in the Wells-Barkerville area to sister company International Wayside Gold Mines.
In 2014, Barkerville Gold Mines Ltd. released results from complete whole-hole fire assays of 13 diamond-drill holes conducted on Island Mountain in 2003.
In 2016, Barkerville Gold Mines Ltd. initiated a Phase 1 drilling (27,131 metres by year end) at Island Mountain, site of the past-producing Mosquito Creek and Aurum (Island Mountain) mines. Previously, mining had focused on pyrite replacement deposits because of their higher grades. Phase 1 drilling deliberately tested the tenor and continuity of vein mineralization. In 2017, Barkerville Gold Mines tested for additional mineralization below the former Aurum and Cariboo Gold Quartz mines which have never been explored since mining operations ceased about 1960.
In June 2018, an updated mineral resource estimate for the combined Bonanza Ledge, BC Vein, Mosquito, Shaft, Valley and Cow deposits was reported at 8,109,900 tonnes measured and indicated grading 6.1 grams per tonne gold and 12,731,200 tonnes inferred grading 5.2 grams per tonne gold (Beausoleil, C. (2018-06-14): NI 43-101 Technical Report and Mineral Resource Estimate Update for the Cariboo Gold Project).
In 2018, Barkerville Gold Mines Ltd. completed a program geological mapping, channel, rock, soil and underground sampling and 449 diamond drill holes, totalling 128,759 metres, on the Cariboo Gold property.
In late May 2019, an updated mineral resource estimate for the combined Bonanza Ledge, BC Vein, Mosquito, Shaft, Valley and Cow deposits was reported at 13.495 million tonnes measured and indicated grading 5.6 grams per tonne gold with an additional 11.936 million tonnes inferred grading 5.0 grams per tonne gold, using a 3.0 grams per tonne gold cut-off grade (Beausoleil, C. (2019-07-11): NI 43-101 Technical Report and Mineral Resource Estimate Update for the Cariboo Gold Project).
In 2019, Barkerville Gold Mines Ltd. completed a program of geological mapping and 109 diamond drill holes, totalling 45,641 metres, on the Cariboo Gold property. Drilling highlights included 19.34 grams per tonne gold over 17.9 metres true width, 151.5 grams per tonne gold over 0.5 metres true width and 15.78 grams per tonne gold over 5.35 metres true width in hole IM-19-013 and 10.76 grams per tonne gold over 20 metres true width in hole IM-19-019 (Morgan, G.J. (2019-09-17): NI 43-101 Technical Report - Preliminary Economic Assessment of the Cariboo Gold Project).
In April 2020, an updated resource was reported for the Cariboo Gold project (Bonanza Ledge [MINFILE 093H 140], BC Vein [MINFILE 093H 139], KL [MINFILE 093H 140], Lowhee [MINFILE 093H 139], Mosquito [MINFILE 093H 010], Shaft [MINFILE 093H 006], Valley [MINFILE 093H 019] and Cow [MINFILE 093H 019] deposits) with a total of 21 441 000 tonnes measured and indicated grading 4.6 grams per tonne gold with an additional 21 649 000 tonnes inferred grading 3.9 grams per tonne gold using a 2.1 grams per tonne gold cut-off grade (Beausoleil, C., Pelletier, C. [2020-10-05]: NI 43-101 Technical Report and Mineral Resource Estimate for the Cariboo Gold Project, British Columbia, Canada).
In 2020, Barkerville Gold Mines Ltd. completed 82 diamond drill holes, totalling 25,397.7 metres, on the Cariboo Gold project. Drilling on the Shaft zone comprised at least four holes, totalling 996.0 metres.
Refer to Cariboo Gold Quartz (093H 019) for further details of the International Wayside's Cariboo Gold project which includes the Island Mountain area.