The Dome Mountain occurrence is located on Dome Mountain about 38 kilometres east of Smithers.
The Dome Mountain vein occurrence is located on the eastern limb of a southeast plunging open anticline and cuts across a thick sequence of amygdaloidal flows and lapilli tuffs of the Lower-Middle Jurassic Nilkitkwa Formation (Hazelton Group). Rocks in the hangingwall are sericitized near the vein and grade outward into strong chlorite alteration with local concentrations of epidote, quartz, carbonate and pyrite. Footwall rocks are generally less altered. Alteration varies both in thickness and intensity and in general, gold mineralization and intensity of alteration as positively correlated. Prospectors first staked claims on Dome Mountain in 1914 to cover several showings of gold-bearing quartz veins.
The quartz-carbonate vein averages about 2.7 metres in width and has a sharp footwall contact that appears to be sheared with associated gouge development. The vein is coincident with a narrow, weakly developed zone of bleached volcanic rocks. The hangingwall contact is gradational with a zone of pervasive sericite alteration that extends several metres into the wallrock. Both barren and galena-sphalerite bearing quartz stringers occur within this altered zone. Quartz stringers, with or without carbonate stringers, are common within the chlorite altered volcanic rocks away from the main vein.
Sulphide minerals in the Boulder vein constitute approximately 10 per cent of the vein mineralogy. In decreasing order of abundance the sulphide minerals are: pyrite (6 per cent), sphalerite (2.5 per cent), chalcopyrite (1 per cent), and galena-tetrahedrite-arsenopyrite (less than 1 per cent). Pyrite occurs are fine euhedral cubic crystals disseminated throughout the wallrock alteration and quartz veins. Coarse masses of pyrite also occur as well as some individual pyrite crystals up to one centimetre wide. Often, the pyrite crystals show evidence of crushing with the interstices filled with other sulphides. Aggregates of fine grained reddish brown sphalerite occur as irregular masses associated with pyrite, galena, chalcopyrite and arsenopyrite. Chalcopyrite is commonly intergrown with pyrite. Fine-grained tetrahedrite, galena and arsenopyrite occur as disseminations, as thin fracture coatings, or as fine irregular masses with the other sulphides.
The Boulder vein and an associated splay are well defined along a 150 metre exploration drift completed in 1987. The vein strikes east and dips between 40 to 60 degrees south. It is a brecciated to massive quartz-carbonate vein cut and offset by several shear zones that have a similar trend to it. The vein pinches and swells from thicknesses of less than 1.0 metre to about 15.0 metres. Sulphide minerals occur in fractures or form massive banded concentrations within the quartz vein. Higher grade sections host semi-massive to massive concentrations of sulphides with coarse grained crystal aggregates, fracture fillings and disseminations. Gold occurs as fine grains along pyrite boundaries or is disseminated in quartz-carbonate micro-veinlets.
The Boulder Creek vein extends southeastward into the Argillite zone which comprises an irregular network of auriferous quartz veins within argillite of the Nilkitkwa Formation. This zone is at a higher stratigraphic level than Boulder Creek but the zones are mineralogically similar with the best gold grades occurring where the quartz veins contain sphalerite and galena.
The Crown-granted claims of the Dome Mountain property lie in two groups, the Pioneer-Ptarmigan group (Lots 2891-2897) on the upper north slope of the Mountain, and the Snowdrop, Bullion, and Homestead groups (Lots 2900-2922) lying on the southeasterly slope of the Mountain; the Free Gold property is located about 1500 metres to the northeast. A number of claims were staked prior to 1915 and yearly assessment work carried out. Three groups, the Bullion, Pioneer, and Homestead, comprising 14 claims, were owned by G. Hazelton, J. Probendite, J. Bourgone, and T.J. Thorpe. Work to 1918 was done in open cuts and 3 short adits. The adjoining Edith claim, owned by Chisholm and Young, was developed by a 9-metre shaft (Chisholm shaft).
In subsequent years, many of the above claims were allowed to lapse and were re-staked under new names. During the winter of 1921-22, options were acquired on all the important claims by T.E. Jefferson for a New York syndicate. Work during 1922 included stripping, trenching, and sampling of the many showings. Early in 1923, the combined property was purchased by another New York syndicate, this one financed by Guggenheim capital, and management of the property was placed under the Federal Mining and Smelting Company, which was owned by the Guggenheim interests. Dome Mountain Gold Mining Company, Limited was incorporated in March 1923 to develop the property. Work was carried on until June 1924 when all equipment was removed and the mine closed. On the Forks showing, a shaft was sunk to 32.6 metres, a crosscut was driven to the vein on the 30 metre level, and "several hundred feet" of drifting carried out. On the Cabin showing, a crosscut was driven 107 metres to the vein. A drift adit was driven for 75 metres on the Snowdrop claim. On the Ptarmigan claim, an adit was driven 122 metres.
Thirty-four claims (Lots 2888-2897 and 2899-2922) were Crown granted to the company in 1925. No further work was reported and the company charter was surrendered in 1948. The claims were transferred to Karl J. Springer in December 1950. In 1973, D.W. Coates optioned the Crown-granted claims from Springer. During the year, limited geophysical and geochemical surveys (156 soil samples) were carried out. In 1979, the No. 6 (Lot 2905) and No. 2 (Lot 2909) claims were owned by W.F. McGowan and A. L'Orsa; geological mapping was reported.
Panther Mines Ltd. and Reako Explorations Ltd., by a January 1980 agreement, optioned a 50 per cent interest each in 12 claims from Lorne B. Warren, of Smithers. Included were six Reverted Crown grants: Hawk (Lot 2888), Snowdrop (Lot 2904), No. 1 (Lot 2908) , No. 4 (Lot 2914), Wallace (Lot 2911), and Wallace Fr. (Lot 2920) , and the Dome 1-6 located claims (Record Nos. 1623-1628); trenching was reported on the Hawk claim (Lot 2888).
In 1984, Noranda Exploration Company, Limited consolidated all the original properties on Dome Mountain, except the Free Gold property, by way of a May 1984 option agreement with Panther and Reako for an 80 per cent interest in 44 claims in two groups, formerly held by Silver Standard Mines and McIntyre Mines, and a July 1984 agreement with L'Orsa et al. on 16 claims. Work by Noranda in 1984 included a geochemical soil survey and Noranda, later in the year, gave an option on its interest in the property to Canadian-United Minerals Inc. Work in 1985, with Noranda as operator, included trenching, and 1564 metres of diamond drilling in 33 holes on the Forks showing (093L 022); this work indicated 91,000 tonnes at 19.2 grams per tonne gold (George Cross News Letter No. 240, 1985). The option agreement was renegotiated in November 1985 to allow Canadian-United to earn a 50 per cent interest in Noranda's option and to become operator.
In December 1985, Canadian-United optioned a 75 per cent interest in its agreement with Noranda to Teeshin Resources Ltd.; property ownership at that point was Reako and Panther at 10 per cent each, Noranda at 40 per cent, Canadian-United at 10 per cent, and Teeshin at 30 per cent. Drilling of a geochemical soil anomaly in 1986 led to the discovery of the Boulder Creek zone (093L 276) some 350 metres north of the Forks showing. An extensive drilling program consisting of 48 holes at the Boulder Gold zone was conducted. Three additional holes were then drilled on the Forks Gold zone. They also followed up on Noranda's geochemical/geological program with two holes on the Hawk-Gem vein zone and three to four holes on the Jane vein zone. Drilling by both Noranda and Canadian-United-Teeshin outlined gold resources on the Forks Gold zone and on the Boulder zone and intersected a number of narrow high-grade veins on the Hawk-Gem and Chisholm-Jane Vein zones.
A preliminary calculation of grade and tonnage of the zone returned 218,000 tonnes grading 15.57 grams per tonne gold and 79.6 grams per tonne silver (Property File Rimfire - Canadian-United Minerals, 1986).
Another source reported drilling to June 1986 gave an indicated 453,000 tonnes at 16.2 grams per tonne gold in the Boulder Creek zone (Teeshin Resources, Corporate Update, July 15, 1986).
In October 1986, Total Erickson Resources Ltd. acquired an option on Noranda's 50 per cent back-in option and an option to earn a 64 per cent interest in Canadian-United Minerals Inc. In 1987, some 513 metres of drifting and 230 metres of raising was done in an adit at 1370 metres elevation on the Boulder Creek zone; diamond drilling was reported in the adit and on other zones on the property. Mineable reserves in the Boulder Creek zone were reported as 290,000 tonnes with an average diluted grade of 12.7 grams per tonne gold and 68.6 grams per tonne silver (Total Erickson Resources Ltd., 1987 Annual Report).
The Boulder ore zone averaged 2.5 metres in width and was traced over a strike length of 350 metres. Noranda drilled 58 holes on the western and eastern extensions of the Boulder Gold deposit. Drilling was concentrated on the eastern extension on the Argillite Gold zone. A bulk sample of 5000 tonnes taken in 1985 and processed at the Premier Stilbak mill averaged 27 grams per tonne gold and 42.8 grams per tonne silver (as reported in Assessment Report 28891). After the bulk sample, limited mining had taken place before financial tribulations forced cessation of mining. However, before the closure of the mine in 1992, drilling along the western extent of the Boulder structure revealed that the Cabin vein is a continuation of the Boulder Gold deposit. The Cabin vein is very close to the Guardsmen property boundary. This westerly trend can clearly be traced on surface for about 500 metres up to the Creek Vein zone well within the Guardsmen's property.
The Forks Gold deposit is located 500 metres south of the Boulder Gold deposit. The Forks Gold deposit consists of two veins that are found to be striking west-southwest and dipping at a shallow angle towards the Boulder structure. From 1985 to1987, a total of 23 diamond-drill holes on the Forks Gold deposit outlined a resource of 20,000 tonnes at a grade of 23.6 grams per tonne gold. The Forks Gold deposit is a flat lying, extremely sheared and altered quartz breccia vein structure with a thickness of up to 12 metres. Drilling in 1987 intersected intervals up to 7.6 metres grading 10.42 grams per tonne gold and 53.38 grams per tonne silver. The highly altered vein structure is open along strike. Further detailed mapping and drilling may prove that the Forks structure may be related to the Hoopes breccia to the west.
In 1989, Teeshin Resources Limited reported mineable reserves of 271,800 tonnes at 12.21 grams per tonne gold. Teeshin conducted a 26.9 kilometre induced polarization (IP) survey. The primary objective of the IP survey was to map the extent of the Boulder zone (quartz/sulphide vein system), and to search for similar targets in the survey area.
Diamond drilling of eight holes in 1990 added another 21,700 tonnes of similar grade material to the reserves. This work was centred on the Boulder zone, and proved the zone was not closed off but continued on an easterly down plunge. Other areas explored on the Teeshin property included the Forks zone (093L 022), the Elk vein (093L 275) and the 9800 zone (093L 277) (Property File Placer Dome - Smit., 1990). In 1990, the total diluted proven and probable mineable ore reserves, at a 20 per cent dilution rate, on the Dome Mountain property were 294,545 tonnes at an average grade of 12.17 grams per tonne gold and 80.66 grams per tonne silver (Property File Placer Dome - Teeshin Resources Ltd., 1990).
In 1991, Teeshin formed a joint venture with Timmins Nickel Inc. Teeshin changed its name to Hapsburg Resources Inc. Mining commenced on the Boulder vein and ore was shipped direct to the Equity Silver mine mill (093L 001). The 1290 crosscut was started. In 1991, ore mined (5079 tonne bulk sample) from the upper level of the Boulder zone was sent in two lots to the Equity Silver mine and the Premier mine (104B 054) to test for cost effectiveness of milling. Recoveries from the initial 3205 tonnes of ore custom milled at the Premier mine mill were 86,179 grams of gold and 136,982 grams of silver. The operator of the mine (Timmins Nickel) has reported development will allow a production rate of 4535 to 5442 tonnes-per-month at an anticipated grade of 17.14 grams per tonne gold (George Cross News Letter No.6, 1992).
In early 1992, seven NQ diamond-drill holes totalling 546 metres were drilled on the Cope 1 claim on Dome Mountain. Drilling was targeted on the Boulder Shear. The best intersection was 4.8 metres grading 27.02 grams per tonne gold (Assessment Report 22567). A Mining Lease was approved and the mine operated with 28 employees. A second portal has been collared at the 1280-metre level approximately 500 metres to the east of the existing portal at the 1370-metre level. In, 1993, mining was suspended due to Timmins' financial and legal problems. In 1994, Hapsburg Resources Inc. changed its name to Dome Mountain Resources Ltd. In 1994, in situ possible, probable and proven reserves of the Boulder and Argillite veins were 200,768 tonnes grading 14.9 grams per tonne gold with a cut-off grade of 10.2 grams per tonne gold and the minimum mining width is 1.6 metres (horizontal) and 2.0 metres (vertical) (George Cross News Letter No.68 (April 11), 1994).
In 1996, Dome Mountain Resources Ltd. changed its name to DMR Resources Ltd (DMR). In 2001, DMR is delisted. In 2001, Guardsmen Resources conducted a limited exploration program on the northwestern section of their claim block. This area is centred on the Gem-Ptarmigan vein area approximately 2500 metres northwest of the Boulder Gold deposit area. Guardsmen had hired J.L. Gravel, of Prime Geochemical Methods Ltd., as well as geologists F. Childe and A. Kaip to conduct geochemical and lead-isotope studies, respectively. The lead-isotope study concluded that the mineralization at Dome Mountain is relatively close in age to that of Eskay Creek (104B 008), although the style of mineralization found at Dome Mountain to date is incomparable to Eskay Creek. Guardsmen was encouraged to commission the study as the southern flank of Dome Mountain contains Bowser Lake sediments and the Ascot (093L 024) is a volcanogenic massive sulphide (VMS) prospect.
In 2000, Guardsmen established a geochemical sampling grid over an area measuring 500 by 700 metres situated south of the Ptarmigan (093L 285), Gem (093L 285) and Eagle (093L 284) vein area. Soils were also collected over the Jane showing grid, the Telkwa showing grid and the North Betty Creek showing grid. A total of 388 soil samples were taken in addition to 112 rock samples and 29 stream silt samples. The soil sampling program showed strong gold anomalies over the three known veins, Ptarmigan, Eagle and Gem. There were also two strong linear gold geochemical anomalies parallel to the known veins. The gold soil geochemical anomalies have strike lengths of 400 to 700 metres and are open to the northwest and southeast. The northwest trending Gem - Ptarmigan veins are typically 30-60 centimetres in thickness and are hosted by sheared and altered andesitic tuffs of the Hazelton Group. Zones sampled included: Gem (093L 285), Raven (093L 281), Ptarmigan (093L 283), Jane and Chisholm (093L 279), Hawk (093L 282), Cabin (093L 275), 9800 (093L 277), Forks (093L 022), Marjorie, Old Trench, Telkwa, North Betty, and Creek.
In 2005, DMR, transferred ownership of the Mining Lease and their remaining claims to Angel Jade Mines Ltd., K. Coswan, A. L'Orsa and J. L'Orsa (L'Orsa-Coswan-Angel Jade).
In 2006, operator Christopher James Gold Corporation collected 68 rock samples in total from 12 different zones including Gem (093L 285), Raven (093L 281), Ptarmigan (093L 283), Jane and Chisholm (093L 279), Hawk (093L 282), Cabin (093L 275), Hoopes (093L 280), Free-Gold (093L 023), Marjorie (undocumented) and South (undocumented). In 2007, Christopher James Gold Corporation prospected and conducted soil geochemical surveys at its Dome Mountain (093L 277) and Happy Sullivan gold properties. A new copper-silver-barite occurrence, the Peggy showing, was found on Dome Mountain. In 2007, Eagle Peak Resources Inc. optioned the property from L'Orsa-Coswan-Angel Jade.
In 2008, Eagle Peak Resources reopened two portals, three air vents and the mine access road, and completed a 22 kilometre IP survey. Eagle Peak Resources intends to validate an historic resource and then to re-open the mine for production. In 2008, the company collected soil sampling over a grid that covered (Dome Mountain (093L 276), Dome Mountain- Forks (093L 022) and 9800 (Dome Mountain) (093L 277). An IP survey was conducted over 22 kilometres and ground magnetic survey over 23.1 kilometres.
In 2009, Eagle Peak Resources Inc. propose to re-open through an affiliated company, Metal Mountain Resources Inc. In 2009, 888.2 metres were drilled in four diamond-drill holes on the Boulder vein system. In 2010, Metal Mountain Resources Inc. began development of the Dome Mountain underground mine through its wholly-owned subsidiary Gavin Mines Inc. In 2011, Metal Mountain Resources Inc. continued development of its Dome Mountain underground gold-silver mine. Seven hundred tonnes of ore are ready to be shipped with full-time production awaiting installation of an additional vent raise. Underground development is focussed on reopening the 1290 and 1370 metre levels built in 1991. The Boulder and Boulder footwall veins (93L 276) are current mine targets and contain a probable mineral reserve (including dilution) of 135,131 tonnes grading 11.2 grams per tonne gold at a diluted cut-off grade of 7.9 grams per tonne gold. The undiluted indicated resource is 144,144 tonnes grading 17.7 grams per tonne gold at the same cut-off. The inferred resource is 113,671 tonnes at 13.6 grams per tonne gold (Exploration in British Columbia 2011).
In 2012, despite substantial efforts including shipping of approximately 5000 tonnes of ore, a long term arrangement could not be reached with off-site mill operations. Underground development in early 2012 advanced workings to the first cut and fill stope on the 1290 level and produced 1385 tonnes from the Boulder vein. Other underground activities included vent raise development and diamond drilling. Surface activities involved completion of additional site infrastructure. A soil sampling program over the Chance (093L 278) and Free Gold (093L 023) occurrences and the area between, resulted in the collection of 745 samples. In 2013, Metal Mountain Resources Inc., wholly owned subsidiary Gavin Mines Inc., continued preparation towards mine development given amended permitting.
In 2015, corporate negotiations continue between Metal Mountain Resources Inc., Gavin Mines Inc. and Grace Mining Inc. Over the winter months, an infill drill program will aim to define additional inferred resources and extend the mine life to 7 years. Drilling targets include near-mine extensions of the Boulder vein as well as deeper drilling on the Argillite vein.
Activities on the property in 2016 included diamond drilling, underground geological mapping, and preparation to resume mining. A diamond drill program completed over the 2015-16 winter totalled 6954 metres in 35 holes. The drilling increased an in-house resource estimate that suggests the mine life could be extended past its current 5 year plan. Current resource estimates (Measured plus Indicated) are 144,144 tonnes at 17.7 grams per tonne gold (Information Circular 2016-1, page 12).
The Dome Mountain deposit consists of two principal zones of gold-silver mineralized structures named the Boulder and the Argillite veins. Both occur in folded fragmental rocks and invariably altered, amygdaloidal basaltic andesite. The Boulder vein varies from 0.7 to 4.5 metres wide and has subparallel hangingwall and footwall veins. Known strike length is approximately 700 metres and may extend westward. The Argillite vein varies from 0.7 to 4.75 metres wide and has a known strike length of about 200 metres. The mineralized vein systems are primarily composed of quartz with lesser calcite and ankerite. They are typically only gold bearing when sulphide minerals are present. Quartz occurs as both as an opaque, massive variety and a clear variety that is associated with higher gold grades. Sulphide minerals include pyrite, sphalerite, chalcopyrite, galena, tetrahedrite, and arsenopyrite. Visible gold is rare. Native gold and electrum occur as micro-scale fracture fills in pyrite and along grain boundaries.
In 2017, Gavin Mines Inc., a subsidiary of Metal Mountain Resources Inc., owns 54 per cent. Grace Mining Inc. owns 30 per cent, Dome Mountain Resources of Canada Inc. owns 14 per cent and two private shareholders own 2 per cent. Gavin Mines Inc. continues to work towards restarting the historic Dome Mountain gold and silver mine. The project has current Mines Act and Environmental Management Act permits in good standing and is allowed to excavate up to 75,000 tonnes-per-year. In early 2013, the project submitted applications to amend their existing Mines Act and Environmental Management Act permits that would allow for onsite milling and tailings storage. Due to various delays, including regulatory changes due to the 2014 Mount Polley tailings breach, the permit amendments remain outstanding. In 2016, stockpiled material was processed at Nicola Mining Inc.’s custom mill facility near the town of Merritt. In February of 2017, the company reported that a longer term profit share agreement with Nicola Mining was being negotiated.
Nicola Mining operates a 200 tonnes-per-day custom mill near Merritt and uses tailings storage built for the past-producing Craigmont mine. The mill was originally constructed to process ore from the Treasure Mountain mine, which operated in 2013. The operation was recently upgraded with a gravity jig and concentrating table for processing free gold. In 2017, it underwent modifications and continues to process gold-silver ore from the Dome Mountain mine under a contract with Metal Mountain Resources Inc.
In July 2020, Blue Lagoon Resources Inc. reported an updated undiluted mineral resource of 173 471 tonnes indicated grading 15.78 grams per tonne gold and 71.27 grams per tonne silver in the Boulder and Boulder East veins with an additional 460 028 tonnes inferred grading 10.09 grams per tonne gold and 45.61 grams per tonne silver in the Boulder, Boulder East, Argillite and Boulder HW veins using a 3.42 gram per tonne gold and 23.94 grams per tonne silver cut-off grade (Blue Lagoon Resources Inc. [2020-07-13]: Preliminary Economic Assessment, Dome Mountain Mine, British Columbia, Canada).
In December 2020, Blue Lagoon Resources Inc. reported an updated undiluted mineral resource of 175 980 tonnes indicated grading 12.45 grams per tonne gold and 60.41 grams per tonne silver in the Boulder and Boulder East veins with an additional 408 105 tonnes inferred grading 8.32 grams per tonne gold and 36.12 grams per tonne silver in the Boulder, Boulder East, Argillite and Boulder HW veins using a 2.25-metre minimum mining width and 3.42 gram per tonne gold and 23.94 grams per tonne silver cut-off grade (Blue Lagoon Resources Inc. [2020-07-13]: NI 43-101 Technical Report, Dome Mountain Mine, British Columbia, Canada).