Faults and Fissures Vein Deposits
The discovery of silver and gold vein deposits marked the start of Canada’s mining legacy. The discovery of gold at Kirkland Lake and Timmins and silver in Cobalt and near Thunder Bay set the stage for the development of these parts of Canada’s hinterland and founded the development of a mining culture that continues today. …
Gold mining has come a long way in Ontario since the first property, the Richardson Mine in Eldorado near Madoc, fizzled shortly after its 1867 opening. The scattering of small mines working in northwestern Ontario eked out a few ounces of gold in the early part of the twentieth century. The success of the Cobalt camp gave witness to the Mexican proverb, “It takes a silver mine to make a gold mine,” by providing a labour pool and ready financing for the rich gold bonanzas of the Porcupine and Kirkland Lake.
The Porcupine-Timmins area produced 67 million ounces of gold from 48 mines between 1910 and 2004. The smaller but richer grade Kirkland Lake camp had an output from twenty-four mines that gave up 42 million ounces between 1917 and 1990.
The Kirkland Lake and Timmins camps are in close proximity to each other and are both within the Abitibi, the largest greenstone belt in the world. The major producers in these camps are or were in Kirkland Lake: the Toburn, the Wright Hargreaves, Lake Shore, Teck Hughes Kirkland Lake Gold and Macassa. Farther east are the Dobie-area Upper Canada Mine and the great Kerr Addison Mine at Virginiatown, close by the Quebec border.
The Timmins-Porcupine camp is much larger in land area and has had among the larger properties: the Aunor, Coniarum, Dome, Pamour, Hollinger, Hoyle Pond, McIntyre, Owl Creek, Paymaster and Preston.
There is a mixture of mineral deposit types along the two camps and they have been placed together for convenience. All are confined to the Porcupine-Dector Fault structure and its splays or subsidiaries.
Three gold mines are operated in Timmins as a joint venture, the principal owners banding together to avoid duplication of resources and to obtain economies of scale. The Dome Mine was founded in 1910 and is the oldest in the camp. The largest and second largest mines in the Timmins camp commenced production shortly after the Dome went into operation. However, the Hollinger and MacIntyre, adjacent to each other and with connecting underground mine workings,
ran out of economic ore in the early sixties.
The Pamour Mine, in which famed mining pioneer Viola MacMillan had an early interest, commenced operations in 1935, one of many properties which came into being when President Roosevelt increased and stabilized the price of gold at $35 (U.S.) an ounce.
Hoyle Pond was originally a project of Texas Gulf and began operating in 1982. The Dome is located on the outskirts of South Porcupine; Hoyle Pond is five kilometers north of Highway 101, the main road to Timmins; and Pamour is two kilometres south of the Hoyle property. Visitors cannot miss the giant pit as it is right on the highway. The Pamour head-frame is gone now, and Highway 101 has been rerouted once to permit more mining. A new direction for the main route to the city has been carved out again to facilitate joint venture mining.
The Dome geology offers veins and disseminated sulphides. Pamour is a vein structure and at Hoyle the gold is either native or in a pyrite mix. In 2006 the partners shared 374,921 ounces at an unspecified grade.
The Macassa Mine commenced producing gold in 1932. The last mine on the three miles of gold of the Kirkland Lake camp is almost at the centre of the famed Abitibi greenstone mineral belt. The ore in the camp tends to trend progressively deeper from east to west, and pioneer prospector Harry Oakes (later Sir Harry) was one of those who suggested that gold would only be found at depth.
After a succession of owners, the Macassa Mine is now controlled by Kirkland Lake Gold
Ltd. which also has the ground of four other former mines including Lake Shore which made the Oakes fortune, and the Wright Hargreaves, whose proceeds enabled Bill Wright to found the Globe and Mail newspaper.
Located off Highway 11, 240 kilometres north of North Bay, Macassa in its time has had annual production of more than 100,000 ounces but the property was closed due to rock bursts and shaft damage in 1999. The present owner instituted an aggressive exploration effort and in 2005 45,865 ounces at a 0.335 grade were recovered. Reserves had been raised to 927,000 ounces by the close of 2005, and it was expected that output would be closer to 90,000 ounces in 2006.
The Macassa story is happier, with exploration potential at depth excellent, compared to the giant Kerr Addison Mine at Virginiatown, close by the Quebec border, which has unknown remaining exploration potential.
Once the largest gold mine in the country, it mined 10,457.441 ounces at a fi ne 0.259 ounce grade before it was closed after six decades of service following a take-over by a junior that eventually went bankrupt.
A string of small mines have operated east of Matheson on Highway 101. The area has always attracted interest from mining buffs because of the Croesus Mine which operated intermittently from 1915 to 1936 at a handsome 2.8 ounces to the tonne grade giving up 14,859 ounces, mostly in the area of the shaft. The largest producer was the Holt-McDermott mine which operated from 1988 to 2004 with 1,322,332 ounces at a 0.162 ounce grade. This mine was associated with well-known miner Dit Holt.
Across the road another Noranda Exploration success, Holloway Mine, was also started up in 1988 and is now owned by Newmont, annually delivering 75,488 ounces at 6.0 grams to the tonne. The company has acquired the ground of its neighbour, the Holt McDermott.
Michael Barnes is a published Canadian author who has written extensively on Northern Ontario. [email protected]
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