By Leia Michele Toovey- Exclusive to Copper Investing News
Canada is the third largest copper producer in the world, after Chile and the USA. In Canada, copper is always produced in conjunction with another metal, most often as a co-product with nickel, zinc, lead, gold and molybdenum. Copper, as well as most of the base metals mined in Canada are hosted in massive sulphide sources and porphyry deposits.
Copper is widespread in Canada, however, areas where the metal is concentrated enough to be mined profitably are limited. British Columbia is the largest copper-producing province, followed by Ontario. Large-scale copper mining began in Quebec, the third-largest producer, with the opening of the Horne mine at Noranda late in 1927. The smelter now recycles copper and produces primary copper. Copper production in Manitoba, Canada’s fourth largest copper-producing province, is centered on the copper smelter in Flin Flon. Elsewhere in Canada, copper is recovered only in minor amounts.
The most common copper deposits in Canada are accumulations of massive sulphides from volcanic or magmatic activity, and porphyries, which have a magmatic origin. Copper occurs in many forms, but the circumstances that control how, when, and where it is deposited are highly variable. As a result, copper occurs in many different minerals. Copper deposits are broadly classified on the basis of how the deposits formed. Porphyry copper deposits, which are associated with igneous intrusions, yield about two-thirds of the world’s copper and are therefore the world’s most important type of copper deposit. The major products from porphyry copper deposits are copper and molybdenum, or copper and gold. Sulphide deposits normally contain higher grades of copper and its co-products, and are also generally larger overall deposits.
The term porphyry copper now includes engineering as well as geological considerations; it refers to large, relatively low grade, epigenetic, intrusion-related deposits that are extracted via open-pit mining. Geologically, the deposits occur close to or in granitic intrusive rocks that are porphyritic in texture. There are usually several episodes of intrusive activity, therefore, secondary mineralization is common. Porphyry deposits occur in two main settings within the orogenic belts; in island arcs and at continental margins.
The massive porphyry deposit that runs as a belt up and down British Columbia is a result of the orogeny created through the crustal stresses arising from the Pacific and North American plate convergence. Mineralization in porphyry deposits is mostly on fractures or in alteration zones adjacent to fractures. Porphyry-type mineral deposits result when large amounts of hot water that carry small amounts of metals pass through permeable rocks and deposit the metals. Original sulphide minerals in these deposits are pyrite, chalcopyrite, bornite and molybdenite. When it comes to copper, chalcopyrite is considered the most important ore.
Highland Valley Copper Mine
The Highland Valley Copper Mine, located in British Columbia, is the largest copper mine in Canada and one of the largest copper mining and concentrating operations in the world. It is owned (97.5 %) and operated by Teck Resources Limited (NYSE:TCK). The mining operation has yielded more than 2.8Mt of copper in concentrate during its lifetime. Copper production in 2008 totaled 119,300t and molybdenum production totaled 4.2 million pounds. Highland Valley is a low-grade (0.4per Cu) porphyry copper-molybdenum deposit.
The Highland Valley Copper was created as a partnership between Rio Algom and Cominco in 1986 to combine the Bethlehem and Lornex mines. Following the merger between Teck and Cominco in 2001, the 2000 takeover of Rio Algom by Billiton and Billiton’s subsequent merger with BHP, the mine was then majority owned by Teck Cominco (63.9%) and BHP Billiton (33.6%). At the beginning of 2004, Teck Cominco exercised its pre-emptive rights over BHP Billiton’s holding when the latter put it up for sale, hence Teck is now the majority owner. Production at the mine has decreased significantly the last few years due to an increased reliance on the lower-grade Lornex pit in line with a $300 million CDN mine expansion project designed to push its life expectancy out to 2019.
The rest of British Columbia is under-explored. There is a belt that runs up the majority of the province, believed to be tied closely with the famous Highland Valley Deposit. The reason that this belt remains under-explored is because a lot of the ore is capped, either by glacial drift or thin basalt. In the past, this provided a hindrance to exploration, but given the magnitude of the Highland Valley Deposit, extracting copper from the province even though it may be buried is worth the risk. Additionally,because this copper belt is associated with deposits of molybdenum and gold, exploration is heating up in the area. An example of juniors currently active in the area are Fjordland Explorations (CVE: FEX), and Bell Copper (CVE: BCU).
In Ontario, copper was mined in addition to the more famous metal in the area—nickel. Quadra FNX (TSE: QUX) is still actively exploring in the region. The Sudbury Basin, also known as Sudbury Structure or the Sudbury Nickel Irruptive, is a major geologic structure in Ontario. It is the second-largest known impact crater on Earth, as well as one of the oldest. The large impact crater was filled with magma containing nickel, copper, platinum, palladium, gold and other metals.
In addition to the impact crater, five other events contributed to the geology of the region. These include, order in age from oldest to youngest, the Penokean orogeny, formation of the Sudbury Igneous Complex, the Mazatzal orogeny, the Grenville orogeny, and the Lake Wanapitei impact. In Sudbury, the development of a mining settlement occurred in 1883 after blasting connected to the railway construction revealed a large concentration of nickel and copper ore at the Murray Mine site. As a result of these metal deposits, the Sudbury area is one of the world’s major mining communities. The region is one of the world’s largest suppliers of nickel and copper ores.
The Flin Flon area of Manitoba is another example of a historic producer with future potential. The Flin Flon deposits are a result of submarine volcanoes that erupted between 1920 and 1880 million years ago. These volcanoes formed near a convergent plate boundary, which caused a great deal of metamorphism, and copper deposition.