back to Mining in Ontario

Mining is an important industry in Ontario, employing over 100,000 people, directly and indirectly, and producing about $10-billion worth of minerals annually. Ontario is Canada’s leader in metals mining, producing 53 per cent of the country’s gold, 47 per cent of its nickel and 31 per cent of its copper. Ontario is the second largest producer of nickel in the world.

Although metals are the most talked about mining products, other materials are just as important. Gravel is mined for use in building materials, such as concrete, and in roads and railways. Limestone is mined to be used in cement manufacture. Salt is mined for use on roads in winter and as a seasoning for food. Building stone is quarried in Ontario and has been used in such notable structures as the parliament buildings in Ottawa and the Canadian Embassy in Washington D.C..

Alberta is usually thought of as the oil province, yet $52-million worth of crude oil was produced in Ontario in 2007. In fact, the first oil well in North America was at Oil Springs (near Sarnia, in Southwestern Ontario) in 1858. Another product not often associated with Ontario is diamonds. The Victor Diamond Mine, located 90 kilometres west of James Bay in far northern Ontario, opened in 2008, with an annual production capacity of 600,000 carats of diamonds.

Sudbury is an important producer of nickel

map showing shape of sudbury structure and exposed rock units in the structure

A map of the Sudbury Structure.  Created by a meteorite impact 1.85 billion years ago, the originally-round feature was squeezed into an oval by geologic forces. From

Nickel is a vital industrial metal and Sudbury is one of the world’s most important nickel-producing areas. In 2006, Canada produced 11% (233,461 tonnes) of the world’s nickel, most of which came from the Sudbury area. That year, Canada tied with Japan for second place in world nickel production behind Russia, which produced 20% of the world’s nickel.

Nickel’s main use is in the manufacture of stainless steel, which consumes 60% of production. It is also used in other alloys, for electroplating, in coins and in batteries. Nickel is extensively recycled so that 45% to 48% of nickel used to make stainless steel comes from stainless steel scrap.

Although nickel has been part of useful alloys, such as bronze, for thousands of years, ancient metalsmiths probably had little understanding of nickel as a distinct substance. Nickel wasn’t “discovered” until 1751 when it was isolated by Swedish chemist Baron Axel Fredrik Cronstedt.

The presence of copper ore in the Sudbury area was noticed for the first time in 1856, however it wasn’t until 1887 that nickel was identified. Mining started soon after that and Inco (International Nickel) was formed.

It came from outer space

The Sudbury Structure, which hosts the nickel deposits that make the Sudbury area famous, is the result of a meteorite impact. Originally thought to be of volcanic origin, the oval Sudbury Structure (see map above) has been generally regarded as an impact site since the mid 1960s. The structure is 60 km long, 30 km wide and 10 km deep. It is thought to be a result of the impact of a meteorite, more than 4 km diameter, about 1.85 billion years ago. The original round impact structure was likely squeezed into its present oval shape by the geologic forces of plate tectonics (continental drift). At the time of formation, the crater may have been 250 km in diameter.

Evidence supporting a meteorite-impact origin for the Sudbury Structure includes an abundance of the element iridium, which is common in meteorites but rare in the Earth’s crust; rock types, such as the pseudotachylite Sudbury breccia and structures, such as shatter cones, typical of impact sites; and shock metamorphosed minerals, such as shocked quartz. The ore deposits which are exploited in the Sudbury area are probably a result of this impact. Although the origin of the ore minerals is still debated, their concentration in one area is likely due to the event which formed the Sudbury Structure.

Striking oil in Ontario

oil well tower with oil flowing from it

Oil gushing from a well near Petrolia. Photo from

The North American oil industry got its start in the towns of Oil Springs and Petrolia, near Sarnia in southwestern Ontario. In 1858, James Miller Williams was attempting to dig a water well, near an asphalt extraction well, when he struck oil, becoming the first person in North America to produce a commercial oil well. He later went on to set up Canada’s first refinery to produce kerosene from crude oil.

More oil was found in nearby Petrolia in 1866 and many oilmen left Oil Springs in favour of the new discovery. Both towns went through several booms and busts over the years, and oil is still produced in the area. A legacy of the Ontario oil boom were the oilmen who learned their craft in Petrolia and Oil Springs and took their skills to other oilfields around the world.

Salt of the Earth from Ontario

cardboard box with windsor salt logo on it.

The familiar Windsor Salt box.

Vital for seasoning food, clearing ice from roads and water softening, salt is abundant underground in Ontario, and is mined in Goderich and Windsor, in southwestern Ontario.

The Goderich salt mine is the largest salt mine in the world, extending five kilometres under Lake Huron and using heavy equipment in huge underground galleries to extract the salt. Operated by Sifto Canada, the mine exploits a deposit evaporated from a tropical sea, which covered the area during Silurian times, over 400 million years ago.

The salt was discovered 300 metres beneath Goderich harbour in 1866 by a team drilling for oil. It was the first salt deposit discovered in North America.

Ontario gold mining

5 hands belonging to 3 people holding giant gold coin

A 100-kilogram Canadian Gold Maple Leaf with a face value of $1-million. The world’s largest gold coin, it is half a metre in diameter and 25 millimetres thick. Five were produced by the Royal Canadian Mint in 2007 and one sold for $4-million in 2010. Photo from

Gold is the emperor of metals and gold mining has been an important factor in Ontario’s economy for many years. The yellow metal was first discovered in Ontario in 1866 in what is now Madoc Township, in central Ontario, about 50 kilometres north of Belleville. It was discovered accidentally by Marcus Powell, who was prospecting for copper when his pick broke into a cave which contained gold leaves and nuggets, the largest of which was reported to be about two by four centimetres.

Apparently, Powell didn’t believe he had struck gold and continued to hunt for copper for another month, when another gold deposit was found and a geologist confirmed the presence of gold. After that word began to spread, resulting in a gold rush, which lead to a building boom, land speculation and the founding of the boom town called Eldorado.

The gold rush was short-lived, however. The original find turned out to be an unusually-rich deposit, with most of the area containing relatively little gold. Technical and business problems also drove many mining companies out of business, so that by 1869 the gold rush was over. Interest in gold and exploration continued in the Eldorado area, and mining activity in nearby regions persisted into the 1940s, but gold fever had subsided and never overheated again.

It was a different story in the Porcupine region of northern Ontario, near the modern city of Timmins, where gold mining continues to this day. There were reports of gold in the area in the late 19th century, but it wasn’t until transportation to the region was improved by new railways that extensive prospecting was possible. The discoveries which lead to the Porcupine Gold Rush were made in 1909. A total of 2,083,901 kilograms of gold had been extracted from the area by 2001, making the Porcupine one of the biggest gold rushes in history. In comparison, the Klondike Gold Rush produced 373,236 kilograms of gold.