RARE officiel Brochure Orig - Région Or du Canada 1866 - Logan/Michel/Chasse Ottawa

Life

William Edmond Logan was born into a well-to-do Montreal family in 1798, the third son of William Logan, a baker and owner of real estate, and Janet Edmond, both originally from Scotland.

Logan was sent to Edinburgh to receive an education. As was common at the time for young men of means, he learned languages (French, Spanish, some Gaelic and German), music (flute), and became an accomplished artist. In the 1830s, Logan became fascinated with geology while managing a copper-smelting works near Swansea, Wales, on behalf of his uncle, Hart Logan. His self-taught talent for the subject soon brought his geological maps and interpretations to the attention of the most eminent geologists of Great Britain, and it was their later recommendations that clinched Logans appointment as the founding director of the Geological Survey of Canada (GSC).

The need for an organization that could chart the mineral resources of the newly established Province of Canada (following the merger of Upper and Lower Canada) had been under discussion for over a decade. Government funds were allocated in 1841 and Logan took up his duties in 1842.

By the spring of 1843, Logan had established the Surveys headquarters in what he described as a "small and dark room" in Montreal. He had also hired Scottish-born Alexander Murray, a former naval officer, as his assistant. The rapid industrial advances in England since the late 18th century had shown how essential coal was to economic expansion. With the accepted belief that North Americas destiny lay in applying industrial technology to rich natural resources, the search for coal became the Surveys first priority.

The 1843 field season saw Logan working between Pictou, Nova Scotia, and the Gaspé, as well as Murray between Lake Erie and Lake Huron. The following year, Logan mapped the north shore of the Gaspé Peninsula and then explored inland to the mountains along the Cap Chat River. Logans assistants named the highest peak in his honour (this Mount Logan is not to be confused with Canadas highest mountain, which is located in Yukon and also named for him).

Based on information gathered during the first two field seasons, Logan was able to report that no coal deposits were to be found in the Province of Canada. Logans conclusion undoubtedly made the idea of amalgamating with the coal-rich Maritime Provinces attractive, and was one of the factors leading to Confederation in 1867.

Logan also made many important discoveries in the early days of the Survey. For example, he identified several broad geological divisions: folded rocks covering Quebecs Gaspé Peninsula and Eastern Townships; the nearly flat-lying limestones that extend west from Montreal to Lake Huron; and much older crystalline rocks extending north an unknown distance from Kingston, Ottawa, and Montreal. The latter soon proved to be the southernmost exposed section of Canadas mineral-rich Precambrian Shield.

In addition to Logans skills at geological observation and surviving in the wilds, he was an adept manager; during the 1850s he built up the staff of the GSC, adding a paleontologist, a chemist, more geologists, and a museum technician, amongst others. He also lobbied the government successfully for continued funding for the GSC, although he would use his own funds when necessary; he was an independently wealthy man, and to the despair of many parents hoping to snag him as a son-in-law, his response was always that he was "married to the rocks." By the late 1850s, Logan had built the GSC into a well-rounded organization capable of conducting rigorous exploration, making maps, analyzing and identifying mineral and fossil specimens, producing reports, and maintaining a public museum.

The 1850s saw the beginning of the great international expositions, and Logan was a talented promoter of Canadas mineral resources abroad, starting with the Exhibition of the Industry of All Nations, the 1851 world fair at the Crystal Palace in London, England. A second similar opportunity came in 1855 with the Universal Exposition in Paris. Canadas participation in these high-profile events stimulated international interest in Canadian minerals and brought personal honours to Logan. He received the French Cross of the Legion of Honour from Napoleon III in 1855, and his greatest honour, his knighthood bestowed by Queen Victoria at Windsor Castle in 1856. That same year he was awarded the Wollaston Medal, the highest award of the Geological Society of London. Throughout his career, Logan was to receive dozens of prestigious awards.

Logan was also an influential museum builder. In 1856, he was authorized by the government to establish a Geological Museum open to the public – which he did at the GSC headquarters in Montreal. This museum was to grow through the years, and both the Canadian Museum of Nature and the Canadian Museum of History trace their roots to it.

One of the most important accomplishments of the GSC under Logan was the publication in 1863 of the Geology of Canada. Representing all the work of the organization up to that date, this 983-page book recorded everything known about Canadian geology. It received national and international acclaim for its content, style, and precision.

In 1869, Logans geological map of Canada was published (the map is actually dated 1866). On a scale of 1 inch to 25 miles, it showed the geology and geography of southeastern Canada as far west as Manitoba and as far north as lakes St. John, Timiskaming, Nipigon, and St. Joseph. In 1864, a smaller scale version of this same map (1 inch to 125 miles) had been printed in atlas form, making it the first comprehensive illustration of the geology of what is now the southern part of Ontario and Quebec.

Logan retired in 1869 at the age of 71. He died at Castle Malgwyn in Wales, the home of his sister, Elizabeth Gower, on 22 June 1875, and is buried in the churchyard of St Llawddog at Cilgerran, Pembrokeshire, Wales.

Sir William Edmond Logan (1869)

Born20 April 1798

Montreal, Lower Canada

Died22 June 1875 (aged 77)

Castell Malgwyn, Wales

NationalityCanadian

Alma materUniversity of Edinburgh

Known for"Geology of Canada" (1863)

AwardsWollaston Medal (1856)

Royal Medal (1867)

Scientific career

FieldsGeology

InstitutionsDirector of the Geological Survey of Canada (1842-69)

The Geological Survey of Canada (GSC; French: Commission géologique du Canada (CGC)) is a Canadian federal government agency responsible for performing geological surveys of the country, developing Canadas natural resources and protecting the environment. A branch of the Earth Sciences Sector of Natural Resources Canada, the GSC is the countrys oldest scientific agency and was one of its first government organizations.

In September 1841, the Province of Canada legislature passed a resolution that authorized the sum of £1,500 sterling be granted to the government for the estimated expense of performing a geological survey of the province. In 1842, the Geological Survey of Canada was formed to fulfill this request.[1]

The First Canadian Pacific R.R. and Geological Survey parties for British Columbia, July 22, 1871. Photographer: Benjamin F Baltzy. Courtesy: Toronto Public Library Digital Collections

Geological Survey of Canada building in Montreal, 1852–1874

Geological Survey of Canada building in Montreal, 1852–1874

William Edmond Logan was in Montreal at the time and made it known that he was interested in participating in this survey. Gaining recommendations from prominent British scientists, Logan was appointed the first GSC director on April 14, 1842. Four months later, Logan arrived in Kingston, Ontario, to compile the existing body of knowledge of Canadas geology. In the spring of 1843, Logan established the GSCs headquarters in Montreal (in his brothers warehouse and then in a rented house on Great St. James Street (now Saint Jacques Street).[2] One of the prominent cartographers and the chief topographical draughtsman was Robert Barlow, who began his work in 1855. Chemist T. Sterry Hunt joined in the early days and the Survey added paleontological capability in 1856 with the arrival of Elkanah Billings.[1] After Aylesworth Perry was appointed as acting librarian in 1881 he prepared the catalogue of reference works on geology, mineralogy, metallurgy, chemistry and natural history.[3] George Mercer Dawson became a staff member in 1875, progressed to assistant director in 1883 and finally to director of the Geological Survey of Canada in 1895.[1] The Geological Survey of Canada first began allowing women to conduct fieldwork in the early 1950s.[4] Dr. Alice Wilson, the first of these women, lobbied for the inclusion of paleontologist Frances Wagner shortly afterward.[4] Around this same time, the GSC employed a third woman Dr. Helen Belyea.[4]

Seismograph Network

The Canadian National Seismograph Network is monitored by the Geological Survey of Canada.

Geomagnetic monitoring

The Geological Survey Canada operates a network of 14 magnetic observatories throughout Canada, located as follows:[5][6]

Nunavut: Alert, Baker Lake, Cambridge Bay, Eureka, Iqaluit, Resolute Bay, Sanikiluaq

Northwest Territories: Yellowknife

British Columbia: Victoria

Alberta: Meanook

Manitoba: Brandon, Churchill

Ontario: Ottawa

Newfoundland and Labrador: St. Johns

See also

Geology of Canada

Former Geological Survey of Canada Building

Gold mining is the resource extraction of gold by mining.

History

A miner underground at Pumsaint gold mine Wales; c. 1938?.

Landscape of Las Médulas, Spain, the result of hydraulic mining on a vast scale by the Ancient Romans

Late 15th and early 16th century mining techniques, De re metallica

It is impossible to know the exact date that humans first began to mine gold, but some of the oldest known gold artifacts were found in the Varna Necropolis in Bulgaria. The graves of the necropolis were built between 4700 and 4200 BC, indicating that gold mining could be at least 7000 years old.[1] A group of German and Georgian archaeologists claims the Sakdrisi site in southern Georgia, dating to the 3rd or 4th millennium BC, may be the worlds oldest known gold mine.[2]

Bronze age gold objects are plentiful, especially in Ireland and Spain, and there are several well known possible sources. Romans used hydraulic mining methods, such as hushing and ground sluicing on a large scale to extract gold from extensive alluvial (loose sediment) deposits, such as those at Las Medulas. Mining was under the control of the state but the mines may have been leased to civilian contractors some time later. The gold served as the primary medium of exchange within the empire, and was an important motive in the Roman invasion of Britain by Claudius in the first century AD, although there is only one known Roman gold mine at Dolaucothi in west Wales. Gold was a prime motivation for the campaign in Dacia when the Romans invaded Transylvania in what is now modern Romania in the second century AD. The legions were led by the emperor Trajan, and their exploits are shown on Trajans Column in Rome and the several reproductions of the column elsewhere (such as the Victoria and Albert Museum in London).[3] Under the Eastern Roman Empire Emperor Justinians rule, gold was mined in the Balkans, Anatolia, Armenia, Egypt, and Nubia.[4]

In the area of the Kolar Gold Fields in Bangarpet Taluk, Kolar District of Karnataka state, India, gold was first mined prior to the 2nd and 3rd century AD by digging small pits. (Golden objects found in Harappa and Mohenjo-daro have been traced to Kolar through the analysis of impurities — the impurities include 11% silver concentration, found only in KGF ore.[citation needed]) The Champion reef at the Kolar gold fields was mined to a depth of 50 metres (160 ft) during the Gupta period in the fifth century AD. During the Chola period in the 9th and 10th century AD, the scale of the operation grew.[citation needed] The metal continued to be mined by the eleventh century kings of South India, the Vijayanagara Empire from 1336 to 1560, and later by Tipu Sultan, the king of Mysore state and the British. It is estimated that the total gold production in Karnataka to date is 1000 tons.[5]

The mining of the Hungarian deposit (present-day Slovakia) primarily around Kremnica was the largest of the Medieval period in Europe.[6]

During the 19th century, numerous gold rushes in remote regions around the globe caused large migrations of miners, such as the California Gold Rush of 1849, the Victorian Gold Rush, and the Klondike Gold Rush. The discovery of gold in the Witwatersrand led to the Second Boer War and ultimately the founding of South Africa.

The Carlin Trend of Nevada, U.S., was discovered in 1961. Official estimates indicate that total world gold production since the beginning of civilization has been around 6,109,928,000 troy ounces (190,040.0 t) and total gold production in Nevada is 2.5% of that, ranking Nevada as one of the Earths primary gold producing regions.[7][8]

As of 2017, the worlds largest gold producer by far was China with 429.4 tonnes in that year. The second-largest producer, Australia, mined 289.0 tonnes in the same year, followed by Russia with 273 tonnes.[9]

Statistics

Despite the decreasing gold content of ores, the production is increasing. This can be achieved with industrial installations, and new process, like hydrometallurgy.

Trends in some gold-producing countries

Annual world mined gold production, 1900-2014

Gold ore grade evolution

Methods

Placer mining

Main article: Placer mining

Gold in a pan—Alaska

Placer mining is the technique by which gold that has accumulated in a placer deposit is extracted. Placer deposits are composed of relatively loose material that makes tunneling difficult, and so most means of extracting it involve the use of water or dredging.

Panning

Main article: Gold panning

Gold panning is mostly a manual technique of separating gold from other materials. Wide, shallow pans are filled with sand and gravel that may contain gold. The pan is submerged in water and shaken, sorting the gold from the gravel and other material. As gold is much denser than rock, it quickly settles to the bottom of the pan. The panning material is usually removed from stream beds, often at the inside turn in the stream, or from the bedrock shelf of the stream, where the density of gold allows it to concentrate, a type called placer deposits.

Gold panning is the easiest and quickest technique for searching for gold, but is not commercially viable for extracting gold from large deposits, except where labor costs are very low or gold traces are substantial. Panning is often marketed as a tourist attraction on former gold fields. Before large production methods are used, a new source must be identified and panning is useful to identify placer gold deposits to be evaluated for commercial viability.

Sluicing

Gold sluicing at Dilban Town, New Zealand, 1880s

Taking gold out of a sluice box, western North America, 1900s

Using a sluice box to extract gold from placer deposits has long been a very common practice in prospecting and small-scale mining. A sluice box is essentially a man made channel with riffles set in the bottom. The riffles are designed to create dead zones in the current to allow gold to drop out of suspension. The box is placed in the stream to channel water flow. Gold-bearing material is placed at the top of the box. The material is carried by the current through the volt where gold and other dense material settles out behind the riffles. Less dense material flows out of the box as tailings.

Larger commercial placer mining operations employ screening plants, or trommels, to remove the larger alluvial materials such as boulders and gravel, before concentrating the remainder in a sluice box or jig plant. These operations typically include diesel powered, earth moving equipment, including excavators, bulldozers, wheel loaders, and rock trucks.

Dredging

Main article: Gold dredge

Although this method has largely been replaced by modern methods, some dredging is done by small-scale miners using suction dredges. These are small machines that float on the water and are usually operated by one or two people. A suction dredge consists of a sluice box supported by pontoons, attached to a suction hose which is controlled by a miner working beneath the water.

State dredging permits in many of the United States gold dredging areas specify a seasonal time period and area closures to avoid conflicts between dredgers and the spawning time of fish populations. Some states, such as Montana, require an extensive permitting procedure, including permits from the U.S. Corps of Engineers, the Montana Department of Environmental Quality, and the local county water quality boards.

Some large suction dredges (100 horsepower (75 kW) & 250 mm (10 in)) are used in commercial production throughout the world. Small suction dredges are much more efficient at extracting smaller gold than the old bucket line. This has improved the chances of finding gold. Smaller dredges with 50-to-100-millimetre (2 to 4 in) suction tubes are used to sample areas behind boulders and along potential pay streaks, until "colour" (gold) appears.

Other larger scale dredging operations take place on exposed river gravel bars at seasonal low water. These operations typically use a land based excavator to feed a gravel screening plant and sluice box floating in a temporary pond. The pond is excavated in the gravel bar and filled from the natural water table. "Pay" gravel is excavated from the front face of the pond and processed through the floating plant, with the gold trapped in the onboard sluice box and tailings stacked behind the plant, steadily filling in the back of the pond as the operation moves forward. This type of gold mining is characterized by its low cost, as each rock is moved only once. It also has low environmental impact, as no stripping of vegetation or overburden is necessary, and all process water is fully recycled. Such operations are typical on New Zealands South Island and in the Klondike region of Canada.

Rocker box

Also called a cradle, it uses riffles located in a high-walled box to trap gold in a similar manner to the sluice box. A rocker box uses less water than a sluice box and is well suited for areas where water is limited. A rocking motion provides the water movement needed for the gravity separation of gold in placer material.

Hard rock mining

Hard rock mining at the Associated Gold Mine, Kalgoorlie, Australia, 1951

Gold mining in Coromandel Peninsula, New Zealand, in the 1890s

Main articles: Quartz reef mining and Carlin-type gold deposit

Hard rock gold mining extracts gold encased in rock, rather than fragments in loose sediment, and produces most of the worlds gold. Sometimes open-pit mining is used, such as at the Fort Knox Mine in central Alaska. Barrick Gold Corporation has one of the largest open-pit gold mines in North America located on its Goldstrike mine property in north eastern Nevada. Other gold mines use underground mining, where the ore is extracted through tunnels or shafts. South Africa has the worlds deepest hard rock gold mine up to 3,900 metres (12,800 ft) underground. At such depths, the heat is unbearable for humans, and air conditioning is required for the safety of the workers. The first such mine to receive air conditioning was Robinson Deep, at that time the deepest mine in the world for any mineral.[10]

By-product gold mining

Gold is also produced by mining in which it is not the principal product. Large copper mines, such as the Bingham Canyon mine in Utah, often recover considerable amounts of gold and other metals along with copper. Some sand and gravel pits, such as those around Denver, Colorado, may recover small amounts of gold in their wash operations. The largest producing gold mine in the world, the Grasberg mine in Papua, Indonesia, is primarily a copper mine.[11]

A modest amount of precious metal is a by-product of sodium production.

Gold ore processing

Main articles: Gold extraction and Gold parting

In placer mines, the gold is recovered by gravity separation. For hard rock mining, other methods are usually used.[12]

Cyanide process

Main article: Gold cyanidation

Cyanide extraction of gold may be used in areas where fine gold-bearing rocks are found. Sodium cyanide solution is mixed with finely ground rock that is proven to contain gold or silver, and is then separated from the ground rock as gold cyanide or silver cyanide solution. Zinc is added to precipitate out residual zinc as well as the silver and gold metals. The zinc is removed with sulfuric acid, leaving a silver or gold sludge that is generally smelted into an ingot then shipped to a metals refinery for final processing into 99.9999% pure metals.

Advancements in the 1970s have seen activated carbon used in extracting gold from the leach solution. The gold is absorbed into the porous matrix of the carbon. Activated carbon has so much internal surface area,[13] that fifteen grams of it has the equivalent surface area of the Melbourne Cricket Ground (18,100 square metres (195,000 sq ft)). The gold can be removed from the carbon by using a strong solution of caustic soda and cyanide, a process known as elution. Gold is then plated out onto steel wool through electrowinning. Gold specific resins can also be used in place of activated carbon, or where selective separation of gold from copper or other dissolved metals is required.

The technique using dissolution with alkaline cyanide has been highly developed over recent years. It is particularly appropriate for low grade gold and silver ore processing (e.g. less than 5 ppm gold) but its use is not restricted to such ores. There are many environmental hazards associated with this extraction method, largely due to the high acute toxicity of the cyanide compounds involved. A major example of this hazard was demonstrated in the 2000 Baia Mare cyanide spill, when a break in holding pond dam at a mine waste reprocessing facility near Baia Mare in northern Romania released approximately 100,000 cubic metres (3,500,000 cu ft) of waste water contaminated with heavy metal sludge and up to 120 long tons (122 t) of cyanide into the Tisza River.[14] As a consequence, most countries now have strict regulations for cyanide in plant discharges, and plants today include a specific cyanide-destruction step before discharging their tailings to a storage facility.

Mercury process

Historically, mercury was used extensively in placer gold mining in order to form mercury-gold amalgam with smaller gold particles, and thereby increase the gold recovery rates. Large-scale use of mercury stopped in the 1960s. However, mercury is still used in artisanal and small-scale gold mining (ASGM), often clandestine, gold prospecting.[15] It is estimated that 45,000 metric tons of mercury used in California for placer mining have not been recovered.[citation needed]

Business

Small operations

Woman panning for gold in Guinea

Old bellows on abandoned gold mine in western New South Wales, Australia

While most of the gold is produced by major corporations, tens of thousands of people work independently in smaller, artisan operations, in some cases illegally. In Ghana, for instance, the galamseys are estimated to number 20,000 to 50,000.[16] In neighboring francophone countries, such workers are called orpailleurs. In Brazil, such workers are called garimpeiros.

The high risk of such ventures was seen in the collapse of an illegal mine at Dompoase, Ashanti Region, Ghana, on 12 November 2009, when 18 workers were killed, including 13 women. Many women work at such mines as porters. It was the worst mining disaster in Ghanaian history.[16]

In order to maximize gold extraction, mercury is often used to amalgamate with the metal. The gold is produced by boiling away the mercury from the amalgam. Mercury is effective in extracting very small gold particles, but the process is hazardous due to the toxicity of mercury vapour.

Especially after the Minamata Convention has been ratified, there are initiatives to replace or reduce the use and emissions of mercury in the extraction of gold.[17]

Large companies

Main article: Largest gold companies

Barrick Gold, Goldcorp, Newmont Mining Corporation, Newcrest Mining, and AngloGold Ashanti are the worlds five largest gold mining companies by market capitalisation in 2008.

Adverse effects

Gold mining can significantly alter the natural environment. For example, gold mining activities in tropical forests are increasingly causing deforestation along rivers and in remote areas rich in biodiversity.[18][19] Other gold mining impacts, particularly in aquatic systems with residual cyanide or mercury (used in the recovery of gold from ore), can be highly toxic to people and wildlife even at relatively low concentrations.[20]

However, there are clear moves by many in the non-governmental organization community to encourage more environmentally friendly and sustainable business practices in the mining industry. The primary way this is being achieved is via the promotion of so-called clean or ethical gold. The aim is to get all end users/retailers of gold to adhere to set of principles that encourage sustainable mining. Campaigns such as No Dirty Gold[21] are driving the message that the mining industry is harmful (for the reasons noted above), and so must be cleaned up. Also, NGOs are urging the industry and consumers to buy sustainably produced gold. Human Rights Watch produced a report[22] that outlines some of challenges faced globally, noting that: "Thousands of children in the Philippines risk their lives every day mining gold. Children work in unstable 25-meter-deep pits that could collapse at any moment. They mine gold underwater, along the shore, or in rivers, with oxygen tubes in their mouths. They also process gold with mercury, a toxic metal, risking irreversible health damage from mercury poisoning." Along with many other reports and articles, this has had the effect of spurring retailers and industry bodies to move toward sustainable gold. Indeed, the World Jewellery Confederation insists that it does all it can to "Deliver a Sustainable and Responsible Jewellery Industry."[1] Likewise, the use of so-called Fairtrade gold is growing; with businesses moving over to, or at least offering, this option at both retail and wholesale levels.

See also: Gold § Pollution, and List of gold mining disasters

Safety

Noise

Within the United States, the Mine Safety and Health Administration (MSHA) has set noise exposure limits for those within the mining industry. These noise exposure guidelines state that the "Permissible Exposure Level" (PEL) of noise is 90 dBA as an 8-hour time-weighted-average.[23] Mine workers exposed to a time-weighted average of at least 85 dBA fall into the "Action Level" in which workers with exposures exceeding that level are placed into a hearing conservation program. The National Institute for Occupational Safety and Health (NIOSH) has examined noise exposures of gold mine workers. One study found that gold mine workers noise exposures ranged from 165-261% of the MSHA PEL.[24] Haul truck operators, load-haul-dump operators, single boom drill operators, and roof bolter operators represented the occupations with the highest noise exposures within gold mines.[24]

See also

Sibanye Gold

Gold extraction

Gold rush

Gold prospecting

Ore genesis

Peak gold

Quartz reef mining

Recreational gold mining

List of gold nuggets by size

Gold mining by country:

Witwatersrand around Johannesburg, South Africa

Witwatersrand Basin in South Africa

Deepest mines on earth are the gold mines in South Africa

Gold mining in Africa

Gold mining in South Africa

Gold mining in Australia

Gold mining in the United States

Gold mining in Alaska

City of Gold in Canada

Gold mining in China

Gold mining in India

Hatti Gold Mines

Kolar Gold Fields

Gold mining in Guyana

Aurora gold mine

Omai mine

Toroparu mine

Gold mining in Pakistan:

Reko Diq Mine

Saindak Copper Gold Project

Welsh gold

Sukari, Egypt

Gold rushes:

United States:

Georgia Gold Rush (beginning 1828)

California Gold Rush (1848–1855)

Pikes Peak Gold Rush (1858–1860)

Holcomb Valley gold rush (1860s)

British Commonwealth:

Australian gold rushes (1850s)

Victorian Gold Rush (1851–1860s)

Fraser Canyon Gold Rush (late 1850s), Canada

Witwatersrand Gold Rush (1880s), South Africa

Klondike Gold Rush (1896–1899), Canada

Central Otago Gold Rush (1860s), New Zealand