In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation; the hydraulic flow involved is due to hydrothermal circulation. Veins are classically thought of as being the result of growth of crystals on the walls of planar fractures in rocks, with the crystal growth occurring normal to the walls of the cavity, the crystal protruding into open space; this is the method for the formation of some veins. However, it is rare in geology for significant open space to remain open in large volumes of rock several kilometers below the surface. Thus, there are two main mechanisms considered for the formation of veins: open-space filling and crack-seal growth. Open space filling is the hallmark of epithermal vein systems, such as a stockwork, in greisens or in certain skarn environments. For open space filling to take effect, the confining pressure is considered to be below 0.5 GPa, or less than 3–5 km.
Veins formed in this way may exhibit a colloform, agate-like habit, of sequential selvages of minerals which radiate out from nucleation points on the vein walls and appear to fill up the available open space. Evidence of fluid boiling is present. Vugs and geodes are all examples of open-space filling phenomena in hydrothermal systems. Alternatively, hydraulic fracturing may create a breccia, filled with vein material; such breccia vein systems may be quite extensive, can form the shape of tabular dipping sheets, diatremes or laterally extensive mantos controlled by boundaries such as thrust faults, competent sedimentary layers, or cap rocks. When the confining pressure is too great, or when brittle-ductile rheological conditions predominate, vein formation occurs via crack-seal mechanisms. Crack-seal veins are thought to form quite during deformation by precipitation of minerals within incipient fractures; this happens swiftly by geologic standards, because pressures and deformation mean that large open spaces cannot be maintained.
Veins grow in thickness by reopening of the vein fracture and progressive deposition of minerals on the growth surface. Veins need either hydraulic pressure in excess of hydrostatic pressure or they need open spaces or fractures, which requires a plane of extension within the rock mass. In all cases except brecciation, therefore, a vein measures the plane of extension within the rock mass, give or take a sizeable bit of error. Measurement of enough veins will statistically form a plane of principal extension. In ductilely deforming compressional regimes, this can in turn give information on the stresses active at the time of vein formation. In extensionally deforming regimes, the veins occur normal to the axis of extension. Veins are of prime importance to mineral deposits, because they are the source of mineralisation either in or proximal to the veins. Typical examples include gold lodes, as well as skarn mineralisation. Hydrofracture breccias are classic targets for ore exploration as there is plenty of fluid flow and open space to deposit ore minerals.
Ores related to hydrothermal mineralisation, which are associated with vein material, may be composed of vein material and/or the rock in which the vein is hosted. In many gold mines exploited during the gold rushes of the 19th century, vein material alone was sought as ore material. In most of today's mines, ore material is composed of the veins and some component of the wall rocks which surrounds the veins; the difference between 19th-century and 21st-century mining techniques and the type of ore sought is based on the grade of material being mined and the methods of mining which are used. Hand-mining of gold ores permitted the miners to pick out the lode quartz or reef quartz, allowing the highest-grade portions of the lodes to be worked, without dilution from the unmineralised wall rocks. Today's mining, which uses larger machinery and equipment, forces the miners to take low-grade waste rock in with the ore material, resulting in dilution of the grade. However, today's mining and assaying allows the delineation of lower-grade bulk tonnage mineralisation, within which the gold is invisible to the naked eye.
In these cases, veining is the subordinate host to mineralisation and may only be an indicator of the presence of metasomatism of the wall-rocks which contains the low-grade mineralisation. For this reason, veins within hydrothermal gold deposits are no longer the exclusive target of mining, in some cases gold mineralisation is restricted to the altered wall rocks within which barren quartz veins are hosted. Boudinage Ore genesis Shear
A stamp mill is a type of mill machine that crushes material by pounding rather than grinding, either for further processing or for extraction of metallic ores. Breaking material down is a type of unit operation. A stamp mill consists of a set of heavy steel stamps, loosely held vertically in a frame, in which the stamps can slide up and down, they are lifted by cams on a horizontal rotating shaft. As the cam moves from under the stamp, the stamp falls onto the ore below, crushing the rock, the lifting process is repeated at the next pass of the cam; each one frame and stamp set is sometimes called a "battery" or, confusingly, a "stamp" and mills are sometimes categorised by how many stamps they have, i.e. a "10 stamp mill" has 10 sets. They are arranged linearly, but when a mill is enlarged, a new line of them may be constructed rather than extending the line. Abandoned mill sites will have linear rows of foundation sets as their most prominent visible feature as the overall apparatus can exceed 20 feet in height, requiring large foundations.
Stamps are arranged in sets of five. Some ore processing applications used large quantities of water so some stamp mills are located near natural or artificial bodies of water. For example, the Redridge Steel Dam was built to supply stamp mills with process water; the main components for water-powered stamp mills – water wheels and hammers – were known in the Hellenistic era Eastern Mediterranean region. Ancient cams are in evidence in early water-powered automata from the third century BC. A passage in the Natural History of the Roman scholar Pliny indicates that water-driven pestles had become widespread in Italy by the first century AD: "The greater part of Italy uses an unshod pestle and wheels which water turns as it flows past, a trip-hammer "; these trip-hammers were used for the hulling of grain. Grain-pounders with pestles, as well as ordinary watermills, are attested as late as the middle of the fifth century in a monastery founded by Romanus of Condat in the remote Jura region, indicating that the knowledge of trip hammers continued into the early Middle Ages.
Apart from agricultural processing, archaeological evidence strongly suggests the existence of trip hammers in Roman metal working. In Ickham in Kent, a large metal hammer-head with mechanical deformations was excavated in an area where several Roman water-mills and metal waste dumps have been traced; the widest application of stamp mills, seems to have occurred in Roman mining, where ore from deep veins was first crushed into small pieces for further processing. Here, the regularity and spacing of large indentations on stone anvils indicate the use of cam-operated ore stamps, much like the devices of medieval mining; such mechanically deformed anvils have been found at numerous Roman silver and gold mining sites in Western Europe, including at Dolaucothi, on the Iberian peninsula, where the datable examples are from the 1st and 2nd century AD. At Dolaucothi, these stamp mills were hydraulic-driven and also at other Roman mining sites, where the large scale use of the hushing and ground sluicing technique meant that large amounts of water were directly available for powering the machines.
Stamp mills were used by miners in Samarkand as early as 973. They were used in medieval Persia to crush mineral ores. By the 11th century, stamp mills were in widespread use throughout the medieval Islamic world, from Islamic Spain and North Africa in the west to Central Asia in the east. Water-powered and mechanised trip hammers reappeared in medieval Europe by the 12th century, their use was described in medieval written sources of Styria, written in 1135 and another in 1175 AD. Both texts mentioned the use of vertical stamp mills for ore-crushing. Medieval French sources of the years 1116 and 1249 both record the use of mechanised trip hammers used in the forging of wrought iron. Medieval European trip hammers by the 15th century were most in the shape of the vertical pestle stamp-mill; the well-known Renaissance artist and inventor Leonardo da Vinci sketched trip hammers for use in forges and file-cutting machinery, those of the vertical pestle stamp-mill type. The oldest depicted European illustration of a martinet forge-hammer is the Historia de Gentibus Septentrionalibus of Olaus Magnus, dated to 1565 AD.
In this woodcut image, there is the scene of three martinets and a waterwheel working wood and leather bellows of an osmund bloomery furnace. The recumbent trip hammer was first depicted in European artwork in an illustration by Sandrart and Zonca. Water-powered stamp mills are illustrated in book 8 of Georg Agricola's De Re Metallica, published in 1556; the mills Agricola shows were wooden construction, excepting the use of iron shoes on the end of each stamp. The camshaft was set directly on the axle of the waterwheel, stamps were arranged in gangs of three, with each wheel driving one or two gangs; the first stamp mill in the U. S. was built in 1829 at the Capps mine near Charlotte, North Carolina. They were common in gold and copper mining regions of the US in the latter 19th and early 20th centuries, in operations where the ore was crushed as a prelude to extracting the metals, they were superseded in the second half of the 19th century in many applications by more efficient methods. However their simplicity meant that they were used in remote areas for ore processing well into the 20th century (19th century advertisements for some mills highlighted that they could be broken down, packed in by mule in pieces, assembled on site with only simpl
Mindat.org is a non-commercial online mineralogical database, claiming to be the largest mineral database and mineralogical reference website on the internet. It is used by amateur mineral collectors alike, it contains a significant database of minerals and mineral photographs, is updated by registered users adding and editing entries. As of 2016, it included: 45,289 mineral names, of which 5,091 are minerals or mineraloids recognized by the International Mineralogical Association. 261,955 mineral localities worldwide, with information on 903,204 mineral occurrences within these sites. Over 647,000 photos of minerals have been uploaded, arranged into galleries from collectors and institutions worldwide who wish to share their mineral collections online. 48,657 users edit data. Mindat was started in 1993 as a personal database project by Jolyon Ralph, he developed further versions as a Microsoft Windows application before launching a community-editable database web site in October 2000. Mindat.org is now part of the Hudson Institute of Mineralogy, a 501 not-for-profit educational foundation incorporated in the state of New York.
Jolyon Ralph was awarded the Mineralogical Society of America's Distinguished public service medal in 2011 for his work on Mindat.org. Mindat.org site Mindat.org - 10 years online today
Gold is a chemical element with symbol Au and atomic number 79, making it one of the higher atomic number elements that occur naturally. In its purest form, it is a bright reddish yellow, soft and ductile metal. Chemically, gold is a group 11 element, it is solid under standard conditions. Gold occurs in free elemental form, as nuggets or grains, in rocks, in veins, in alluvial deposits, it occurs in a solid solution series with the native element silver and naturally alloyed with copper and palladium. Less it occurs in minerals as gold compounds with tellurium. Gold is resistant to most acids, though it does dissolve in aqua regia, a mixture of nitric acid and hydrochloric acid, which forms a soluble tetrachloroaurate anion. Gold is insoluble in nitric acid, which dissolves silver and base metals, a property that has long been used to refine gold and to confirm the presence of gold in metallic objects, giving rise to the term acid test. Gold dissolves in alkaline solutions of cyanide, which are used in mining and electroplating.
Gold dissolves in mercury, forming amalgam alloys. A rare element, gold is a precious metal, used for coinage and other arts throughout recorded history. In the past, a gold standard was implemented as a monetary policy, but gold coins ceased to be minted as a circulating currency in the 1930s, the world gold standard was abandoned for a fiat currency system after 1971. A total of 186,700 tonnes of gold exists above ground, as of 2015; the world consumption of new gold produced is about 50% in jewelry, 40% in investments, 10% in industry. Gold's high malleability, resistance to corrosion and most other chemical reactions, conductivity of electricity have led to its continued use in corrosion resistant electrical connectors in all types of computerized devices. Gold is used in infrared shielding, colored-glass production, gold leafing, tooth restoration. Certain gold salts are still used as anti-inflammatories in medicine; as of 2017, the world's largest gold producer by far was China with 440 tonnes per year.
Gold is the most malleable of all metals. It can be drawn into a monoatomic wire, stretched about twice before it breaks; such nanowires distort via formation and migration of dislocations and crystal twins without noticeable hardening. A single gram of gold can be beaten into a sheet of 1 square meter, an avoirdupois ounce into 300 square feet. Gold leaf can be beaten thin enough to become semi-transparent; the transmitted light appears greenish blue, because gold reflects yellow and red. Such semi-transparent sheets strongly reflect infrared light, making them useful as infrared shields in visors of heat-resistant suits, in sun-visors for spacesuits. Gold is a good conductor of electricity. Gold has a density of 19.3 g/cm3 identical to that of tungsten at 19.25 g/cm3. By comparison, the density of lead is 11.34 g/cm3, that of the densest element, osmium, is 22.588±0.015 g/cm3. Whereas most metals are gray or silvery white, gold is reddish-yellow; this color is determined by the frequency of plasma oscillations among the metal's valence electrons, in the ultraviolet range for most metals but in the visible range for gold due to relativistic effects affecting the orbitals around gold atoms.
Similar effects impart a golden hue to metallic caesium. Common colored gold alloys include the distinctive eighteen-karat rose gold created by the addition of copper. Alloys containing palladium or nickel are important in commercial jewelry as these produce white gold alloys. Fourteen-karat gold-copper alloy is nearly identical in color to certain bronze alloys, both may be used to produce police and other badges. White gold alloys can be made with nickel. Fourteen- and eighteen-karat gold alloys with silver alone appear greenish-yellow and are referred to as green gold. Blue gold can be made by alloying with iron, purple gold can be made by alloying with aluminium. Less addition of manganese, aluminium and other elements can produce more unusual colors of gold for various applications. Colloidal gold, used by electron-microscopists, is red. Gold has only one stable isotope, 197Au, its only occurring isotope, so gold is both a mononuclidic and monoisotopic element. Thirty-six radioisotopes have been synthesized, ranging in atomic mass from 169 to 205.
The most stable of these is 195Au with a half-life of 186.1 days. The least stable is 171Au. Most of gold's radioisotopes with atomic masses below 197 decay by some combination of proton emission, α decay, β+ decay; the exceptions are 195Au, which decays by electron capture, 196Au, which decays most by electron capture with a minor β− decay path. All of gold's radioisotopes with atomic masses above 197 decay by β− decay. At least 32 nuclear isomers have been characterized, ranging in atomic mass from 170 to 200. Within that range, only 178Au, 180Au, 181Au, 182Au, 188Au do not have isomers. Gold's most stable isomer is 198m2Au with a half-life of 2.27 days. Gold's least stable isomer is 177m2Au with a half-life of only 7 ns. 184m1Au has three decay paths: β+ decay, isomeric
Provinces and territories of Canada
The provinces and territories of Canada are the sub-national governments within the geographical areas of Canada under the authority of the Canadian Constitution. In the 1867 Canadian Confederation, three provinces of British North America—New Brunswick, Nova Scotia, the Province of Canada —were united to form a federated colony, becoming a sovereign nation in the next century. Over its history, Canada's international borders have changed several times, the country has grown from the original four provinces to the current ten provinces and three territories. Together, the provinces and territories make up the world's second-largest country by area. Several of the provinces were former British colonies, Quebec was a French colony, while others were added as Canada grew; the three territories govern the rest of the area of the former British North America. The major difference between a Canadian province and a territory is that provinces receive their power and authority from the Constitution Act, 1867, whereas territorial governments have powers delegated to them by the Parliament of Canada.
The powers flowing from the Constitution Act are divided between the Government of Canada and the provincial governments to exercise exclusively. A change to the division of powers between the federal government and the provinces requires a constitutional amendment, whereas a similar change affecting the territories can be performed unilaterally by the Parliament of Canada or government. In modern Canadian constitutional theory, the provinces are considered to be sovereign within certain areas based on the divisions of responsibility between the provincial and federal government within the Constitution Act 1867, each province thus has its own representative of the Canadian "Crown", the lieutenant governor; the territories are not sovereign, but instead their authorities and responsibilities come directly from the federal level, as a result, have a commissioner instead of a lieutenant governor. Notes: There are three territories in Canada. Unlike the provinces, the territories of Canada have no inherent sovereignty and have only those powers delegated to them by the federal government.
They include all of mainland Canada north of latitude 60° north and west of Hudson Bay, as well as most islands north of the Canadian mainland. The following table lists the territories in order of precedence. Ontario, New Brunswick, Nova Scotia were the original provinces, formed when several British North American colonies federated on July 1, 1867, into the Dominion of Canada and by stages began accruing the indicia of sovereignty from the United Kingdom. Prior to this and Quebec were united as the Province of Canada. Over the following years, British Columbia, Prince Edward Island were added as provinces; the British Crown had claimed two large areas north-west of the Canadian colony, known as Rupert's Land and the North-Western Territory and assigned them to the Hudson's Bay Company. In 1870, the company relinquished its claims for £300,000, assigning the vast territory to the Government of Canada. Subsequently, the area was re-organized into the province of the Northwest Territories; the Northwest Territories were vast at first, encompassing all of current northern and western Canada, except for the British holdings in the Arctic islands and the Colony of British Columbia.
The British claims to the Arctic islands were transferred to Canada in 1880, adding to the size of the Northwest Territories. The year of 1898 saw the Yukon Territory renamed as Yukon, carved from the parts of the Northwest Territories surrounding the Klondike gold fields. On September 1, 1905, a portion of the Northwest Territories south of the 60th parallel north became the provinces of Alberta and Saskatchewan. In 1912, the boundaries of Quebec and Manitoba were expanded northward: Manitoba's to the 60° parallel, Ontario's to Hudson Bay and Quebec's to encompass the District of Ungava. In 1869, the people of Newfoundland voted to remain a British colony over fears that taxes would increase with Confederation, that the economic policy of the Canadian government would favour mainland industries. In 1907, Newfoundland acquired dominion status. In the middle of the Great Depression in Canada with Newfoundland facing a prolonged period of economic crisis, the legislature turned over political control to the Newfoundland Commission of Government in 1933.
Following Canada's participation in World War II, in a 1948 referendum, a narrow majority of Newfoundland citizens voted to join the Confederation, on March 31, 1949, Newfoundland became Canada's tenth province. In 2001, it was renamed Newfoundland and Labrador. In 1903, the Alaska Panhandle Dispute fixed British Columbia's northwestern boundary; this was one of only two provinces in Canadian history to have its size reduced. The second reduction, in 1927, occurred when a boundary dispute between Canada and the Dominion of Newfoundland saw Labrador increased at Quebec's expense – this land returned to Canada, as part of the province of Newfoundland, in 1949. In 1999, Nunavut was created from the eastern portion of the Northwest Territories. Yukon lies in the western portion of Northern Canada. All t
Northern Ontario is a primary geographic and administrative region of the Canadian province of Ontario. Most of the core geographic region is located on part of the Superior Geological Province of the Canadian Shield, a vast rocky plateau located north of Lake Huron, the French River, Lake Nipissing, the Mattawa River; the statistical region extends south of the Mattawa River to include all of the District of Nipissing. The southern section of this district lies on part of the Grenville Geological Province of the Shield which occupies the transitional area between Northern and Southern Ontario; the extended federal and provincial administrative regions of Northern Ontario have their own boundaries further south in the transitional area that vary according to their respective government policies and requirements. Ontario government departments and agencies such as the Growth Plan for Northern Ontario and the Northern Ontario Heritage Fund Corporation define Northern Ontario as all areas north of, including, the districts of Parry Sound and Nipissing for political purposes, while the federal government, but not the provincial includes the district of Muskoka.
The statistical region has a land area of 806,000 km2 and constitutes 88 per cent of the land area of Ontario, but with just 780,000 people it contains only about six per cent of the province's population. The climate is characterized by extremes of temperature cold in winter and hot in summer; the principal industries are mining and hydroelectricity. For some purposes, Northern Ontario is further subdivided into Northeastern and Northwestern Ontario; when the region is divided in this way, the three westernmost districts constitute "Northwestern Ontario" and the other districts constitute "Northeastern Ontario." Northeastern Ontario contains two thirds of Northern Ontario's population. In the early 20th century, Northern Ontario was called "New Ontario", although this name fell into disuse because of its colonial connotations; those areas which formed part of New France in the pays d'en haut the watersheds of the Ottawa River, Lake Huron and Lake Superior, had been acquired by the British by the Treaty of Paris and became part of Upper Canada in 1791, the Province of Canada between 1840 and 1867.
At the time of Canadian Confederation in 1867, the portion of Northern Ontario lying south of the Laurentian Divide was part of Ontario, while the portion north of the divide was part of the separate British territory of Rupert's Land. The province's boundaries were provisionally expanded northward and westward in 1874, while the Lake of the Woods region remained subject to a boundary dispute between Ontario and Manitoba; the region was confirmed as belonging to Ontario by decision of the Judicial Committee of the Privy Council in 1884, confirmed by the Canada Act, 1889 of the Parliament of the United Kingdom, which set the province's new northern boundary at the Albany River. The remaining northernmost portion of the province, from the Albany River to Hudson Bay, was transferred to the province from the Northwest Territories by the Parliament of Canada in the Ontario Boundaries Extension Act, 1912; this region was established as the District of Patricia, but was merged into the Kenora District in 1927.
The Province of Canada began creating judicial districts in sparsely populated Northern Ontario with the establishment of Algoma District and Nipissing District in 1858. These districts had no municipal function. Nipissing had no district seat until 1895. Up until that date, registry office and higher court services were available at Pembroke in Renfrew County. Nipissing Stipendiary Magistrate and land registrar William Doran established his residence at North Bay in 1885. Following the hotly contested district town election in 1895, North Bay earned the right to become the district seat in the new Provisional District of Nipissing. After the creation of the province of Ontario in 1867, the first district to be established was Thunder Bay in 1871 which until had formed part of Algoma District; the Ontario government was reluctant to establish new districts in the north because the northern and western boundaries of Ontario were in dispute after Confederation. Ontario's right to Northwestern Ontario was determined by the Judicial Committee of the Privy Council in 1884 and confirmed by the Canada Act, 1889 of the Parliament of the United Kingdom.
By 1899 there were seven northern districts: Algoma, Muskoka, Parry Sound, Rainy River, Thunder Bay. Five more northern districts were created between 1907 and 1922: Cochrane, Sudbury and Patricia; the Patricia District was merged into the Kenora District in 1927. Unlike the counties and regional municipalities of Southern Ontario, which have a government and administrative structure and jurisdiction over specified government services, a district lacks that level of administration. Districts are too sparsely populated to maintain a county government system, so many district-based services are provided directly by the provincial government. For example, districts have provincially maintained secondary highways instead of county roads. Statistically, the districts in Northern Ontario are Rainy River, Thunder Bay, Timiskaming, Sudbury and Manitoulin. The