My Science School

Maps are made for many purposes. The details that an airline pilot needs to see, for example, are very different from those needed by a person following a local footpath. In addition to the actual content of the map, it needs to be drawn to an appropriate scale. That means that a distance on the map will need to be multiplied by a certain figure to find the distance on the ground itself. On a scale of 1:10,000, for example, one millimetre on the map will be equivalent to 10,000 millimetres (or 10 metres) in real life. The scale of the map above is shown on the map itself.

The scale of a map is the ratio of a distance on the map to the corresponding distance on the ground. This simple concept is complicated by the curvature of the Earth’s surface, which forces scale to vary across a map. Because of this variation, the concept of scale becomes meaningful in two distinct ways.

The first way is the ratio of the size of the generating globe to the size of the Earth. The generating globe is a conceptual model to which the Earth is shrunk and from which the map is projected. The ratio of the Earth's size to the generating globe's size is called the nominal scale (= principal scale = representative fraction). Many maps state the nominal scale and may even display a bar scale (sometimes merely called a ‘scale’) to represent it.

The second distinct concept of scale applies to the variation in scale across a map. It is the ratio of the mapped point's scale to the nominal scale. In this case 'scale' means the scale factor (= point scale = particular scale).

If the region of the map is small enough to ignore Earth's curvature, such as in a town plan, then a single value can be used as the scale without causing measurement errors. In maps covering larger areas, or the whole Earth, the map's scale may be less useful or even useless in measuring distances. The map projection becomes critical in understanding how scale varies throughout the map. When scale varies noticeably, it can be accounted for as the scale factor. Tissot’s indicatrix is often used to illustrate the variation of point scale across a map.

A map must be as easy to read as possible, which means that symbols and colours can often give more information than words. A key explains what the symbols and colours mean. A map key or legend is included with a map to unlock it. It gives you the information needed for the map to make sense. Maps often use symbols or colors to represent things, and the map key explains what they mean. Map keys are often boxes in the corner of the map, and the information they give you is essential to understanding the map. Symbols in the key might be pictures or icons that represent different things on the map. Sometimes the map might by colored or shaded, and the key explains what the colors and shades mean. The picture here shows an example of a map key for a typical road map.

Sometimes called a legend, a map key is a table that explains what the symbols on a map mean. This helps the person reading the map understand where to find certain items. For example, a map of a mall may have symbols that reveal bathrooms, places to eat, elevators and guest services areas. A map of a city may have symbols for roads, parks, tourist attractions and public transportation stations.

While the person who creates the map can determine which symbols to use, there are some symbols that are universal. For example, a long blue line often indicates a river, while black lines represent roads. A black dot represents a city, while a star is a capital city. Green spaces often represent parks or forests. Airplanes represent airports, and a red cross is a hospital.

Represented by different colors and shapes, map symbols are used to indicate certain terrain features or important locations in a specified area. The reduced representation of a map is rendered useless without the symbols displayed in its key.

Map symbols represent the physical features of land and help the map's reader gain an acute awareness of his surroundings. Chemeketa Community College faculty affirm that the most common map symbols include contour lines, buildings, water features, and forests and clearings. Contour lines are indicators of elevation and are usually brown. Each contour line has a number beside it that indicates "feet above sea level". Buildings, and all other man-made features, are black and have different shapes for inhabited and uninhabited buildings. The color blue easily distinguishes water features, such as streams or lakes. Forests are indicated by the color green. The density of the tree cover depends on the shade of green. Clearings are shown as white, curvy blotches surrounded by green. Faculty at the University of Wisconsin adds map symbols such as two pickaxes forming an "x". This indicates a quarry or a mine. Waterfalls are also shown and mark small waterways with a notch, while large rivers are marked with ripples.

Gerhard Kremer (1512-94) was called Gerardus Mercator, meaning merchant, because he made maps for merchants travelling from country to country. In 1569, he made a world map using a projection that has come to be known as Mercator’s projection. It is a map that seems familiar to us, but in fact it makes countries at the far north and south of the globe appears much larger than they really are.

A Flemish cartographer who invented a system of setting lines of latitude and longitude on charts of the spherical earth, the “Mercator projection,” which has become a standard for maps into modern times. Born in Rupelmonde, a small town in Flanders, he studied at the University of Louvain, where he achieved a master's degree in 1532. Troubled by the conflict of ancient Greek philosophy with Christian doctrine, Mercator studied mathematics, philosophy, geography and astronomy in order to reach some conclusions about the origins and true nature of the world. He was above all fascinated by the developing art of mapmaking, which in his day benefited from the discoveries of explorers and traveling merchants. He became a skilled maker of globes and instruments; under the training of Gemma Frisius and Gaspar Myrica, two men expert in the craft, he also mastered the difficult art of engraving. A workshop set up by the three men turned Louvain into an important center of globe making, cartography, and the production of sextants, telescopes, and other scientific instruments. His far-ranging exploration and questioning of accepted Christian doctrines, however, landed him in trouble with the religious authorities, and in 1544 he was arrested, tried, convicted, and briefly imprisoned on a charge of heresy.

In 1552 Mercator moved to Duisburg, in the Germany duchy of Cleves, where he was appointed a professor of mathematics and also became a land surveyor. In Duisburg, where he remained for the rest of his life, he helped to found a grammar school and continued his work in cartography. After publishing a map of Europe in 1554 and then several other local maps of Britain and the European continent, his reputation spread. He also developed a new method of producing globes, in which he pasted on the sphere printed maps that were cut to fit by tapering their edges toward the top and bottom.

Mercator was appointed by the Duke of Cleves as an official court cartographer. He perfected his system of marking parallel lines on a map to indicate degrees of longitude that could be applied to navigation charts and allow ship captains to more accurately follow their course at sea. He first used this system on a map of the world he completed in 1569. In the 1570s he began producing an atlas, a collection that included the maps of the ancient Greek astronomer Ptolemy as well as his own maps covering France, Germany, Italy, the Netherlands, eastern Europe, Greece, and the British Isles. This work, which he completed over the span of more than twenty years, was finally published by his son after his death.

Globes can represent the Earth in miniature, with features shown in a true relationship to each other, but they are not practical to put in your pocket for an afternoon walk. Paper maps are much easier to use, but an adjustment needs to be made in order to show a curved land surface on a flat map. The adjustment chosen is called a projection. Several different projections can be used, depending on the purpose of the map.

A map projection is a method for taking the curved surface of the earth and displaying it on something flat, like a computer screen or a piece of paper. Map makers have devised methods for taking points on the curved surface of the earth and "projecting" them onto a flat surface. These methods enable map makers to control the distortion that results from creating a flat map of the round earth.

Every map projection has some distortion. Equal area projections attempt to show regions that are the same size on the Earth the same size on the map but may distort the shape. Conformal projections favor the shape of features on the map but may distort the size.

A map is a symbolic representation of selected characteristics of a place, usually drawn on a flat surface. Maps present information about the world in a simple, visual way. They teach about the world by showing sizes and shapes of countries, locations of features, and distances between places. Maps can show distributions of things over Earth, such as settlement patterns. They can show exact locations of houses and streets in a city neighborhood.

Mapmakers, called cartographers, create maps for many different purposes. Vacationers use road maps to plot routes for their trips. Meteorologists—scientists who study weather—use weather maps to prepare forecasts. City planners decide where to put hospitals and parks with the help of maps that show land features and how the land is currently being used. Some common features of maps include scale, symbols, and grids.

A map is similar to an aerial view of the Earth. The landscape is shown as though you are looking down on it, so that the relation of one place to another is clear. But maps are much more than simply bird’s-eye views. A great deal of information about the names of places and what they are like can be given in words, numbers and symbols. Although maps are more than aerial snapshots, surveying by plane or satellite has helped mapmakers considerably. Surveying on the ground is time-consuming and may be difficult in remote places. Computer-controlled aerial surveying can give very accurate results and show overall changes in such features as vegetation and coastlines much more clearly than traditional methods.

We often see the finished product of a map folded into an issue of Canadian Geographic or posted up on a wall. But how are these data-rich works of art created?

Modern cartographer’s tools allow mapmakers to show more detail than ever before in a single map with attractive, creative elements. However, this wasn’t always so.

In the early years of Canadian Geographic, from the 1930s to the ‘50s, maps were often hand drawn with no more than some surveying data and perhaps an aerial photo or two. Colour was reserved for only a few choice maps, often those linked to an advertisement, and cartographers were rarely credited.

Now, satellite data, aerial photography and computer programs all go into making a modern Canadian Geographic map. Satellite data, also known as remote sensing data, provides a wealth of information to our cartographers, including geological characteristics of land, such the height and size of mountains, and a variety of climatic information, such as sea temperatures, weather patterns and more. Aerial photography has helped mapmakers since the 1940s and offers a visual sense of the landscape and sort of a ‘big-picture’ look at the satellite data. A variety of computer programs organize the data, help plot the data and shape a landscape as well as aid in the design process.

Deep deposits are reached by driving a shaft vertically into the ground. Miners descend the shaft in a lift. An air shaft takes fresh air down into the mine, where poisonous gases may accumulate. Trucks carry the mined material to a freight lift, which brings them to the surface. Trucks may also be used to take miners to the nearest deposits. Drift mines are dug where the deposit lies in an outcrop of rock near the surface. The seam can be mined directly from the surface, which is often on the slope of a hill.

Deep deposits are reached by driving a shaft vertically into the ground. Miners descend the shaft in a lift. An air shaft takes fresh air down into the mine, where poisonous gases may accumulate. Trucks carry the mined material to a freight lift, which brings them to the surface. Trucks may also be used to take miners to the nearest deposits. Drift mines are dug where the deposit lies in an outcrop of rock near the surface. The seam can be mined directly from the surface, which is often on the slope of a hill.

There are underground mines all over the world presenting a kaleidoscope of methods and equipment. There are approximately 650 underground mines, each with an annual output that exceeds 150,000 tonnes, which account for 90% of the ore output of the western world. In addition, it is estimated that there are 6,000 smaller mines each producing less than 150,000 tonnes. Each mine is unique with workplace, installations and underground workings dictated by the kinds of minerals being sought and the location and geological formations, as well as by such economic considerations as the market for the particular mineral and the availability of funds for investment. Some mines have been in continuous operation for more than a century while others are just starting up.

Mines are dangerous places where most of the jobs involve arduous labour. The hazards faced by the workers range from such catastrophes as cave-ins, explosions and fire to accidents, dust exposure, noise, heat and more. Protecting the health and safety of the workers is a major consideration in properly conducted mining operations and, in most countries, is required by laws and regulations.

The underground mine is a factory located in the bedrock inside the earth in which miners work to recover minerals hidden in the rock mass. They drill, charge and blast to access and recover the ore, i.e., rock containing a mix of minerals of which at least one can be processed into a product that can be sold at a profit. The ore is taken to the surface to be refined into a high-grade concentrate.

Working inside the rock mass deep below the surface requires special infrastructures: a network of shafts, tunnels and chambers connecting with the surface and allowing movement of workers, machines and rock within the mine. The shaft is the access to underground where lateral drifts connect the shaft station with production stops. The internal ramp is an inclined drift which links underground levels at different elevations (i.e., depths). All underground openings need services such as exhaust ventilation and fresh air, electric power, water and compressed air drains and pumps to collect seeping ground water, and a communication system.

Although there are enormous reserves of iron and aluminium in the Earth’s crust, other metals, such as tin, lead, silver, zinc, mercury and platinum are not so plentiful. Some further sources of such metals are known, but at present it would prove too expensive to reach them. As with other non-renewable resources, it is important that we recycle metals or use other materials where possible.

Minerals make up most of what we use to build, manufacture and stand on — including rocks and soil — so if we really ran out of minerals, we'd all be scrambling for a spot on the planet's shrunken surface areas.

But if you were worried about running out of a single mineral important for industry, then you probably can breathe easy. Most of the minerals we use a lot are very abundant. Iron, for example, makes up about 32 percent of Earth's crust, so you'd have to worry about finding a place to stand long before worrying about whether we can keep making steel.

But if we were to run out of a mineral — as in, exhaust our supply — it probably wouldn't be because there's none of it left on Earth. The problem would be that the processes used to extract it have become too expensive, difficult or harmful to make mining worthwhile. Even then, as mining technology advances, previously inaccessible minerals will become available and lower-producing ores will be processed more efficiently.

But still, what are we working with here? What are minerals? How big is our planet's supply?

Minerals are substances formed naturally underground — think coal, quartz, salt. Like everything else, they're made of elements, basic substances that can't be broken down into simpler substances. Some minerals are single elements, like gold. When we're assessing amounts of minerals in the world, it's more complicated than there being a finite amount of resources that we're using up over time. World mineral reserves are constantly revised based on estimated consumption and current production abilities. For example, in 1950, the estimated copper reserves totaled 100 million metric tons. Over the next 50 years, world copper producers extracted 339 million tons — by 1950 standards we should have run out of copper three times over. For most minerals, supplies have actually increased during the 20th century even though we're using them up faster than ever.

So it's unlikely that Earth will ever run out of minerals. But will people ever experience mineral shortages?

In a sense we're always facing mineral shortages. Shortfalls and reduced production stimulate new mines, new technological innovations and lower standards for what counts as high-quality ore. We're also using a wider array of minerals. More than 60 different elements can be used to build a single computer chip. A lot of these are minerals that never had industrial applications until 20 or 30 years ago, and they're produced in such small quantities that they're much more susceptible to supply risks.

Opencast mines are used when the deposit lies near the surface. Overlying earth and rock can be moved by machine or washed away with water. Although opencast mining is cheaper than digging deep mines, some people feel that the environmental costs of it are high, as large areas of land are laid bare and wildlife destroyed. Nowadays great attention is often paid to landscaping the area after an opencast mine has been abandoned. Many are made into parks or wildlife refuges. Planting the areas also helps to stabilize heaps of spoil.

Opencast mining operation involves generation of massive mine waste, altering the existing landscapes, alterations to drainage patterns etc. As a result, significant areas of land are degraded and existing ecosystems are replaced by undesirable wastes. To mitigate the impact on environment, a structured and adoptable environment management practice is being continuously developed at NLCIL. Eco-friendly mining can be broadly brought up under conservation of natural resources, prevention and regulation of polluting activities and action plans for eco regeneration.

Opencast mining operations involve huge quantities of overburden removal, dumping and backfilling in excavated areas. A substantial increase in the rate of accumulation of waste dumps in recent years has resulted in greater height of the dump for minimum ground cover area and also given rise to danger of dump failures. Further, steeper open-pit slopes are prone to failure. These failures lead to loss of valuable human life and damage to mining machinery. There is a need for continuous monitoring of dump and pit slopes, as well as for providing early warning before the occurrence of slope failure. Different technologies have been developed for slope monitoring. After studying the features and limitations of existing slope monitoring systems, it determined that there is a need to provide a reliable slope stability monitoring and prediction system by using a solar power-based long-range wireless sensor network for continuous monitoring of different prevailing parameters of slope stability. An accurate prediction of slope failure using a multiparameters-based prediction model is required for giving warning per the danger levels of impending slope stability. Considering the requirement, a slope failure monitoring and prediction system has been developed by the authors, using a wireless sensor network for the continuous monitoring of slope failure and to provide early warnings. The chapter describes details of slope stability mechanism, parameters affecting slope failure and triggering aspects, monitoring systems, prediction software, and laboratory experiments for calibrating geosensors and field installation of the developed system.

For practical purposes, the Earth’s crust is the only source of minerals. There are, of course, huge amounts of minerals in the Earth’s core and in space, but at the moment it is not possible for us to reach and use them.

Hard rock minerals could be mined from an asteroid or a spent comet. Precious metals such as gold, silver, and platinum group metals could be transported back to Earth, while iron group metals and other common ones could be used for construction in space.

Difficulties include the high cost of spaceflight, unreliable identification of asteroids which are suitable for mining, and ore extraction challenges. Thus, terrestrial mining remains the only means of raw mineral acquisition used today. If space program funding, either public or private, dramatically increases, this situation may change as resources on Earth become increasingly scarce compared to demand and the full potentials of asteroid mining—and space exploration in general—are researched in greater detail.

Asteroid mining could shift from sci-fi dream to world-changing reality a lot faster than you think. Planetary Resources deployed its first spacecraft from the International Space Station last month, and the Washington-based asteroid-mining company aims to launch a series of increasingly ambitious and capable probes over the next few years.

The goal is to begin transforming asteroid water into rocket fuel within a decade, and eventually to harvest valuable and useful platinum-group metals from space rocks. "After that, I think it's going to be how the market develops," Lewicki told Space.com, referring to the timeline for going after asteroid metals.

"If there's one thing that we've seen repeat throughout history, it's, you tend to overpredict what'll happen in the next year, but you tend to vastly underpredict what will happen in the next 10 years," he added. "We're moving very fast, and the world is changing very quickly around us, so I think those things will come to us sooner than we might think."

In deep mines, water can pose a great danger, undermining layers of rock and causing collapses and flooding, but other types of mining use water to great advantage. Sulphur, for example, can be mined in an unusual process using water. Three pipes of different sizes, one inside another, are drilled into the sulphur reserves. Then extremely hot water, under pressure, is pumped down the outer pipe. This melts the sulphur. Compressed air is then pumped down the central pipe, causing the melted sulphur to move up the middle pipe to the surface. This system was developed by an American engineer, Herman Frasch (1851-1914).

Mining water use is water used for the extraction of minerals that may be in the form of solids, such as coal, iron, sand, and gravel; liquids, such as crude petroleum; and gases, such as natural gas. The category includes quarrying, milling of mined materials, injection of water for secondary oil recovery or for unconventional oil and gas recovery (such as hydraulic fracturing), and other operations associated with mining activities. Dewatering is not reported as a mining withdrawal unless the water was used beneficially, such as dampening roads for dust control.

During some mining activities, particularly gold mining and dredging, water is used for sluicing and flushing out minerals. In most mining operations the majority of this water is recycled, so water loss from rivers and streams is minimised. Water take (abstraction) can be more pronounced where dredging occurs near the riverbed. Loss of water may reduce in stream habitat, elevate water temperatures, and increase summer algal blooms, which may affect invertebrate and mahinga kai communities.

Mountaineers find it time-consuming and difficult to brew a good cup of tea or cook food, especially as they climb higher. You just can’t make your usual cup that cheers on the top of Mount Everest.

Water normally starts boiling when it reaches a temperature of 100  (or 212 ). But this is true only if you are at sea level. As you go higher, due to a fall in the atmospheric pressure, water starts boiling at a lower temperature. (70  or 158  on the summit of Mount Everest!)

This heat is not enough to extract the best flavour from the tea leaves. Cooking in a saucepan or pressure cooker also takes much longer on mountain tops.

 

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For mining to be economical, minerals need to be found in high concentrations. Sometimes they occur in seams. These are layers of minerals or mineral ores occurring between other rocks. In different parts of the world, rocks dating from various periods of the Earth’s history are nearest the surface. This gives mineralogists their first clue as to the minerals that may be found within them.

Natural resources, or commodities, are the raw inputs that are used to manufacture and produce all of the products in the world. Commodities themselves, which include those extracted from the earth and those that have, yet to be extracted, are worth trillions of dollars. Here are the top countries with the most natural resources and their total estimated value, according to World Atlas.?

 Australia

Australia earns $19.9 trillion U.S. dollars from mining, and it is number 10 on the list. Australia is known for its large reserves of coal, timber, copper, iron ore, nickel, oil shale, and rare earth metals and mining is the primary industry. Australia is also one of the leaders in uranium and gold mining. The country has the largest gold reserves in the world, and it supplies over 14% of the world's gold demand and 46% of the world's uranium demand. Australia is the top producer of opal and aluminum.1? The country is about 80% the size of the United States.

 Democratic Republic of Congo

Mining is the primary industry of the Democratic Republic of Congo (DRC) also. In 2009, the DRC had over $24 million in mineral deposits including the largest coltan reserve and huge amounts of cobalt. The DRC also has large copper, diamond, gold, tantalum, and tin reserves, and over a million tons of lithium as estimated by the American geological survey. In 2011, according to the latest data, there were over 25 international mining firms in the DRC.

Venezuela

This South American country has an estimated $14.3 trillion worth of natural resources. It is the leading exporter of bauxite, coal, gold, iron ore, and oil. The country's oil reserves are greater than those of the United States, Canada, and Mexico combined. Venezuela is the third largest producer of coal after Brazil and Colombia. It also has the eighth largest reserves of natural gas accounting for 2.7% of the global supply. Venezuela also has the second-largest reserves of gold deposits.

The United States

Mining is a primary industry in the United States. In 2015, total metal and coal reserves in the country were estimated to be $109.6 billion. The United States is the leading producer of coal and has been for decades, and it accounts for just over 30% of global coal reserves and has huge amounts of timber. Total natural resources for the United States are approximately $45 trillion, almost 90% of which are timber and coal. Other resources include substantial copper, gold, oil, and natural gas deposits.

Brazil

Brazil has commodities worth $21.8 trillion including gold, iron, oil, and uranium. The mining industry focuses on bauxite, copper, gold, iron, and tin. Brazil has the largest gold and uranium deposits in the world, and is the second largest oil producer. However, timber is the most valuable natural resource, and the nation accounts for over 12.3% of the world's timber supplies.1?

Russia

Russia's total estimated natural resources are worth $75 trillion. The country has the biggest mining industry in the world producing mineral fuels, industrial minerals, and metals. Russia is a leading producer of aluminum, arsenic, cement, copper, magnesium metal and compounds, nitrogen, palladium, silicon, and vanadium. The nation is the second-largest exporter of rare earth minerals.1?

India

India's mining sector contributes 11% of the country's industrial GDP and 2.5% of total GDP. The mining and metal industry was worth over $106.4 billion in 2010. The nation's coal reserves are the fourth largest in the world. India's other natural resources include bauxite, chromite, diamonds, limestone, natural gas, petroleum, and titanium ore. India provides over 12% of global thorium, over 60% of global mica production and is the leading producer of manganese ore.

Canada

Third on the list of countries with the most natural resources is Canada. Overall, the country has an estimated $33.2 trillion worth of commodities and the third largest oil deposits after Venezuela and Saudi Arabia. The commodities that the country owns include industry minerals, such as gypsum, limestone, rock salt, and potash, as well as energy minerals, such as coal and uranium. Metals in Canada include copper, lead, nickel, and zinc, and precious metals are gold, platinum and silver. Canada is the leading supplier of natural gas and phosphate and is the third largest exporter of timber.

Saudi Arabia

Saudi Arabia has 20% of the world's oil reserves, second in the world. Oil was discovered here in 1938, and the nation has been a leading oil exporter ever since with its economy depending on oil exports. It also has the sixth-largest natural gas reserves. Overall, the country has about $34.4 trillion worth of natural resources. Saudi Arabia's other natural resources include copper, feldstar, phosphate, silver, sulfur, tungsten, and zinc. Saudi Arabia is a small country, roughly the size of Alaska.

China

China is number one on the list for having the most natural resources estimated to be worth $23 trillion. Ninety percent of resources are coal and rare earth metals. However, timber is another major natural resource of China. Other resources that China produces are antimony, coal, gold, graphite, lead, molybdenum, phosphates, tin, tungsten, vanadium, and zinc. China is the world's second largest producer of bauxite, cobalt, copper, manganese, and silver. It also has chromium and gem diamond.

Peat is partly carbonized vegetable matter, which has decomposed in water. If placed under enormous pressure for millions of years, peat would become coal. Although it does not give off as much heat as coal or oil does when burned, peat is still a useful fuel in some parts of the world, where it is dug from peat-bogs. Peat has also been much prized by gardeners for improving the condition of soil.

Peat is the surface organic layer of a soil that consists of partially decomposed organic matter, derived mostly from plant material, which has accumulated under conditions of water logging, oxygen deficiency, high acidity and nutrient deficiency.

In temperate, boreal and sub-arctic regions, where low temperatures (below freezing for long periods during the winter) reduce the rate of decomposition, peat is formed mainly from bryophytes (mostly sphagnum mosses), herbs, shrubs and small trees.

In the lowland humid tropics, peat is derived mostly from rain forest trees (leaves, branches, trunks and roots) under near constant annual high temperatures.

In other geographical regions peat can be formed from other species of plants that are able to grow in water-saturated conditions. For example, in New Zealand peat is formed from members of the Restionaceae while in tropical coastal fringes peat is formed in mangrove. New types of peat may still be found.

Definitions of peat vary across disciplines and between authorities for different purposes and there is no universal agreement that is applicable in all circumstances. This is unfortunate because it affects estimates of the area of peat land and determination of important attributes of peat, especially volume and carbon content.

There is disagreement on the minimum thickness of the soil surface organic layer and the minimum percentage of organic matter in it between different definitions of peat. For example, according to the U.S. Department of Agriculture Soil Classification peat is an organic soil (Histosol) that contains a minimum of 20% organic matter increasing to 30% if as much as 60% of the mineral matter is clay. Other authorities have adopted definitions of peat with organic matter content higher than 30% and thickness greater than 30cm.

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Strictly speaking, all “minerals” are obtained by mining, as that is one meaning of the word, although it is sometimes used to refer to other inorganic substances. Mining usually involves digging in the Earth’s crust, although a few minerals, such as gold, sometimes come to the surface naturally and are found in rivers or on the seashore. Metals, precious and semi-precious stones, and minerals such as sulphur and salt are all obtained by mining.

The location and shape of the deposit, strength of the rock, ore grade, mining costs, and current market price of the commodity are some of the determining factors for selecting which mining method to use.

Higher-grade metallic ores found in veins deep under the Earth’s surface can be profitably mined using underground methods, which tend to be more expensive. Large tabular-shaped ore bodies or ore bodies lying more than 1,000 feet (300 m) below the surface are generally mined underground as well. The rock is drilled and blasted, then moved to the surface by truck, belt conveyor, or elevator. Once at the surface, the material is sent to a mill to separate the ore from the waste rock.

Lower grade metal ores found closer to the surface can be profitably mined using surface mining methods, which generally cost less than underground methods. Many industrial minerals are also mined this way, as these ores are usually low in value and were deposited at or near the Earth’s surface. In a surface mine, hard rock must be drilled and blasted, although some minerals are soft enough to mine without blasting.

Placer mining is used to recover valuable minerals from sediments in present-day river channels, beach sands, or ancient stream deposits. More than half of the world’s titanium comes from placer mining of beach dunes and sands. In placer operations, the mined material is washed and sluiced to concentrate the heavier minerals.

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The rocks in which deposits of crude (unrefined) oil are found may be hundreds of meters beneath the soil or the sea bed. In either case, a shaft must be drilled down to the deposits. On land, the drill can be set up on a steel structure called a derrick. At sea, a drilling platform is needed. This may have legs that stand on the sea bed or, in very deep water; the drilling platform may float on the surface. Floating platforms must still be anchored firmly to the sea bed so that they can withstand high winds and tempestuous seas.

Conventional oil is extracted from underground reservoirs using traditional drilling and pumping methods. Conventional oil is a liquid at atmospheric temperature and pressure, so it can flow through a wellbore and a pipeline – unlike bitumen (oil sands oil) which is too thick to flow without being heated or diluted. It’s easier and less expensive to recover conventional oil and it requires less processing after extraction. Conventional oil development is both land-based and offshore.

Unconventional oil cannot be recovered using conventional drilling and pumping methods. Advanced extraction techniques, such as oil sands mining and in situ development, are used to recover heavier oil that does not flow on its own. Oil found in geological formations that make it more difficult to extract, such as light tight oil (LTO), is also called unconventional oil because non-traditional techniques are needed to extract the oil from the underground reservoir. Light tight oil is found throughout much of the Western Canadian Sedimentary Basin (WCSB), plus in Central and Eastern Canada. LTO is found deep below the earth’s surface, primarily within low-permeability rock formations including shale, sandstone and mudstone reservoirs. This kind of oil extraction uses horizontal drilling and hydraulic fracturing.

The Canadian regions with tight oil reservoirs include the Bakken, which is found primarily in Saskatchewan; several fields in Alberta including Cardium and Viking; and the Montney and Duvernay in Alberta and B.C.

Surface mining is used when oil sands deposits lie within 70 meters (200 feet) of the earth’s surface. Twenty per cent of oil sands reserves are close enough to the surface to be mined. Large shovels scoop oil sand into haul trucks that transport it to crushers where large clumps are broken down. The oil sand is then mixed with hot water and pumped by pipeline to a plant called an upgraded, where the bitumen (oil) is separated from the other components such as sand, clay and water.

Tailings ponds are common in all types of surface mining around the world. In the oil sands, tailings – consisting of water, sand, clay and trace amounts of oil – are pumped to ponds where the sand and clay gradually settle to the bottom. Water near the top is reused in the mining and bitumen separation process.

Once a tailings pond is no longer needed, it is reclaimed. Oil sands companies that have mining operations are researching many techniques to solidify the tailings faster so the ponds can be dried out, re-surfaced with soil, and planted with local tree and shrub species.

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