vitamins and macro minerals 2

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Chapter 21: Resources of Minerals and Energy Introduction: Natural Resources And Human History (1) Over one hundred sixty thousand years ago, our ancestors probably began to use flint, chert, and obsidian to make tools  Metals were first used more than 20,000 years ago     Copper and gold were the earliest metals used By 6000 years ago, our ancestors extracted copper by smelting Before another thousand years had passed, they had discovered how to smelt lead, tin, zinc, silver, and other metals Introduction: Natural Resources And Human History (2)     The technique of mixing metals to make alloys came next – Bronze was composed of copper and tin – Pewter was composed of tin, lead, and copper The smelting of iron came much later—about 3300 years ago The first people to use oil instead of wood for fuel were the Babylonians, about 4500 years ago The first people to mine and use coal were the Chinese, about 3100 years ago Mineral Resources (1) Mineral deposits are any volume of rock containing an enrichment of one or more minerals  Mineral resources have three distinctive characteristics:     Occurrences of usable minerals are limited in abundance and localized at places within the Earth’s crust The quantity of a given mineral available in any one country is rarely known with accuracy Deposits of minerals are depleted by mining and eventually exhausted Figure 21.1 Figure 21.2 Mineral Resources (2) Ore is an aggregate of minerals from which one or more minerals can be extracted profitably  “Ore” is an economic term, whereas “mineral deposit” is a geologic term  The economic challenges of ore are to find it, mine it, and refine it as cheaply as possible  The lowest-grade ores ever mined—about 0.5 percent copper—were worked only at a time of high metal prices  Mineral Resources (3)  In 2002, lowest grade of of mineable copper ore is closer to percent  Over production of copper around the world, combined with economic recession, has resulted in the closing of many mines, particularly those exploiting the lowest grades of ores Mineral Resources (4) Sphalerite, galena, and chalcopyrite are ore minerals from which zinc, lead, and copper respectively can be extracted  Ore minerals rarely occur alone   They are mixed with other nonvaluable minerals, collectively termed gangue – Gangue may include quartz, feldspar, mica, calcite, or dolomite Origin Of Mineral Deposits (1) All ores are mineral deposits because each of them is a local enrichment of one or more minerals or mineraloids  Not all minerals deposits are ores  In order for a deposit to form, processes must bring about a localized enrichment of one or more minerals  Figure 21.13 Coal (2) A coal seam is a flat, lens-shaped body having the same surface area as the swamp in which it originally accumulated  Coal seams are found in Utah, Montana, Wyoming, and the Dakotas  Peat formation has been widespread and more or less continuous from the time land plants first appeared about 450 million years ago, during the Silurian Period  Coal (3)  The greatest period of coal swamp formation occurred during the Carboniferous and Permian periods, when Pangaea existed   These periods produced the great coal bed of Europe and the eastern United States The second great period of coal deposition peaked during the Cretaceous period but commenced in the early Jurassic and continued until the mid-Tertiary Petroleum: Oil and Natural Gas   The major use of oil really started about 1847, when a merchant in Pittsburgh, Pennsylvania, started bottling and selling rock oil as a lubricant  In 1852, a Canadian chemist discovered kerosene, a liquid that could be used in lamps  In Romania in 1856, workers were producing 2000 barrels a year  In 1859, the first oil well was drilled in Titusville Pennsylvania; Modern use of gas started in the early seventeenth century in Europe, where gas made from wood and coal was used for illumination Origin of Petroleum (1) Petroleum is a product of the decomposition of organic matter trapped in sediment  Nearly 60 percent of all the oil and gas discovered so far has been found in strata of Cenozoic age  Petroleum migration is analogous to groundwater migration When oil and gas are squeezed out of the shale in which they originated and enter a body a sandstone or limestone, they can migrate easily  Because it is lighter than water, the oil tends to glide upward, until it encounters a trap  Figure 21.14 Figure 21.15 Figure 21.16 Tars  Tar is made of oil that is exceedingly viscous;   The largest known occurrence of tar sand is in Alberta, Canada, where the Athabasca Tar Sand covers an area of 5000 km2 and reaches a thickness of 60 m Similar deposits, almost as large, are known in Venezuela and in Russia Oil Shale The world’s largest deposit of rich oil shale is in Colorado, Wyoming, and Utah  Only oil shale that produces 40 liters of oil per ton are worth mining  The richest shales in the U.S are in Colorado: they produce as much as 240 liters of oil per ton  Production expenses today make exploitation of oil shales in all countries unattractive by comparison to oil and gas  Other Sources of Energy (1) Biomass energy:  Wood and animal dung  Hydroelectric power  Nuclear energy    Heat energy is produced during controlled transformation (fission) of suitable radioactive isotopes Three of the radioactive atoms that keep the Earth hot by spontaneous decay—238U, 235U, and 232Th—can be mined and used to obtain nuclear energy Other Sources of Energy (2)  Geothermal power   Geothermal power is produced by tapping the Earth’s internal heat flux (Zealand, Italy, Iceland and the United States) Energy from winds, waves, tides, and sunlight:    Winds and waves are both secondary expressions of solar energy Winds have been used as an energy source for thousands of years through sails on ships and windmills Steady surface winds have only about 10 percent of the energy the human race now uses Other Sources of Energy (3)  Tides arise from the gravitational forces exerted on the Earth by the Moon and the Sun – If a dam is put across the mouth of a bay so that water can be trapped at high tide, the outward flowing water at low tide can drive a turbine Consumption Rates In North America, each person uses approximately 20 tons of crushed rock, cement, sand and gravel, fertilizer, oil, gas, coal, metals, and other commodities per year  For the world as a whole, the consumption rate is about tons per person per year  About 54 billion tons of material is dug up and used each year  Figure 21.20 [...]... (Na2CO3), sodium sulfate (Na2SO4), and borax (Na2B4O7.1OH2O) Evaporite Deposits (2)  Huge evaporite deposits of sodium carbonate were laid down in the Green River basin of Wyoming during the Eocene Epoch   Oil shales were also deposited in the basin Borax and other boron-containing minerals are mined from evaporite lake deposits in Death Valley and Searled and Borax Lakes, all in California; and. .. fractures that are localized in and around stratovolcanoes  Many famous ore bodies are associated with intrusive igneous rocks    Tin in Cornwall, England, Copper at Butte, Montana, Bingham, Utah, and Bisbee, Arizona Figure 21 B1 Figure 21 B2 Magmatic Mineral Deposits (1) The processes of partial melting and fractional crystallization are two ways of separating some minerals from other  The processes... Lakes, all in California; and in Argentina, Bolivia, Turkey, and China Evaporite Deposits (3) Much more common and important than lake water evaporites are the marine evaporites formed by evaporation of seawater  The most important salts that precipitate from seawater are:   Gypsum (CaSO4.2H2O)  Halite (NaCl) Carnallite (KCl.MgCl2.6H2O)  Evaporite Deposits (4) Low-grade metamorphism of marine... volcanogenic massive sulfide deposits are rich in copper and zinc In black smokers, the rising hydrothermal fluid appears black due to fine particles of iron sulfide and other minerals precipitated from solution as the plume is cooled by contact with cold seawater  The chimney-like structure is composed of pyrite, chalcopyrite, and other ore minerals deposited by hydrothermal solution Hydrothermal... magma is released as the magma rises and cools  Other solutions are formed from rainwater or seawater that circulates deep in the crust  Mineral deposits formed from midocean ridge volcanism are called volcanogenic massive sulfide deposits  Figure 21 .3 Hydrothermal Mineral Deposits (2)  The pyroxene-rich rocks of the oceanic crust yield solutions charged with copper and zinc   As a result, volcanogenic...Origin Of Mineral Deposits (2)  Minerals become concentrated in five ways:   1 Concentration by hot, aqueous solutions flowing through fractures and pore spaces in crustal rock to form hydrothermal mineral deposits 2 Concentration by magmatic processes within a body of igneous rock to form magmatic mineral deposits Origin...  Rapid precipitation and a concentrated mineral deposit are the result Veins formed when hydrothermal solutions deposit minerals in open fractures  Many such veins are found in regions of volcanic activity Figure 21 .5 Hydrothermal Mineral Deposits (5) The famous gold deposits at Cripple Creek, Colorado, were formed in fractures associated with a small caldera  The huge tin and silver deposits in... Tanco pegmatite in Manitoba, Canada, produces much of the world’s cesium, and pegmatites in many countries yield beryl, one of the main ore minerals of beryllium  Magmatic Mineral Deposits (4) Crystal settling, another process of fractional crystallization, is especially important in lowviscosity basaltic magma  One of the first minerals to form is chromite, the main ore mineral of chromium  The dense... dissolved minerals were precipitated from such a slow-moving solution, they would be spread over a large volume of rock and would not be sufficiently concentrated to form an ore  Hydrothermal Mineral Deposits (4)  When a solution flows rapidly, as in an open fracture, or through a mass of shattered rocks, or through a layer of porous tephra where flow is less restricted, cooling can be sudden and can... magmatic, and so such deposits are referred to as magmatic mineral deposits  Magmatic Mineral Deposits (2)  Pegmatites formed by fractional crystallization of granitic magma commonly contain rich concentrations of such elements as:     Lithium Beryllium Cesium Niobium Magmatic Mineral Deposits (3) Much of the world’s lithium is mined from pegmatites such as those at King’s Mountain, North Carolina, and
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