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Earth Resources 2

Terms

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The universe began...
around 13.7 billion years ago, with the "big bang." Since then, it has expanded to form galaxies, stars, and planets.
The nebular hypothesis
The nebular hypothesis holds that the solar nebula is the gaseous cloud or accretion disc from which Earth's solar system is believed to have formed. The solar nebula is believed to have had an initial diameter of 100 AU and a mass believed to be 2-3 times the Sun's current mass. Over time, gravity caused the cloud to condense and, as density and pressure increased, a protostar emerged at the centre of the nebula. The early system was heated by friction; fusion would not occur for some time. Due to the conservation of angular momentum, the nebula did not fully collapse upon itself, instead forming a disk. Protoplanetary discs emerged in orbit around the protosun. Within this system, lighter elements such as hydrogen and helium were driven out of the central regions by solar wind and radiation pressure during a highly active T Tauri phase, leaving behind heavier elements and dust particles, which clumped into planetesimals and protoplanets. In the outer part of the solar nebula, ice and volatile gases were able to survive. As a result, the inner planets are formed of minerals, while the outer planets are more gaseous or icy.

After about 100 million years, the heat within the protosun reached such a level that thermonuclear reactions began to occur - the protosun became the Sun. At about the same time, the innermost planets formed, approximately 4.6 billion years ago. The moons of the gas giants are believed to have formed in a roughly analogous process, coalescing from an accretion disk which formed as the giant planets themselves were forming. In contrast, the most commonly accepted theory for the formation of Earth's moon is the giant impact theory, where the moon was formed in a collision with a Mars-sized object.
Diversity of the Planets
Terrestrial planets: iron rich cores mantled in silicate.

jovian planets: huge gaseous balls

Pluto: Mixture of rock and ice(very far away and hard to study.)
Four factors leading to heating and melting in the earth's history
1. Accretion of meter sized bodies.

2. collisions-transfer of kinetic energy into heat.

3. compression

4. radioactivity of elements(e.g. uranium, potassium, and thorium)
The Core
About 100-200 million after initial accretion, temparatures in the earth reach the melting point of iron.

Iron melts-pulled to the center "core" (The cor is 1/6 of earths volume, 1/3 of it's mass)

gravitational energy releases more heat.
The formation of the moon occurred about ___ billion years ago.
4.5
The moon was created when...
an impacter or "mars-sized body" collided with the earth.
Global chemical differentiation begins ___ billion years ago.
4.3
Chemical Differentiation
Continents: light, buoyant magmas that floated up from the mantle, often modified by surfaces processes.

Oceans and Atmosphere: Fluid outer layers made of volatile gases from the interior(and perhaps from comets), The oceanic crust is made out of buoyant stuff than the continental matter.

Crust(Mantle(Liquid Iron Core(solid inner iron core)
________ is the chief process that drives the movement of the earth's mantle.
convection
A rock is...
a naturally-occurring solid composed of one or more minerals.
Three types of rocks
1) igneous rocks: Crystallized from molten rock (magma or lava).

2) Sedimentary rock: Formed from accumulations of sediment on the earths surface.

3) Metamorphic rock: formed by transformation of existing rocks by heat and pressure.
The Geologic timescale
divisions in the geologic time scale are based on variation in the fossil record.
520 million years ago to 50 million years ago ________ were the dominant species on earth.
trilobites
Natural glass is usually...
blackish gray to red in color.
Types of sedimentary rock
1. clastic sedimentary rocks are formed by the accumulation and consolidation of pieces of previously existing rocks.

2)Chemical sedimentary rocks are fromed by chemical precipitation from solution.
Metamorphic rocks
rocks formed by the transformation of previously existing rocks in the solid state due to increased temperature and pressure.
There are ______ recognized minerals found on earth.
3,500
Mineral
A naturally occuring solid crystalline substance, generally inorganic, with specific chemical composition. (glass and coal are not minerals, because they lack an organized crystalline structure)
Fe+O+Si+Mg make up ___% of the whole earth.
93%
Si+O+Al make up ___% of the crust.
82%
The single most abundant type of minerals on the earth, making up 70% of the earth's crust are______________.
Silicates; framework silicate structures such as feldspar and quartz. Other types of silicate minerals are Olivine, the Pyroxene group, the Amphibole group (example: hornblende), and Micas such as biotite and muscovite.
Asbestos refers to
any number of minerals that grow in a like manner.
The sigle most abundant element in the earth's crust is _______.
oxygen
The single most abundant element in the whole earth is _______.
Iron
The second most abundant type of minerals on the earth.
carbonates; which are a major component of limestone
Three major types of carbonates
calcite, aragonite, and dolomite
Oxide class
Oxides are extremely important in mining as they form many of the ores from which valuable metals can be extracted. They commonly occur as precipitates close to the Earth's surface, oxidation products of other minerals in the near surface weathering zone, and as accessory minerals in igneous rocks of the crust and mantle. Common oxides include hematite (iron oxide), magnetite (iron oxide), chromite (chromium oxide), spinel (magnesium aluminium oxide - a common component of the mantle), rutile (titanium dioxide), and ice (hydrogen oxide). The oxide class includes the oxide and the hydroxide minerals.
Classes of minerals
1) Silicate class
2) Carbonate class
3) Sulfate class
4) Halide class
5) Oxide class
6) Sulfide class
7) Phosphate class
8) Element class
Silicate class
The largest group of minerals by far are the silicates, which are composed largely of silicon and oxygen, with the addition of ions such as aluminium, magnesium, iron, and calcium. Some important rock-forming silicates include the feldspars, quartz, olivines, pyroxenes, amphiboles, garnets, and micas.
Carbonate class
The carbonate minerals consist of those minerals containing the anion (CO3)2- and include calcite and aragonite (both calcium carbonate), dolomite (magnesium/calcium carbonate) and siderite (iron carbonate). Carbonates are commonly deposited in marine settings when the shells of dead planktonic life settle and accumulate on the sea floor. Carbonates are also found in evaporitic settings (e.g. the Great Salt Lake, Utah) and also in karst regions, where the dissolution and reprecipitation of carbonates leads to the formation of caves, stalactites and stalagmites. The carbonate class also includes the nitrate and borate minerals.
Sulfate class
Sulfates all contain the sulfate anion, in the form SO42-. Sulfates commonly form in evaporitic settings where highly saline waters slowly evaporate, allowing the formation of both sulfates and halides at the water-sediment interface. Sulfates also occur in hydrothermal vein systems as gangue minerals along with sulfide ore minerals. Another occurrence is as secondary oxidation products of original sulfide minerals. Common sulfates include anhydrite (calcium sulfate), celestite (strontium sulfate), barite (barium sulfate), and gypsum (hydrated calcium sulfate). The sulfate class also includes the chromate, molybdate, selenate, sulfite, tellurate, and tungstate minerals.
Halide class
The halides are the group of minerals forming the natural salts and include fluorite (calcium fluoride), halite (sodium chloride), sylvite (potassium chloride), and sal ammoniac (ammonium chloride). Halides, like sulfates, are commonly found in evaporitic settings such as playa lakes and landlocked seas such as the Dead Sea and Great Salt Lake. The halide class includes the fluoride, chloride, and iodide minerals.
Sulfide class
Many sulfides are economically important as metal ores. Common sulfides include pyrite (iron sulfide - commonly known as fools' gold), chalcopyrite (copper iron sulfide) and galena (lead sulfide). The sulfide class also includes the selenides, the tellurides, the arsenides, the antimonides, the bismuthinides, and the sulfosalts (sulfur and a second anion such as arsenic).
Phosphate class
The phosphate mineral group actually includes any mineral with a tetrahedral unit AO4 where A can be phosphorus, antimony, arsenic or vanadium. By far the most common phosphate is apatite which is an important biological mineral found in teeth and bones of many animals. The phosphate class includes the phosphate, arsenate, vanadate, and antimonate minerals.
Element class
The Elemental group includes metals and intermetallic elements (gold, silver, copper), semi-metals and non-metals (antimony, bismuth, graphite, sulfur). This group also includes natural alloys, such as electrum (a natural alloy of gold and silver), phosphides, silicides, nitrides and carbides (which are usually only found naturally in a few rare meteorites).
The popular name for the sulfide mineral pyrite is _________.
fool's gold
________ dehydrated becomes plaster/sheetrock.
Gypsum
rocks do not melt at one temparature like ice, because...
they much more chemically complex and variant, thus different mineral melt at differnt temperatures.
Factors effecting the the melting of minerals
1)Pressure: increased pressure raises melting points.

2)water content: increased water content lowers melting point.

3)composition: Some minerals melt at lower temperatures than others.
biotite and muscovite are often refered to as _______.
sheet silicates
Where do magmas form?
1)Divergent plate margins

2)convergent plate margins

3)mantle plumes/hot spots
During the generation of magmas at divergent plate margins...
1) partialy melted asthenosphere (peridotite) rises at spreading centers.

2) decompression melting of up to 15% of the rock form mafic magma.
asthenosphere
The asthenosphere (from an invented Greek a + ''sthenos "without strength") is the region of the Earth between 100-200 km below the surface — but perhaps extending as deep as 400 km — that is the weak or "soft" zone in the upper mantle. It lies just below the lithosphere, which is involved in plate movements and isostatic adjustments. In spite of its heat, pressures keep it plastic, and it has a relatively low density. Seismic waves, the speed of which decrease with the softness of a medium, pass relatively slowly though the asthenosphere, the cue that originally alerted seismologists to its presence; thus it has been given the name low-velocity zone.

Under the thin oceanic plates the asthenosphere is usually much nearer the seafloor surface, and at mid-ocean ridges it rises to within a few kilometres of the ocean floor.

The upper part of the asthenosphere is believed to be the zone upon which the great rigid and brittle lithospheric plates of the Earth's crust move about. Due to the temperature and pressure conditions in the asthenosphere, rock becomes ductile, moving at rates of deformation measured in cm/yr over lineal distances eventually measuring thousands of kilometers. In this way, it flows like a convection current, radiating heat outward from the Earth's interior. Above the asthenosphere, at the same rate of deformation, rock behaves elastically and, being brittle, can break, causing faults. The rigid lithosphere is thought to "float" or move about on the slowly flowing asthenosphere, creating the movement of crustal plates described by Plate tectonics theory.
During the generation of magmas at convergent plate margins...
1) subduction drags oceanic lithosphere beneath the adjacent plate.

2) Water from the seafloor basalt and sediments causes melting of the mantle.
Magmas at ocean-continent boundaries...
1)Also called "continental arc" magmas. Examples include the Andaean volcanos, and the US cascades.

2) Show the entire range of compositions from mafic to felsic, due to the mixing of magmaswith the continental crust as they rise.
subduction
Subduction zones mark sites of convective downwelling of the Earth's lithosphere. Subduction zones exist at convergent plate boundaries where one plate of oceanic lithosphere converges with another plate and sinks below into the mantle. It is at subduction zones that the Earth's lithosphere, oceanic crust, sedimentary layers, and trapped water are recycled into the deep mantle. Earth is the only planet where subduction is known to occur; neither Venus nor Mars have subduction zones. Without subduction, plate tectonics could not exist and Earth would be a very different planet. Without subduction zones, Earth's crust would not have differentiated into continents and oceans and all of the solid Earth would lie beneath a global ocean.
mafic
In geology, mafic minerals and rocks are silicate minerals, magmas, and volcanic and intrusive igneous rocks that have relatively high concentrations of the heavier elements. The term is a combination of "magnesium" and ferrum, the Latin word for iron [ma(gnesium) + f(errum) + ic] [1]. In spite of the name, mafic magmas also are rich in calcium and sodium.

Mafic minerals are usually dark in color and have a specific gravity greater than 3. Common rock-forming mafic minerals include olivine, pyroxene, amphibole, biotite and other micas, augite and the calcium-rich plagioclase feldspars. Common mafic rocks include basalt and gabbro.

Mafic lava, before cooling, has a lower viscosity than felsic lava due to its lower silica content. Water and other volatiles can more easily and gradually escape from mafic lava, so eruptions of volcanoes made of mafic lavas are less explosively violent than felsic lava eruptions. Most mafic lava volcanoes are oceanic volcanoes, like Hawaii.
felsic
Term used in geology to refer to silicate minerals, magmas, and rocks which are enriched in the lighter elements such as silica, oxygen, aluminium, sodium, and potassium. The term combines the words "feldspar" and "silica." Felsic minerals are usually light in color and have specific gravities less than 3. Common felsic minerals include quartz, biotite, muscovite, hornblende, orthoclase, and the sodium rich plagioclase feldspars. The most common felsic rock is granite. On the opposite side of rock spectrum are the iron and magnesium rich mafic and ultramafic minerals and rocks.

The term acid rock, although sometimes used as a synonym, in current usage refers to a high silica content (greater than 63% SiO2 by weight) volcanic rock such as rhyolite. The term was used more broadly in older geologic literature. It is considered archaic as the terms acidic and basic rock were based on an incorrect idea dating from the 1800's that silicic acid was the chief form of silicon occuring in rocks.
Examples of hot spot magmas are ________ and _________.
the Hawaiian islands...Iceland
hot spot
In geology, a hotspot is a location on the Earth's surface that has experienced active volcanism for a long period of time. J. Tuzo Wilson came up with the idea in 1963 that volcanic chains like the Hawaiian Islands result from the slow movement of a tectonic plate across a "fixed" hot spot deep beneath the surface of the planet. Hotspots were thought to be caused by a narrow stream of hot mantle convecting up from the mantle-core boundary called a mantle plume [1], the latest geological evidence is pointing to upper-mantle convection as a cause[2][3][4]. Their Magmas are generally mafic in composition, derived solely from the mantle, unless they rise through continental crust.

Geologists have identified some 40-50 such hotspots around the globe, with Hawaii, Réunion, Yellowstone, Galápagos, and Iceland overlying the most currently active.
Partial melting and the origin of magmas
1)mafic magmas: Partial melting of upper mantles; e.g. at divergent spreading centers.

2)Intermediate Magmas: Partial melting of sedimentary rocks and mafic lithosphere; e.g. in subduction zones.

3) felsic magmas: partial melting of continental crustal rocks.
Plutons
large igneous bodies formed at depth in the earth's crust.
batholith
Massive, discordant intrusive body covering at least 100 km2.
Stock
massive, discordant intrusive body covering less than km2
Dike
Tabular, discordant intrusive body.
Sill
tabular concordant intrusive body.
mantle plume
An upwelling of anomalously hot rock in the Earth's (or another planet's) mantle. Mantle plumes are thought to be the cause of volcanic centers known as hotspots and probably also have caused flood basalts.
The process of weathering consists of...
Physical and chemical changes that occur in sediments and rocks exposed to the atmosphere and biosphere.

Results in disintegration of rocks into particles and dissolved matter.
bedrock
Bedrock is the native consolidated (unaltered) rock underlying the Earth's surface. Above the bedrock is usually an area of broken and weathered unconsolidated rock in the basal subsoil. The term implies that the rock lies in beds, or strata. Under any given location on the surface of the planet, rock will be found.
Regolith
A layer of loose, heterogeneous material covering solid rock.
Soil
A layer of altered mineral material usually mixed with organic material.
Erosion
The displacement of solids (soil, mud, rock, and other particles) by the agents of wind, water, ice, movement in response to gravity, or living organisms (in the case of bioerosion). Although the processes may be simultaneous, erosion is to be distinguished from weathering, which is the decomposition of rock. Erosion is an important natural process, but in many places it is increased by human land use. Some of those poor land use practices include deforestation, overgrazing and road or trail building. However, improved land use practices can limit erosion using techniques like terrace-building and tree planting.
Chemical weathering
A type of weathering where rocks are broken down as their minerals are dissolved and/or converted to new minerals by water and acids.
Physical weathering
A type of weathering where rocks are physically broken into smaller peices by roots, frost, aqbrasion and other processes.
CaCO₃
calcite
CaCO₃ polymorph
aragonite
CaMg(CO₃)₂
Dolomite
Fe₂O₃
hematite
Fe₃O₄
Magnetite
TiOâ‚‚
Rutile
FeSâ‚‚
Pyrite
PbS
Galena
ZnS
Sphalerite
CuFeSâ‚‚
Chalcopyrite
CaSOâ‚„
Anhydrite
CaSO₄•2H₂O
Gypsum
Examples of mafic rocks are...
Gabbro and Basalt
Examples of felsic rocks are...
Granite and Rhyolite
Examples of intermediate rocks are...
grandiorite, dacite, diorite, andesite
Porphyritic tecture occurs when...
large phenocrysts of amphibole form early, durin slow cooling, and and a fine groundmass of feldspar and glass solidify rapidly during eruption.
The mantle is low in _________, but the continental crust is high in it.
Silica
Chemical weathering of silicates
Quartz: very stable, forms sand on many beaches.

Feldspars: form clay minerals, which are stable.

Mafic: decompose to oxides and clays.
NaCl
Halite
Carbonate minerals such as _________ weather much quicker than silicate minerals such as _________.
calcite(limestone)...granite
Mechanical (or physical) Weathering
Frost wedging: water expands by 9% when it freezes.

Thermal expansion: differntial thermal expansion of minerals creates stress in rocks.

Organic activity: tree roots to micro-organisms

Mechanical abrasion: things go bump
Types of sedimentary rocks
Clastic: Composed of discrete fragments or clasts of materials derived from other rocks. They are composed largely of quartz with other common minerals including feldspars, amphiboles, clay minerals, and sometimes more exotic igneous and metamorphic minerals.

Chemical: accumulation of minerals precipitated from solution by either organic or inorganic processes. (e.g. halite)
Sedimentary Stages of Rock Cycle
⬢Weathering
⬢Erosion
⬢Transportation
⬢Deposition (sedimentation)
⬢burial
⬢diagenesis
water expands by __% when it freezes.
9%
Transportation and deposition of Clastic sedimens occurs through...
movement of sediment by wind, ice or water. A modes of transport will create distinctive deposits.
sorting
The variation in the range of grain-size of a rock or a sediment. Well-sorted sediments have a narrow range of particle-sizes, and have been subject to prolonged water and wind action. Poorly-sorted sediments have a wide range of particle sizes and are either not far removed from their source or deposited by glaciers.
roundness
measure of the angularity of particles; the less angular, the more roundness it is said to possess.
sphericity
how circular or round a particle is.
The layering that produces sedimentary structures is due to:
⬢Variations in particles size, due largely to changes in the velocity of the depositional medium.

⬢The types of particles being deposited
Examples of sedimentary structures:
⬢Cross beds
⬢Ripple marks
⬢Mudcracks
⬢Raindrop impressions
⬢Fossils (some may have been preserved in growth position)
lithification
The process whereby sediments compact under pressure, expel connate fluids (compaction), and gradually become solid rock. Essentially, lithification is a process of porosity destruction through compaction and cementation. Lithification includes all the processes which convert unconsolidated sediments into sedimentary rocks. Petrification, though often used as a synonym, is more specifically used to describe the replacement of organic material by minerals in the formation of fossils.
Cementation
The process of deposition of dissolved mineral components in the interstices of sediments. It is an important factor in the consolidation of coarse-grained clastic sedimentary rocks such as sandstones, conglomerates, or breccias during diagenesis or lithification. Cementing materials may include silica, carbonates, iron oxides, or clay minerals.

Cementation is also continually going on in the ground water zone, so much so that the term "zone of cementation" is sometimes used interchangeably. Cementation occurs in fissures or other openings of existing rocks and is a dynamic process more or less in equilibrium with a dissolution or dissolving process.
Recrystalization
geological process whereby new rock is created from sediment due to increases in pressure and temparature (both increase as more and more new sediment builds on top of older sediment).
neomorphism
a type of metamorphism in which new minerals are produced by using chemical elements present in the original minerals.
metasomatism
The chemical alteration of a rock by hydrothermal fluids. It is also known as "alteration".

Metasomatism can occur via the action of hydrothermal fluids from an igneous or metamorphic source.

In the igneous environment, metasomatism creates skarns, greisen, and may affect hornfels in the contact metamorphic aureole adjacent to an intrusive rock mass.
Major Classes of Clastic Sediments
Conglomerate-(Sed.)gravel; boulder, cobble, pebble(coarse)

Sandstone-(Sed.)sand(Medium)

Siltstone-(Sed.)mud, silt(Fine)

Mudstone, shale, Claystone-(Sed.)clay(Finer than)
__% of sedimentary rock is made up of siltstone, mudstone, and shale; sandstone and conglomerate make up __%, and Carbonate rocks __%.
75%...11%...14%
SiOâ‚‚
chert
prograde/retrograde metamorphism
Prograde refers to mineral changes that take place during a decrease in temperature.

Retrograde: mineral changes that take place during a decrease in temperature.
high/low grade metamorphism
refer to the intensity of temperatures involved in metamorphicism.
regional metamorphism
Widespread changes in temperature and pressure bring about changes in rocks due to tectonic forces.
contact metamorphism
Intrusion of magma against colder rocks. Affected area is proportional to the size and temperature of the intrusion, but always only a local phenomenon.
Common metamorphic minerals include...
amphiboles, garnet, mica, stauralite, and kyanite.
Changes in texture due to metamorphism may include...
⬢Grain size can increase or decrease

⬢Shape of grains can change

⬢Orientation/arrangements of mineral shifts
Folds and Faults are...
geologic structures caused by deformation.
Structural geology
The study of deformation of rocks and its effects.
Strength
The ability of an object to resist deformation.
brittle-ductile transition zone
A zone at an approximate depth of 10 km in the Earth, at which rock becomes less likely to fracture, and more likely to deform ductilely. In glacial ice this zone is at approximately 30 metres depth. It is not impossible for material above a brittle-ductile transition zone to deform ductilely, nor for material below to deform brittly. The zone exists because as depth increases, confining pressure increases, and brittle strength increases with confining pressure but ductile strength remains constant. The transition zone occurs at the point where brittle strength exceeds ductile strength.
competent/incompetent rocks
Competent rocks are those rocks that deform only under great stress. Incompetent rocks are those deform under moderate to low stress.
Types of Faults
⬢Normal (dip-slip)
⬢Reverse (dip-slip)
⬢Strike slip-faults
⬢Oblique-slip faults
⬢Joints (fractures with no displacement)
Strike-slip faults occur when...
the motion of the fault blocks is parallel to the strike direction.
syncline
a sequence of folded rocks with the youngest rocks on the inside of the fold.
anticline
a sequence of folded rocks with the oldest rocks on the inside of the fold.
continental drift
The concept of continental drift was first proposed by Alfred Wegener. In 1912 he noticed that the shapes of continents on either side of the Atlantic Ocean seem to fit together (for example, Africa and South America). Evidence for continental drift is now more extensive, in the form of plant and animal fossils of the same age found around different continent shores, suggesting that these shores were once joined.
evidence leading to the discovery of plate tectonics
⬢Some continents appear to have once fitted together.
⬢Identical fossil species now exist in areas now far apart.
⬢Evidence of widespread glaciation in areas now far from the poles.
⬢magnetic patterns on the sea floor.
⬢Global patterns of earthquakes and volcanic activity.
Vine-Matthews-Morley Hypothesis holds that...
⬢Mid-ocean ridges are spreading boundaries where new seafloor is created. The earth's outer layer is a mosaic of mobile "plates".
The hypothesis was initially greeted with hostility, but further investigation showed that the theory was viable.
the unifying concept of the Earth sciences bis that...
The outer portion of the earth is made up of about 20 distinct "plates" (~100 km thick), which move relative each other. This motion causes earthquakes and makes mountain ranges.
lithosphere
the solid outermost shell of a rocky planet. On the Earth, the lithosphere includes the crust and the uppermost layer of the mantle (the upper mantle or lower lithosphere) which is joined to the crust. The lithosphere is broken into giant plates that fit around the globe like puzzle pieces. These puzzle pieces move a little bit each year as they slide on top of a somewhat fluid part of the mantle called the asthenosphere.
Tectonic plates may interact at their edges by...
moving away from each other (divergent), toward each other (convergent), and sliding past each other (transform).
Mining Methods
⬢Surface Mining
-Open pit
-Strip Mining
-Contour mining

⬢Subsurface Mining
-Vein stoping
-Room and pillar
-Solution mining

⬢Ore processing
Surface mining accounts for __% of the world's mineral production.
67%
Surface mining is economical when...
⬢Ore body is near the surface, requiring removal of minimal overburden.

⬢Large tonnages of reserves available.
Mine Types
⬢Bench and highwall-for deep pits

⬢strip mining-for flat lying rocks just beneath the surface.
La Coipa gold mine is located in _____.
Chile
Cortez Gold Mines is located in _____________.
Crescent Valley, Nevada
Contour Mining
The Contour or Bench method of surface or strip mining is usually associated with coal, where a seam or multiple seams are located at a certain elevation or elevations through a mountain or hill.
Contour mining allows for the extraction of coal from mountainous areas, where it is not feasible to extract the entire seam, using mountain top removal mining. Contour mining allows for the partial removal of the coal seam at the elevation of the coal seam. Quite often, contour mining is utilized in more than one location on the same mountain.
subsurface mining methods
⬢Vein stoping--orebody is steeply tilted

⬢Room and pillar--orebody is nearly horizontal, but to deep for strip mining.

⬢Block caving--orebody is irregular or massive.
solution mining
Used largely for mining salt or halite. Once the deposit is located, fresh and recycled water is injected through a well (or wells) drilled into an underground salt bed or salt dome, usually between 150 and 1,500 meters (500 to 5000 feet) deep. Dissolution of the salt forms a void or cavern in the salt deposit. Salt brine is withdrawn from the cavern and transported by pipeline to an onsite evaporating plant to make dry salt, or to a chemical processing plant for chlor-alkali or other chemical production. Solution mines located at the site of chemical plants are called captive brine wells.
After extraction, ore is processed by...
⬢Crushing

⬢Washing

⬢Mineral separation

-Floatation
-Froth floatation
-magnetism
-Leaching
what is an ore?
A volume of earth material that can be mined at a profit.
Factors that might influence the value of a mineral deposit.
⬢Grade, % of x in an ore.
⬢Depth
⬢minerology (type of mineral, grain size)
⬢Location (determines transport costs)
The cheapest transport by far is by _______.
water
Bingham Porphyry Copper Mine
Utah
stope
An excavation in the form of steps made by the mining of ore from steeply inclined or vertical veins.
Us Oil production reached its peak during ____________.
the early seventies
A third of the total enery budget in the U.S. goes toward electricity, roughly half of which goes into...
running air conditioners.
Energy rich matter can be kept from decaying by being cut off from ________.
oxygen
Oil tends to be trapped in rock younger than ___________ years, whereas coal tends to be found in older rock.
200 million years, this is largely do to migration.
Hubbert peak theory
also known as "peak oil", concerns the long-term rate of conventional petroleum and other fossil fuel extraction and depletion. It is named after American geophysicist Marion King Hubbert, who created a model of known reserves, and proposed, in 1956, in a paper he presented [1] at a meeting of the American Petroleum Institute, that oil production in the continental United States would peak between 1965 and 1970; and that world production would peak in 2000.
The continents floated up from the mantle because...
they consisted of light and buoyant magmas; the oceanic crust is made out of less buoyant stuff.
The ocean floors are relatively young, _________ years, compared with the continental crust.
180 million
heavy elements such as iron, aluminum, and oxygen are produced in _________.
supernovas
generally, the blacker a mineral the more ______ it has.
iron
The formation of Coral atolls involves what steps?
⬢Stage 1: a volcano rises from the ocean floor.
⬢the volcano becomes extinct and erodes.
⬢A fringing reef forms.
⬢As subsidence continues, the reef completely covers the volcanic island.
Reef growth is promoted by ________, ________, and _______
waters.
shallow, clear, and warm
Gypsum is___% evaporation.

Halite is ___% evaporation.
50%

90%
Which puts out more radioactivity: coal plants or nuclear plants.
coal plants
The ____________ United States has the highest content of sulfur in the air, thus greater amounts of acid rain. This of course has detrimental affect on agricultural productivity, as well as on animal life (e.g. fish).
North-Eastern
_________ can be used to neutralize lakes with high acidity as a result of acid rain.
Limestone
__% of US energy comes from fossil fuels.
80%

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