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Coombs - APES Chapter 15

study of dynamic processes that occur on earth's surface and interior
most interior portion of the earth; extremely hot; solid inner core surrounded by liquid core of molten or semisolid material
surrounds core but underneath the crust; mostly solid rock upper part but under this is the athenosphere made of melted, pliable rock that flows
part of mantle made of melted rock; lies under solid rock portion of the mantle (closest to the core)
outmost and thinnest zone of the earth
Continental Crust
area of crust that is under land mass or continents as well as continental shelf of oceans
Oceanic Crust
area of crust that is under oceans; makes approximately 71% of earth's surface
Convection Cells
large volumes of rock material move in loops (hot goes up and forms new crust and gets pushed to side; cool moves across surface of earth and eventually back down to be reheated and remelted); causes plate tectonic movements
Tectonic Plates
dozen or so huge plates of crust move across surface of earth due to heating and cooling associated with Convection Cells
molten rock; material that tectonic plates "float" on and move along due to Convection Cells
solid earth composed of crust and solid rock portion of the upper mantle (above the athenosphere)
Convergent Plate Boundary
two tectonic plates come together; can cause subduction - continental plate rides over and pushes oceanic plate down; also can cause mountain bulding when two continental plates collide and push each other up toward sky; creates mountains
specific example of convergent plate boundary where more dense ocean plate is runs into less dense continental plate and the ocean plate is pushed back down into mantle
Subduction Zone
area where subduction takes place
occurs when two ocean plates converge
Divergent Plate Boundary
oceanic plates move away from one another; usually creates oceanic ridges from molten rock (magma) that flows up from the resulting cracks
Oceanic Ridges
created from divergent plate boundaries of oceanic plates; creates higher peaks and deeper canyons than the tallest mountains found on earth's surface
Tranform Fault
plates slide and grind past each other along a fracture or fault; ex: San Andreas Fault; usually cause earthquakes and volcanoes
External Processes
geologic changes based directly or indirectly on energy from sun or gravity (instead of heat in the earth's interior); ex: weathering, erosion, storm events, flooding, etc.
Internal Processes
geologic changes based directly or indirectly on heat from earth's interior; ex: volcanism, earthquakes, plate tectonics, etc.
physical, chemical, biological processes that break down rocks and minerals into smaller particles and help build soil
Physical / Mechanical Weathering
large rock material, soil, or minerals are broken into smaller pieces
Frost Wedging
type of physical / mechanical weathering; water collects in spaces of rock, expands as it freezes, and breaks pieces of the rock off into smaller pieces
Chemical Weathering
chemical reactions "decompose" rocks, minerals, soil; oxygen, carbon dioxide, and moisture usually play a role; process accelerated by high moisture and high temperatures
Biological Weathering
conversion of rock, minerals, soil into smaller pieces by actions of living organisms; ex: lichens living on rocks produce chemicals that weather the rock; ex: roots growing into and rubbing agains rocks can break them into smaller pieces
process where material is dissolved, loosened, or worn away from one part of the earth's surface and deposited elsewhere
slow flowing bodies of ice
Mass Wasting
rock and soil mass becomes detached from underlying material and move downhill due to gravity; ex: mudslides, avalanche, rockslides, mud flows, etc.
element or inorganic compound that occurs naturally and is solid with a regular internal crystalline structure; ex: gold, silver, salt, quartz
Mineral Resource
concentration of naturally occuring material in or on earth's crust that can be extracted and processed into useful materials at an affordable cost
Fossil Fuels
type of mineral resource; ex: coal, oil, natural gas
Metallic Minerals
type of mineral resource; ex: aluminum, iron, copper
Nonmetallic minerals
type of mineral resource; ex: sand, gravel, limestone
Identified Resources
deposits of nonrenewable mineral resource with a known location, quantity, or quality and existence is based on geologic evidence and measurement
Undiscovered Resources
potential supply of mineral resource assumed to exist based on geologic knowledge and theory but unknown specific locations, quality, and amounts
identified resources from which a usable nonrenewable mineral can be extracted profitably at current prices
Other Resources
undiscovered resources and identified resources not classified as reserves
solid combination of one or more minerals that is part of earth's crust
rock that contains large concentration of a particular mineral (often metal) and can be mined to extract the desired mineral
High-Grade Ore
rock that contains fairly large amount of desired mineral
Low-Grade Ore
rock that contains smaller amounts of desired mineral
Igneous Rock
forms below or on earth's surface when molten rock (magma) wells up from the earth's upper mantle or deep crust then cools and hardens; ex granite, lava rock
Sedimentary Rock
forms from sediment produced when existing rocks are weathered and eroded into small pieces, transported by water, wind or gravity downstream, downwind, or downhill; layers deposited over time are compressed and form new rock; ex: sandstone, shale, dolomite, limestone
Metamorphic Rock
forms when preexisting rock is exposed to high temperatures, high pressure, chemically active fluids, or a combination of these; ex: coal, slate, marble
the percent metal content of an ore
Surface Mining
method used to extract surface deposits or shallow deposits of minerals; ex: open pit, strip, mountain top removal
Subsurface Mining
method used to extract deep deposits of minerals
soil and rock that cover the valuable mineral / ore to be extracted during surface mining
discarded waste material that is heaped up from overburden that has been removed during surface mining
Open-Pit Mining
type of surface mining where expansive holes are dug down, each hole smaller than the next so as to "terrace" the surface mine
Strip Mining
type of surface mining useful for removing mineral deposits that lie close to surface in large horizontal beds
Area Strip Mining
type of surface mining used when terrain is fairly flat
Spoils Banks
highly erodible hills of rubble and mining waste; often susceptible to weathering and erosion by wind and water
Contour Strip Mining
type of surface mining used on hilly or moutainous terrain; series of terraces cut into side of hill
wall of dirt left in front of highly erodible bank of soil and rock after contour strip mining takes place
Mountaintop Removal
type of surface mining where explosives, tall power shovels (20 stories high) move top of mountains off to extract coal; waste rock and dirt often dumped into streams and valleys below leading to flooding problems and toxic waste water
Surface Mining Control and Reclamaation Act of 1977
requires mining companies to restore (reclaim) most surface-mined land by grading and replanting it
replacing disturbed land that has been surface-mined by grading and replanting the area
settling and sometimes collapse of land that is above an underground mine
Acid Mine Drainage
when rainwater seeping through min or mine wastes carries sulfuric acid (a waste product from bacteria respiring aerobically using iron sulfide minerals found in spoils) to nearby streams and groundwater
Ore Minerals
valuable metals part of ore that needs to be extracted from the gangue
waste material found with ore that needs to be removed from the ore minerals; then usually piled off to the side in piles called tailings
piles of solid waste from the gangue that was seperated from the ore mineral
roasting ore to release the valuable metals
Cyanide Heap Extraction
spraying toxic cyanide salts on huge open-air heaps of crushed ore to chemically remove valuable ore; ex: used to remove 85% of world's gold from ore
Depletion Time
how long it takes to remove a certain proportion of (usually 80%) the reserves of a mineral at a given rate of use
use naturally occuring or genetically modified microorgansisms (often bacteria) to extract a particular mineral / metal
Ecoindustrial Revolution
shift in thinking over next 50 years that will involve changing industrial processes to better mimic natural processes and ecosystems
Resource Exchange Webs
having industries interact with one another and be situated near each other so wastes of one manufacturer can become raw materials for another
abandoned industrial sites that can be rehabilitated and developed
trying to get industrial processes to mimic the natural world; ex: recycling, using wastes to create new products, reusing abandoned land