Chapter 16 Vocabulary Flashcards
geology
Study of the earth’s dynamic history. Geologists study and analyze rocks and the features and processes of the earth’s interior and surface
core
Inner zone of the earth. It consists of a solid inner core and a liquid outer core (3)
mantle
Zone of the earth’s interior between its core and its crust (2)
crust
Solid outer zone of the earth. It consists of oceanic crust and continental crust (1)
convection cells/currents
internal heat pushes rock upwards and down
mantle plumes
type of movement that occurs with mantle
tectonic plates
Various-sized areas of the earth’s lithosphere that move slowly around with the mantle’s flowing asthenosphere. Most earthquakes and volcanoes occur around the boundaries of these plates
lithosphere
Outer shell of the earth, composed of the crust and the rigid, outermost part of the mantle outside the asthenosphere; material found in earth’s plates
plate tectonics
Theory of geophysical processes that explains the movements of lithospheric plates and the processes that occur at their boundaries
continental drift
- concept that became widely accepted by geologists in the 1960s
- continents have split and joined as plates have very slowly drifted thousands of kilometers back and forth across the planet’s surface
divergent plate boundary
- lithospheric plate boundary
- where the plates move apart in opposite directions
convergent plate boundary
- lithospheric plate boundary
- where the plates are pushed together by internal forces.
transform fault
- lithospheric plate boundary
- occurs where plates slide and grind past one another along a fracture (fault) in the lithosphere
- most found on ocean floor, but some on land
erosion
- external process
- process by which material is dissolved, loosened, or worn away from one part of the earth’s surface and deposited elsewhere
- flowing streams cause most erosion
- wind blowing particles causes it also
weathering
physical, chemical, and biological processes that break down rocks and minerals into smaller particles that can be eroded.
physical/mechanical weathering
a large rock mass s broken into smaller fragments.
frost wedging
- most important agent of mechanical weathering
- water collects in pores and cracks of rock, expands upon freezing, and splits off pieces of the rock
chemical weathering
- one or more chemical reactions decompose a mass of rock
- most chemical weathering involves a reaction of rock material with oxygen, carbon dioxide, and moisture
biological weathering
the conversion of rock minerals into smaller particles through the action of living things
ex.) lichens produce acids that can chemically weather rocks
earthquake
shaking of the ground resulting from the fracturing and displacement of rock, which produces a fault, or from subsequent movement along the fault
Richter scale
- scientists use it
- each unit represents an amplitude 10 times greater than the next smaller unit
- measures earthquakes
aftershocks
-after a big shock that gradually decreases in frequency over a period of up to several months
foreshocks
-occur seconds or up to weeks before the main shock
tsunamis
huge water waves (tidal waves)
volcano
vent or fissure in the earth’s surface through through which magma, liquid lava, and gases are released into the environment
fissure
long crack
ejecta
debris ranging from large chunks of lava rock to ash that may be glowing hot
mineral
an element or inorganic compound that occurs naturally and is solid with regular internal crystalline structure
rock
solid combination of one or more minerals that is part of the earth’s crust
igneous rock
- formed below or on earth’s surface
- molten rock wells up and cools and hardens to form a rock
sedimentary rock
- formed from sediment produced when existing rocks are weathered and eroded into smaller pieces
- they are transferred and accumulated over time to form a rock
metamorphic rock
-produced when a preexisting rock is subjected to high temperature and a lot of pressure
rock cycle
The interaction of physical and chemical processes that changes rock from one type to another
nonrenewable mineral resource
a concentration of naturally occurring material in or on the earth’s crust that can be extracted and processed into useful materials at an affordable cost
ore
rock containing enough of one or more metallic minerals to be mined profitably
identified resources
deposits of a nonrenewable mineral resource with a known location, quantity, and quality, or whose existence is based on direct geological evidence and measurements
reserves
identified resources from which a usable nonrenewable mineral can be extracted profitably at current prices
undiscovered resources
potential supplies of a nonrenewable mineral resource assumed to exist on the basis of geological knowledge and theory but with unknown specific locations, quality, and amounts
surface mining
mining shallow deposits
subsurface mining
mining deep deposits
overburden
layer of soil and rock overlying a mineral deposit
spoils
unwanted rock and other waste materials produced when a material is removed from the earth;s surface and subsurface
open-pit mining
machines dig holes and remove ores, sand, gravel, and stone
dredging
chain buckets and draglines scrape up underwater mineral deposits
area strip mining
an earth-mover strips away the overburden, a huge power shovel digs a cut to remove the mineral deposit an then the trench is refilled
contour strip mining
- Used on hilly or mountainous terrain
- Earthmover removes overburden and coal is extracted with a power shovel
mountaintop removal
Involves explosives, massive shovels and huge machinery called draglines to remove the top of the mountain and expose the coals underneath
subsidence
slow or rapid sinking of part of the earth’s crust that is not slope-related
acid mine drainage
occurs when rainwater seeping through a mine or mine wastes carries sulfuric acid to nearby streams and groundwater
gangue
waste or undesired material in an ore
tailings
rock and other waste naturals removes as impurities when waste mineral material is separated from the metal in an ore
smelting
proces in which a desired metal is separated from the other elements in an ore mineral
depletion time
how long it takes to use up a certain portion of the reserves of a mineral at a given rate
Explain the General Mining Law of 1872. How was it modified in 1992?
- designed to encourage mineral exploration and the mining of hardrock minerals on U.S. public lands
- help develop the then sparsely populated West.
- Under this law, a person or corporation can get mining rights for hardrock minerals or assume legal ownership for parcels of land on essentially all U.S. public land, except parks and wilderness
- Modified to require mining companies to post bonds to cover 100% of the estimated cleanup costs in case they go bankrupt
Describe the two kinds of movement occurring in the mantle’s asthenosphere.
Convection cells or currents and mantle plumes
What happens when the plates collide, break apart, or slide by one another?
they produce mountains on land (such as the Himalayas and the Appalachian Mountains of the eastern U.S.), huge ridges and trenches on the ocean floor, and other features of the earth’s surface.
Describe the three types of plate boundaries.
- divergent plates
- convergent plates
- transform fault
Describe the three types of weathering processes?
physical or mechanical
chemical weathering
biologist weathering
What are the primary and secondary effects of earthquakes?
- primary effects of earthquakes include shaking and sometimes a permanent vertical or horizontal displacement of the ground
- The secondary effects include rockslides, urban fires, and flooding caused by subsidence (sinking) of land.
Where do volcanoes occur?
where magma reaches the earth’s surface through a central vent or a long crack
How do the three major types of rocks form?
igneous rock- formed below or on the earth’ surface when magma wells up from the earth’s upper mantle or deep crust, cools, and hardens
sedimentary rock- forms rom sediment produced when existing rocks are weathered and eroded into small pieces, and transported from their sources
metamorphic rock- formed when a preexisting rock is subjected to high temps, high pressures, chemically active fluids, or a combination of these agents
Explain the Surface Mining Control and Reclamation Act of 1977.
- requires mining companies to restore most surface-mined land so it can be used for he same purpose as before it was mined
- The act also levied a tax on mining companies to restore land that was disturbed by surface mining before the law was passed.
Describe the three major mining methods used to extract underground deposits.
underground coal mine- when mine shafts and tunnels are dug and blasted out
room-and-pillar - machinery is used to gouge out coal and load it onto a shuttle car in one operation, and pillars of coal are left to support the mine surface
longwall mining- movable steel props support the roof and cutting machines shear off the coal onto a conveyor belt
In what six ways can mining harm the environment?
-scarring and disrupting the land surface
-cause houses to silt
-sewer lines to crack
-gas mains to break
0groundwater systems to be disrupted
-toxin-laced mining wastes can be blown or deposited elsewhere by wind or water erosion
-acid mine drainage.
List the negative effects of removing the gangue from ores.
- produces piles of waste called tailings
- particles of toxic metals blown by the wind or leached from tailings by rainfall can contaminate water and groundwater.
Why is it necessary to have effective polllution control equipment for the smelting process?
because if we do not have them, smelters will emit enormous quantities of air pollutants, which damage vegetation and soils in the surrounding area. They would also cause water pollution and produce liquid and solid hazardous wastes that must be disposed of safely with the equipment.
Why are most mineral prices artificially low?
because governments subsidize development of their domestic mineral resources to help promote economic growth and national security.
Why have modules and resource-rich mineral beds in international waters not been developed?
- high costs
- squabbles over who owns them
- how many profits from extracting them should be disrupted among the world’s nations
asthenosphere
- outermost part of the mantle
- very hot
- made of melted rock
- deformed like soft plastic
