Chapter 14 Study Guide
1. Earth is a dynamic planet
 core: composed of dense, intensely hot mass of metal (mostly ron)
thousands km in diameter
 mantle: molten outer core is hot, pliable layer of rock
 less dense than core/ higher light concentrations
 crust: outermost layer of earth, lightweight brittle
2. Tectonic processes move continents
 Tectonic plates: convection currents in mantle  force to move
overlying crust, mosaic of huge blocks
 Plates slide slowly across earth surface, sometimes breaks
 Magma: molten rock forced up thru cracks form new oceanic curst that
up underwater in = mid oceanic ridges
 Ridges = 74,000 km (46,000mi)
 Continential plate usually rides up over seafloor = ocean plate subdued
or pushed down into mantle
 Plate down = heat and pressure & crystallized minerals
 Volcanoes: magma erupts thru vents & fissures in
overlying crust
 PANGEA= super continent; before continents split & moved around
3. Rocks are composed of minerals
 Mineral: naturally occurring, inorganic, solid element or compound w/
specific chem comp &crystal structure
 Rock: solid, cohesive, aggregate (form) of one or more minerals
(individual mineral crystals mixed & held tightly)
 Diff kinds of rocks = diff % of these or other minerals
4. Rocks & minerals recycled constantly
 Rock cycle: creation, destruction, and metamorphosis
 Igneous rock: earth crust, solidified magma
 Metamophic rock: extreme heat/ pressure transform mineral
structures to create new forms
 Folded, heated, squeezed, layers by tectonic process
 Often show patterns of banding/folding
 Ex) marble, quartzite, slate
5. Weathering breaks down rocks
 Sedimentary rocks: accumulations of sand, mud & other material
deposited over time from another source
 erode steadily exposed = air, water, changing temps,
reactive chemicals
 weathering: gradually breaking down of exposed rocks
o mechanical weathering (physical): physical break ups of rocks
ino smaller particles w/o changing in chem compo of constituent
minerals
o chemical weathering: selective removal/alteration of specific
components that leads to weakening & disentrigation of rock
o sedimentation: deposition of 02, h20, ice gravity
 layer accumulates millions yrs = mass compact hardens
deep layers  sand becomes sandstone & clay
 rocks grained, deposited near shore or in deep h20
 also form as salt layers
14.2 Earth resources

4,400 diff mineral species
1. Metals especially valuable resources
 Economic metals
 Iron
 Aluminum
 Manganese
Consumed in USA, Japan, Europe
 Copper
 Chromium
 Nickel
op
 Rare earth metals = key to production of small electronics, lightweight
motors, batteries for hybrid cars
 Sparsely distributed= considerable enviro disturbance
2. Fossil Fuels originated as peat and plankton
 fossil fuels: deposits from living organisms
 coal: leaves and other plant materials accumulated in ancient swamps
 oil: remains of tiny plankton & algae
o rich in delta enviro
o sand, mud, clay = oil compounds in shale or sandstone
o ex) texas & saudi Arabia = oil body fluid
3. Conserving resources saves energy & materials
 Reduce effects of mining/processing including h20 contamination,
air pollution and energy use
o Ex) aluminum = expensive- intensive energy process
o May metals can be RECYCLED
4. Resource substitution reduces demand
 Consumption reduced by sub traditionl materials w/new
 Recuse cost & weight + fuel efficiency (car substitute)
14.3 Environmental effects of resource extraction
1. Different mining tech pose diff risks to h20 & 02
 Extract geological materials
o Open pit mining
o Strip mining
o Underground mining
 Dangerous
 Ex) mine fire in Centralia, PY / been burning since 1962 =
control efforts $40 million
 Ex) china coal mine fire over 400 yrs
o Surface mining
 Surface mining control and reclamation act (1977):
required better restoration of strip mined lands
2. Processing produces acids & metals
 Metals extracted by oves by heating w/or chem solvents
o Both release large # of toxic materials = enviro hazard
o Smelting/roasting ore= major 02 pollution
 Ex) 1800’s Ducktown, TN = open wood fires to extract
copper = dense clouds of sulfur oxide
o Future increasingly liable for enviro damages
3. High value minerals can support corruption
 Valuable materials bankrolled political dictators, criminal gangs and
terrorism around world
o Although international agreements often ban trade that finances
war & genocide, illegal trade continues
o Unaware obtained thru inhumane labor & enviro destructive
mining & processing methods
 Public policy in US encourages mining on public lands as a
way of boosting economy & utilizing natural resources
14.4 Geological hazards
1. Earthquakes occur on plate margins
 Earthquakes: sudden movements in earths crusts that occur along faults
(planes of weakness) where 1 plate slides past another
o ex) 2010 haiti earthquake
o San Andres fault in CA, one of most visible faults in the world
o Vary dramatically in amount of energy & movement release
 Most deaths revolve around collapsing building
2. Tsunamis can be more damaging than earthquakes
 Tsunamis: powerful waves triggered by earthqukes/landslides
o ex) 2011, japan, 9.0 earthquake = heavy dangerous waves
 25,000 ppl dead, missing
3. Volcanoes eject gas, ash, as well as lava
 Volcanoes: (undersea magma vents) produce much of earths crust
o Threaten to human pop b/c eruption & ash
o Exceed 1,000 c & 100km/hr (60mph)
4. landslides and mass wasting can bury villages
 mass wasting: geological materials are moved downslope from on place
to another
o slow but swift, dangerous and very obvious
o building on steep unstable slopes = increase chances
5. Floods are the greatest geological hazard
 Cause damage when ppl get in its wat
o Ex) Yangtze River, 1931, killed 3.7million ppl
 Heat storage (climate change) in atmosphere= cause xtreme weather
events (droughts & intense rainfall)
 Clearing forests & destroy natural wetlands = INCREASE
VOLUME AND RATE OF H20 DISCHARGE AFTER STORM
 National flood insurance program = aid ppl w/o insurance