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A Layered Sphere 3 major concentric
zones
Crust, Mantle, & Core
CRUSTCRUST = 1) continental crust & 2) oceanic crust (8
elements make up ~99% of the earth’s crust
MANTLEMANTLE = largest zone; solid; rich in iron (abundant)
CORECORE = inner core (solid) & outer core (liquid); made
mostly of iron
INTERNAL & EXTERNAL EARTH PROCESSESGeologic changes originating from the earth’s
interior are called internal processes – that build the earth’s surface
Two main types of movement occur in the asthenosphere:
1) Convection cells – large volumes of heated rock
moving in a pattern
2) Mantle plumes – rock flows upward as if in a column and
then radiates outward
Tectonic Processes
Plates (100km thick) are composed of the crust and (100km thick) are composed of the crust and the outermost part of the mantle (top of the the outermost part of the mantle (top of the
asthenosphere) known as the ) known as the lithosphere. Plates move approximately 2-15cm/year.
Spreading Subduction Lateral Sliding
Constructive (sea floor spreading)
Destructive (subduction zones)
Conservative
Ridges/Rifts Trenches No major impact
Yes Yes No
Ridges/Rifts VolcanoesTrench
Earthquakes
GEOLOGIC HAZARDS
Earthquakes - Sudden movements of the earth’s crust that occur along faults where one rock mass slides past another. (Transform Fault Boundary)
Gradual movement - creep.• When friction prevents creep, stress builds up until
eventually released with a sudden jerk. Frequently occur along subduction zones Tsunami - Seismic sea swells.
Volcanoes
Volcanoes and undersea magma vents are the sources of most of the earth’s crust.
Many of world’s fertile soils are weathered volcanic material.
• Human / Environmental Dangers
Volcanic AshMudslidesSulfur Emissions
HAWIIAN VOLCANO SYSTEM
MT. ST. HELENS
Pangea
Geologists suggest that several times in earth’s history most, or all, of the continents gathered to form a single super-continent, Pangea, surrounded by a single global ocean.
Fig. 15-4a, p. 338
EURASIAN PLATEEURASIAN PLATENORTH NORTH
AMERICAN AMERICAN PLATEPLATE
ANATOLIAN ANATOLIAN PLATEPLATE
JUAN DE JUAN DE FUCA PLATEFUCA PLATE
CHINA CHINA SUBPLATESUBPLATE
CARIBBEAN CARIBBEAN PLATEPLATE
PHILIPPINPHILIPPINE PLATEE PLATE
ARABIAN ARABIAN PLATEPLATEAFRICAAFRICA
N PLATEN PLATEPACIFIPACIFI
C C PLATEPLATE
SOUTH SOUTH AMERICAN AMERICAN
PLATEPLATENAZCNAZCA A
PLATEPLATE
INDIA-INDIA-AUSTRALIAAUSTRALIA
N PLATEN PLATE
SOMALIASOMALIAN N
SUBPLATESUBPLATE
ANTARCTIC PLATEANTARCTIC PLATE
Divergent plate boundaries
Convergent plate boundaries
Transform faults
Plate Activity….helps?
Recycle: Rock Cycle
Primary and Secondary Successsion
Minerals-distribution and creation
Divergent Evolution
ROCKS AND MINERALS
A mineral is a naturally occurring, inorganic, solid element or compound with a definite chemical composition and regular internal crystal structure.A rock is a solid, cohesive, aggregate of one or more minerals.
Each rock has a characteristic mixture of minerals, grain sizes, and ways in which the grains are held together.
Minerals
Most nonrenewable
Single Elements (Au, Ag, C) Compounds (SiO2, NaCl)
Fossil Fuels-Coal, oil, natural gas
Metallic minerals
Nonmetallic- (sand/quartz)
Rock Types
Rock Cycle - Cycle of creation, destruction, and metamorphosis.
Three major rock classifications:• Igneous
• Sedimentary
• Metamorphic
Fig. 15-8, p. 343
Erosion
Transportation
Weathering
Deposition
Igneous rock Granite,
pumice, basaltSedimentary
rock Sandstone, limestone
Heat, pressure
Cooling
Heat, pressure, stress
Magma (molten rock)
Melting
Metamorphic rock Slate, marble,
gneiss, quartzite
Weathering
Mechanical - Physical break-up of rocks into smaller particles without a change in chemical composition.
Chemical - Selective removal or alteration of specific components that leads to weakening and disintegration of rock.
Oxidation
Sedimentation - Deposition of loosened material.
Fig. 15-6, p. 340
Parent material (rock)
Biological weathering (tree
roots and lichens)
Chemical weathering
(water, acids, and gases)
Physical weathering (wind, rain, thermal
expansion and contraction, water
freezing)
Particles of parent material
Sedimentary Rock
Deposited materials that remain in place long enough, or are covered with enough material for compaction, may again become rock.
Formed from crystals that precipitate out of, or grow from, a solution.• Shale• Dolomite• Sandstone• Limestone (calcium carbonate)
Metamorphic Rock
Pre-existing rocks modified by heat, pressure, and chemical agents.
Chemical reactions can alter both the composition and structure of rocks as they are metamorphosed.• Marble (from limestone)• Quartzite (from sandstone)• Slate (from mudstone and shale)
Igneous Rocks
Most common type of rock in earth’s crust.Solidified from magma extruded onto the surface from volcanic vents.
• Quick cooling of magma produces fine-grained rocks.
Basalt• Slow cooling of magma produces coarse-grained
rocks.
Granite
Mining
1.) Surface Mining: 90% nonfuel, 60% coal
-open pit
-strip mining: contour/mountian top removal-Clean Water Act
Surface Mining Control and
Reclamation Act 1977
2.)Subsurface Mining
Higher grade orelower grade
Subsidence
¾ of solid wastes=MINING
Fig. 15-13, p. 346
Undisturbed land
Overburden
Highwall Coal seam Overburden Pit
Bench
Coal seam
Spoil banks
Fig. 15-9, p. 344
Surface mining
Metal ore Separation of ore from
gangue
Smelting Melting metal
Conversion to product
Discarding of product
(scattered in environment)
Recycling
Fig. 15-10, p. 344
Natural Capital Degradation
Extracting, Processing, and Using Nonrenewable Mineral and Energy Resources
StepsSteps Environmental effectsEnvironmental effects
Mining Disturbed land; mining accidents; health hazards,
mine waste dumping, oil spills and blowouts; noise; ugliness;
heat
Exploration, extraction
Processing
Solid wastes; radioactive material; air, water, and soil pollution; noise; safety and health hazards; ugliness;
heat
Transportation, purification,
manufacturing
Use
Noise; ugliness; thermal water pollution; pollution of
air, water, and soil; solid and radioactive wastes;
safety and health hazards; heat
Transportation or transmission to individual user,
eventual use, and discarding
Fig. 15-16, p. 348
A Mine, use, throw away; no new discoveries; rising
prices
Recycle; increase reserves by improved mining technology,
higher prices, and new discoveriesB
Pro
duct
ion
Recycle, reuse, reduce consumption; increase reserves by improved
mining technology, higher prices, and new
discoveriesC
Present Depletion time A
Depletion time B
Depletion time C
Time
Getting More Minerals from the Ocean
Hydrothermal deposits form when mineral-rich superheated water shoots out of vents in solidified magma on the ocean floor.
Figure 15-17Figure 15-17
Fig. 15-18, p. 351
Solutions
Sustainable Use of Nonrenewable Minerals
• Do not waste mineral resources.
• Recycle and reuse 60–80% of mineral resources.
• Include the harmful environmental costs of mining and processing minerals in the prices of items (full-
cost pricing).
• Reduce subsidies for mining mineral resources.
• Increase subsidies for recycling, reuse, and finding less environmentally harmful substitutes.
• Redesign manufacturing processes to use less mineral resources and to produce less pollution and waste.
• Have the mineral-based wastes of one manufacturing process become the raw materials for other processes.
• Sell services instead of things.
• Slow population growth.
SOIL LAYERSSoil is formed by the weathering of rocksweathering of rocks,
deposition of sedimentsediment by erosion, and decompositiondecomposition of organic material by
microorganisms
Leaf litter layer – leaves, animal waste, insects & decomposers; typically dark brown or black in
color (organic content)Topsoil – humus (decomposed
organic matter; porous; inorganic minerals; root systems; insects &
decomposersSubsoil – inorganic matter;
broken down rock mixture of sand, silt, clay, and gravel
Parent material – baseline beginning of the bedrock that lies
below
Water Water
High permeability Low permeability
Fig. 10.17, p. 224
100%clay100%clay
IncreasingIncreasingpercentage siltpercentage silt
IncreasingIncreasingpercentage claypercentage clay
00
2020
4040
6060
8080
8080
6060
4040
2020
00100%sand100%sand 8080 6060 4040 2020 100%silt100%silt
Increasing percentage sandIncreasing percentage sand
Infiltration – downward movement of water through
soil (percolation)
Leaching – as water seeps down it dissolves soil
components (nutrients) in upper layers & carries it to
lower layersSoil texture determines porosity and permeability
Loam – roughly equal mixtures of
clay, sand, silt, and humus (best soil for growing most
crops)
Texture Nutrient Infiltration Water-Holding Aeration TilthCapacity Capacity
Clay Good Poor Good Poor Poor
Silt Medium Medium Medium Medium Medium
Sand Poor Good Poor Good Good
Loam Medium Medium Medium Medium Medium
PROPERTIES OF SOILS
pH of the soil impacts the ability of nutrients by plantsIf soil is too acidic lime is sometimes but it accelerates decomposition of
organic matter so more organic fertilizer will also be used to maintain fertility
In arid regions that have alkaline soils sulfur may be added which will slowly be converted to sulfuric acid by bacteria