Chapter 12 Mineral and Soil Resources

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Chapter 12 Mineral and Soil Resources
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Copper Basin, Tennessee

• 19th century
• Copper mining
• Open-air smelters
• Trees cut to provide wood for smelters
• Sulfur dioxide formed -? acid precipitation
• Ecological ruin

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Copper Basin, Tennessee

• 1970s replanting techniques
• Plants had to be reestablished why?
• Area improving
• Return of forest
• will take decades

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Basic Geology

• Lithosphere
• Earths outermost layer
• Seven large plates
• Floats on asthenosphere
• The plates move
• plate tectonics

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Plate Tectonics

• Plate boundary
• Where two plates meet
• Intense geologic activity
• Earthquakes, volcanoes
• Formation of mountains
• Atlantic Ocean growing separating plates

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Plates Boundaries
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Plate Boundaries
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Volcanoes

• Movement of tectonic plates on hot
• soft rock
• Heat melts rock ? magma
• Lava magma
• at surface
• Environmental
• impacts of
• eruptions?

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Earthquakes

• Rocks in lithosphere shift or break
• Energy released as seismic waves
• Usually along fault
• Focus where quake begins
• Epicenter directly above focus
• More than 1 million quakes per year
• Measure using Richter scale

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Side Effects of Earthquakes

• Landslides
• Tsunamis
• Giant sea waves
• Indian Ocean 2004
• Waves over 30 m
• More than 225,000 died

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Rock Cycle

• Aggregates of one or more minerals
• Based on rock formation
• Igneous rock
• Metamorphic rock
• Sedimentary rock

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Important Minerals

• Sulfides contain sulfur
• Oxides contain oxygen
• Metals
• Malleable, lustrous, conductors
• Iron, aluminum, copper
• Nonmetallic minerals
• Ore
• Rock with valuable mineral

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Minerals Their Uses
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Extracting Minerals

• Locate deposit
• Analyze mineral composition
• Mine for minerals many different ways
• Process mineral
• Make product

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Surface Mining

• Near the surface
• Less expensive
• Overburden removed
• Open-pit
• Dig quarry
• Iron, copper, gravel

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Surface Mining

• Strip mining
• Dig trench to extract mineral
• Dig parallel trench
• Cover old trench with new overburden
• Spoil bank

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Subsurface Mining

• Minerals deep in ground
• Less land disturbance
• More expensive
• More hazardous
• Shaft mine
• Direct
• vertical shaft
• Coal

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Subsurface Mining

• Slope mine
• Slanting passage
• Ore hauled in cars

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Processing Minerals

• Smelting
• Melt ore to separate impurities from desired
  mineral
• Blast furnace
• Slag disposed of

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Mining The Environment

• Disturbs land
• Land prone to erosion ? further damage
• Uses a lot of water
• Contaminated streams
• Acid-mine drainage

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Impacts of Refining

• About 80 of mined ore made of impurities
• Tailings
• Waste left
• behind
• Left in piles
• Toxic

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Impacts of Refining

• Smelting emits pollutants
• Acid precipitation
• Hazardous solid and liquid wastes
• A lot of energy required

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Restoration of Mining Lands

• When mine no longer profitable
• Prevents further degradation
• Filling in and grading the area
• Planting vegetation
• Surface Mining Control
• Reclamation Act of
• 1977
• Lands mined for coal

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Soil What Is It?

• More than just dirt!
• Uppermost layer of Earths crust
• Mineral and organic matter
• Living organisms
• We depend on it how?

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Soil Formation

• Formed from parent material
• Biological, chemical and physical weathering
  processes
• Continuous process
• Topography plays a role how?
• Takes a long time

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Soil Composition

• Four main parts
• Mineral particles
• Main component
• From parent material
• Provides anchorage and minerals
• Organic matter
• Living or formerly living matter
• Humus
• Air
• Water

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Soil Profile

• Look at horizons layers
• O horizon surface layer
• A horizon topsoil
• Deep in grassland soils
• Thinner in forest, tropical soils
• B horizon subsoil
• C horizon parent material
• Materials leach through the layers

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Soil Profile
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Soil Organisms

• Soil is alive!
• Plant roots, insects, earthworms, moles, etc
• Bacteria most numerous
• Fungi, algae, protozoa
• Provide ecosystem services examples?

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Soil Organisms
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Decomposition

• Nutrient cycling
• Pathway of nutrient minerals or elements
• Sign of balanced ecosystem

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Soil Problems

• Our activities cause many problems
• Soil erosion
• Mineral depletion
• Soil pollution
• Sustainable soil use
• Wise use of soil resources
• Keep soil productive for the future

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Soil Erosion

• Movement of soil
• Natural process
• Accelerated today
• Water, wind
• Major effects
• Loss of soil
• fertility
• Soil cannot retain as much water
• Runoff into bodies of water

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Soil Erosion

• Poor soil management
• Agriculture, road
• building, logging
• Plant cover limits
• erosion

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Soil Pollution

• Physical or chemical change in soil
• Adversely affects health of organisms
• Some from fertilizers, pesticides
• Salinization
• Result of irrigation
• Can render soil
• useless

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Soil Conservation

• Only 11 worlds soil suitable for agriculture
• Much already degraded

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Conservation Tillage

• Residues from previous crops left in soil
• Reduces erosion up to 70
• More than 1/3 U.S. cropland
• Soil has more organic material
• Drawbacks?

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Crop Rotation

• Planting a series crops in the same field over a
  period of years
• Decreases insect damage
• Reduces erosion
• Rotated crops depend
• on where you farm

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Terracing

• Used on very steep slopes
• Like stairs
• Very expensive!

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Other Methods

• Contour plowing
• Farm with the natural contours of the land
• Strip cropping
• Strips of differing crops

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Soil Reclamation

• Badly eroded land
• Prevent further erosion
• Seed bare ground
• Plant shelterbelts
• Restore soil fertility
• Soil must recover first
• Restrict farming?

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U.S. Soil Conservation Policies

• Food Security Act of 1985
• Farm Bill
• Conservation compliance
• Highly erodible land
• Must have 5 year conservation plan
• Lose federal subsidies

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U.S. Soil Conservation Policies

• Food Security Act of 1985
• Conservation Reserve Program (CRP)
• Voluntary program
• Take land out of production for 1015 years
• Receive subsidy
• Reduced soil erosion
• Wildlife habitat

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Case Study Industrial Ecosystems

• Industrial ecology
• Efficient use of resources
• Wastes are potential products
• Mimic natural ecosystems
• Kalundborg, Denmark
• Link different industries

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Kalundborg, Denmark
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Case Study Industrial Ecosystems

• Takes many years to develop
• Economy and environment benefit how?