1. Geology and Nonrenewable Mineral Resources
Chapter 16
Geology and
Nonrenewable Mineral Resources

2. Geologic Processes Plate Tectonics
Section 16-1 & 16-2
Geologic Processes Plate Tectonics

3. GEOLOGIC PROCESSES
The earth is made up of a core, mantle, and crust and is constantly changing as a result of processes taking place on and below its surface.
The earth’s interior consists of:
Core: innermost zone with solid inner core and molten outer core that is extremely hot.
Mantle: solid rock with a rigid outer part (asthenosphere) that is melted pliable rock.
Crust: Outermost zone which underlies the continents.

4. GEOLOGIC PROCESSES
Major features of the earth’s crust and upper mantle.
Figure 15-2

5. Tectonic plate Inner core
Spreading center
Collision between two continents
Oceanic tectonic plate
Ocean trench
Oceanic tectonic plate
Plate movement
Plate movement
Tectonic plate
Oceanic crust
Oceanic crust
Subduction zone
Continental crust
Continental crust
Material cools as it reaches the outer mantle
Cold dense material falls back through mantle
Hot material rising through the mantle
Mantle convection cell
Figure 15.3
Natural capital: the earth’s crust is made up of a mosaic of huge rigid plates, called tectonic plates, which move around in response to forces in the mantle.
Mantle
Two plates move towards each other. One is subducted back into the mantle on a falling convection current.
Hot outer core
Inner core
Fig. 15-3, p. 337

6. GEOLOGIC PROCESSES
Huge volumes of heated and molten rack moving around the earth’s interior form massive solid plates that move extremely slowly across the earth’s surface.
Tectonic plates: huge rigid plates that are moved with convection cells or currents by floating on magma or molten rock.

7. The Earth’s Major Tectonic Plates
Figure 15-4

8. The Earth’s Major Tectonic Plates
The extremely slow movements of these plates cause them to form boundaries
Convergent plate boundaries grind into one another
Divergent plate boundaries plates move apart
Transform plate boundaries slide past each other
Figure 15-4

9. Boundaries
Divergent – the plates move apart in opposite directions.

10. Convergent – the plates push together by internal forces.
At most convergent plate boundaries, the oceanic lithosphere is carried downward under the island or continent.
Earthquakes are common here.
It also forms an ocean ridge or a mountain range.

12. Boundaries (Continued)
Transform – plates slide next or past each other in opposite directions along a fracture.
California will not fall into the ocean!

13. Figure 15.4
Natural capital: the earth’s major tectonic plates. The extremely slow movements of these plates cause them to grind into one another at convergent plate boundaries, move apart from one another at divergent plate boundaries, and slide past one another at transform plate boundaries. QUESTION: What plate are you floating on?
Fig. 15-4, p. 338

14. GEOLOGIC PROCESSES
The San Andreas Fault is an example of a transform fault.
Figure 15-5

15. Pacific Plate
The Pacific plate is off the coast of California. Lots of volcanoes and earthquakes occur here.
“California will fall into the ocean” idea.
It is the largest plate and the location of the ring of fire.

16. Wearing Down and Building Up the Earth’s Surface
Weathering is an external process that wears the earth’s surface down.
Figure 15-6

17. Importance
Plate movement adds new land at boundaries, produces mountains, trenches, earthquakes and volcanoes.

18. Geologic Hazards & Minerals, Rocks & The Rock Cycle
Section 16-3 & 16-4
Geologic Hazards & Minerals, Rocks & The Rock Cycle

19. MINERALS, ROCKS, AND THE ROCK CYCLE
The earth’s crust consists of solid inorganic elements and compounds called minerals that can sometimes be used as resources.
Mineral resource: is 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.

20. General Classification of Nonrenewable Mineral Resources
The U.S. Geological Survey classifies mineral resources into four major categories:
Identified: known location, quantity, and quality or existence known based on direct evidence and measurements.
Undiscovered: potential supplies that are assumed to exist.
Reserves: identified resources that can be extracted profitably.
Other: undiscovered or identified resources not classified as reserves

21. General Classification of Nonrenewable Mineral Resources
Examples are fossil fuels (coal, oil), metallic minerals (copper, iron), and nonmetallic minerals (sand, gravel).
Figure 15-7

22. Rock Cycle
The Rock Cycle – the interaction of processes that change rocks from one type to another
Rock Cycle
Figure 15-8

23. Steps

24. GEOLOGIC PROCESSES
Deposits of nonrenewable mineral resources in the earth’s crust vary in their abundance and distribution.
A very slow chemical cycle recycles three types of rock found in the earth’s crust:
Sedimentary rock (sandstone, limestone).
Metamorphic rock (slate, marble, quartzite).
Igneous rock (granite, pumice, basalt).

25. Element Abundance
Oxygen: The most abundant element in Earth’s crust
Nitrogen: The most abundant element in the Earth’s atmosphere.
Iron: The most abundant element in the Earth’s core.
Aluminum: The element commercially extracted from bauxite

26. Rock Classification Igneous Rock
Description – forms the bulk of the earth’s crust. It is the main source of many non-fuel mineral resources.
Examples – Granite, Pumice, Basalt, Diamond, Tourmaline, Garnet, Ruby, Sapphire

27. Sedimentary Rock
Description – rock formed from sediments. Most form when rocks are weathered and eroded into small pieces, transported, and deposited in a body of surface water.
Examples: sandstone (sand stuck together), Conglomerate (rounded & concrete-looking) and Breccia (like conglomerate but w/ angular pieces)

28. Metamorphic Rock
Description – when preexisting rock is subjected to high temperatures (which may cause it to partially melt), high pressures, chemically active fluids, or a combination of these
Location – deep within the earth
Ex. limestone under heat becomes marble through crystallization
Limestone -> marble
sandstone -> quartzite
shale -> hornfelds (slate)

29. Removing & Processing Non-Renewable Mineral Resources
Section 16-5
Removing & Processing Non-Renewable Mineral Resources

30. Nonrenewable Resources
Definition – things human use that have a limited supply; they cannot be regrown or replenished by man

31. Dealing with Nonrenewable Resources
Conservation
Definition – using less of a resource or reusing a resource, ex. refilling plastic laundry jugs, reusing plastic bags, etc.
Problems – this requires a change in our lifestyle and some people will resist.

32. Restoration Definition – recycling our resources
Examples – aluminum, glass, tin, steel, plastics, etc.
Problems – recycling a resource often costs more than using the raw material; we don’t have the technology to recycle everything

33. Sustainability
Definition – prediction of how long specific resources will last; ex. we have a 200 year supply of coal in the U.S.
Knowing this helps people make decisions in resource use
Problems – these are only predictions; they may not be accurate

34. Natural Capital Degradation
Extracting, Processing, and Using Nonrenewable Mineral and Energy Resources
Steps
Environmental effects
Mining
Disturbed land; mining accidents; health hazards, mine waste dumping, oil spills and blowouts; noise; ugliness; heat
Exploration, extraction
Processing
Transportation, purification, manufacturing
Solid wastes; radioactive material; air, water, and soil pollution; noise; safety and health hazards; ugliness; heat
Use
Figure 15.10
Natural capital degradation: some harmful environmental effects of extracting, processing, and using nonrenewable mineral and energy resources. The energy required to carry out each step causes additional pollution and environmental degradation.
Transportation or transmission to individual user, eventual use, and discarding
Noise; ugliness; thermal water pollution; pollution of air, water, and soil; solid and radioactive wastes; safety and health hazards; heat
Fig , p. 344

35. Harvesting Nonrenewable Resources Costs
Ownership costs – equipment, labor, safety (insurance), environmental costs (reclamation, pollution control, air monitors, water treatment, etc.), taxes
External costs – processing the resource, transporting the resource
Marginal costs – research: finding new sources of the resource and new ways to harvest it

36. Benefits Direct – money received for resources; provides many jobs
Indirect – land can be reclaimed (brought back to original condition) and sold for profit.

37. ENVIRONMENTAL EFFECTS OF USING MINERAL RESOURCES
Minerals are removed through a variety of methods that vary widely in their costs, safety factors, and levels of environmental harm.
A variety of methods are used based on mineral depth.
Surface mining: shallow deposits are removed.
Subsurface mining: deep deposits are removed.

38. Removal Methods Surface Mining
Description – if resource is <200 ft. from the surface, the topsoil is removed (and saved), explosives are used to break up the rocks and to remove the resource, reclamation follows
Benefits – cheap, easy, efficient
Costs – tears up the land (temporarily), byproducts produce an acid that can accumulate in rivers and lakes

39. Removal Methods (Continued)
Underground Mining
Description – digging a shaft down to the resource, using machinery (and people) to tear off and remove the resource
Benefits – can get to resources far underground
Costs – more expensive, more time-consuming, more dangerous

40. Removal Methods (Continued)
Reclamation
Description – returning the rock layer (overburden) and the topsoil to a surface mine, fertilizing and planting it
Benefits – restores land to good condition
Costs – expensive, time-consuming

41. Open-pit Mining
Machines dig holes and remove ores, sand, gravel, and stone.
Toxic groundwater can accumulate at the bottom.
Figure 15-11

42. Area Strip Mining
Earth movers strips away overburden, and giant shovels removes mineral deposit.
Often leaves highly erodible hills of rubble called spoil banks.
Figure 15-12

43. Contour Strip Mining Used on hilly or mountainous terrain.
Unless the land is restored, a wall of dirt is left in front of a highly erodible bank called a highwall.
Figure 15-13

44. Mountaintop Removal
Machinery removes the tops of mountains to expose coal.
The resulting waste rock and dirt are dumped into the streams and valleys below.
Figure 15-14

46. Environmental Effects of Using Mineral Resources
Section 16-6
Environmental Effects of Using Mineral Resources

47. ENVIRONMENTAL EFFECTS OF USING MINERAL RESOURCES
The extraction, processing, and use of mineral resources has a large environmental impact.
Figure 15-9

48. Mining Impacts
Metal ores are smelted or treated with (potentially toxic) chemicals to extract the desired metal.
Figure 15-15

49. Supplies of Mineral Resources
Section 16-7
Supplies of Mineral Resources

50. SUPPLIES OF MINERAL RESOURCES
The future supply of a resource depends on its affordable supply and how rapidly that supply is used.
A rising price for a scarce mineral resource can increase supplies and encourage more efficient use.

51. Specific Resources & Their Uses
Limestone – abundant locally, formed from layers of seashells and organisms under pressure as they were covered; used in sidewalks, fertilizers, plastics, carpets, and more
Lead – used in batteries and cars
Clay – used to make books, magazines, bricks, and linoleum
Gold – besides being used as money and for jewelry, gold is used in medicine (lasers, cauterizing agents) and in electronics (circuits in computers, etc.)

52. United States Central – diamonds (Arkansas), bituminous coal
West – bituminous and subbituminous coal, gold, silver, copper
East – anthracite coal, bituminous coal
South – some gold (SC), bituminous coal
North – bituminous coal, some gold (SD, WI)

53. Alabama
Crushed stone, including limestone, dolomite, marble, granite, sandstone, and quartzite, contributes to a thriving mineral industry in the state.
Stone, along with sand, gravel, and clay, makes up a multi-million dollar nonfuel minerals industry in Alabama.
In 2007, the value of these produced minerals was $1.34 billion.
Approximately 9.1 metric tons of nonfuel minerals are required every year for every person in the United States to maintain the current standard of living.
Materials mined in Alabama such as bauxite, chalk, recovered sulfur, salt, and shale are used extensively in both construction and industry.

55. SUPPLIES OF MINERAL RESOURCES
Depletion curves for a renewable resource using three sets of assumptions.
Dashed vertical lines represent times when 80% depletion occurs.
Figure 15-16

56. SUPPLIES OF MINERAL RESOURCES
New technologies can increase the mining of low-grade ores at affordable prices, but harmful environmental effects can limit this approach.
Most minerals in seawater and on the deep ocean floor cost too much to extract, and there are squabbles over who owns them.

57. 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 15-17

58. USING MINERAL RESOURCES MORE SUSTAINABLY
Scientists and engineers are developing new types of materials as substitutes for many metals.
Recycling valuable and scarce metals saves money and has a lower environmental impact then mining and extracting them from their ores.

59. Sustainable Use of Nonrenewable Minerals
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.
Figure 15.18
Solutions: ways to achieve more sustainable use of nonrenewable mineral resources. QUESTION: Which two of the solutions do you think are the most important?
• Have the mineral-based wastes of one manufacturing process become the raw materials for other processes.
• Sell services instead of things.
• Slow population growth.
Fig , p. 351

60. Case Study: The Ecoindustrial Revolution
Growing signs point to an ecoindustrial revolution taking place over the next 50 years.
The goal is to redesign industrial manufacturing processes to mimic how nature deals with wastes.
Industries can interact in complex resource exchange webs in which wastes from manufacturer become raw materials for another.

61. Case Study: The Ecoindustrial Revolution
Figure 15-19

62. Sulfuric acid producer
Sludge
Pharmaceutical plant
Local farmers
Sludge
Greenhouses
Waste heat
Waste heat
Waste heat
Fish farming
Waste heat
Surplus natural gas
Electric power plant
Fly ash
Oil refinery
Surplus sulfur
Waste calcium sulfate
Figure 15.19
Solutions: the industrial ecosystem in Kalundborg, Denmark, reduces waste production by mimicking a natural food web. The wastes of one business become the raw materials for another. QUESTION: Is there an industrial ecosystem near where you live or go to school? If not, why not?
Waste heat
Cement manufacturer
Surplus natural gas
Sulfuric acid producer
Wallboard factory
Area homes
Fig , p. 352