1. Intro to World Geography
Changes to the Earth

2. Chapter Key Concepts Major geologic processes
Earthquakes and volcanoes
Minerals, rocks, and the rock cycle
Finding and extracting mineral resources
Non-renewable mineral resources

4. Sections 1 and 2 Key Concepts
What are the major geological processes that occur within the earth and its surface?
What is the Plate Tectonic Theory?
What types of plate boundaries occur as the plates move around the surface?
What is erosion and weathering?

5. Earth A Dynamic Planet
Has the Earth always looked the same as it looks today?
Geology: the subject that is devoted to studying the dynamic processes occurring on the earth’s surface and the interior.

7. Earth A Dynamic Planet
Sometimes the changes on earth’s surface occur quickly, other times they take a LONG time.

8. Earth A Dynamic Planet
Our planet is constantly changing due to forces at play within the earth.

9. Geologic Processes: Structure of the Earth
The three major zones:
CRUST
MANTLE
CORE

10. Internal Geological Processes

11. Features of the Crust and Upper Mantle
Fig p. 333

12. Plate Tectonic Theory
Earth’s surface is broken into about 15 huge rigid plates that are moving very slowly across the earth surface.
Lithosphere Plates
UNIFYING THEORY OF GEOLOGY

13. Plate Tectonic Theory

14. Plate Tectonics Divergent boundary Convergent boundary Subduction zone
Transform fault
Refer to Fig p. 334

16. Earth’s Major Tectonic Plates
Fig. 16-4, p. 335

18. Tectonic Theory Helps Explain
Mountain “building” occurs mainly along plate boundaries

19. Tectonic Theory Helps Explain
Most volcanoes are found at divergent and convergent plate boundaries

20. Tectonic Theory Helps Explain
Most earthquakes occur near plate boundaries.

21. External Earth Processes
Erosion: the process by which material such as rocks, sand and soil are dissolved, loosened, or worn away from one part of the earth’s surface and deposited elsewhere.
Water causes most erosion on earth

22. External Earth Processes
Mechanical weathering: large rock pieces are broken into smaller fragments.
Water is main agent

23. Glacial erosion versus stream erosion

24. External Earth Processes
Frost wedging: water collects in the pores and cracks of rocks and expands when frozen, then splits the rock.
Causes street potholes to expand.

25. External Earth Processes
Chemical weathering: process by which chemicals naturally break down rocks and soil.
Examples: rusting, acid rain

26. External Earth Processes
Biological weathering: the conversion of rocks or minerals into smaller particles by living organisms.
Example: roots breaking into cracks of rocks.

27. Sections 1 and 2 Review
What are the major geological processes that occur within the earth and its surface?
What is the Plate Tectonic Theory?
What types of plate boundaries occur as the plates move around the surface?
What is erosion and weathering?

29. Sections 3 and 4 Key Concepts
What are earthquakes? Where do they occur most frequently?
What are volcanoes? Where do they occur most frequently?
What are minerals and rocks? What is the rock cycle?
What are nonrenewable mineral resources?

30. Natural Hazards: Earthquakes
Earthquakes occur when part of the crust suddenly fractures along a fault to relieve stress and gives off energy as shockwaves that travel through the earth
Fig p. 337

31. Natural Hazards: Earthquakes

32. Natural Hazards: Earthquakes
Richter Scale: the scale used to measure the intensity of an earthquake.
< 4 insignificant
4-5 minor
5-6 damaging
6-7 destructive
7-8 major
> 8 great

33. Natural Hazards: Earthquakes
Primary Impacts
Ground shaking
IMPACTS:
Buildings, highway overpasses, dams, pipelines, bridges, etc.

34. Natural Hazards: Earthquakes
Secondary Impacts
Fires
Flooding
Subsidence
Tsunamis

35. Expected Earthquake Damage
Canada
United States
No damage expected
Minimal damage
Moderate damage
Severe damage
Fig p. 337

36. Natural Hazards: Volcanic Eruptions
extinct
volcanoes
magma
reservoir
central
vent
conduit
Solid
lithosphere
Upwelling
Partially molten
asthenosphere
Fig p. 338

37. Natural Hazards: Volcanic Eruptions
Volcanoes occur where magma reaches the earth’s surface through a crack in the crust…usually near divergent or convergent plate boundaries.

38. Natural Hazards: Volcanic Eruptions
Impacts:
Ejects – hot ash, hot gases, lava, chunks of rocks.
Mudflows
Acid Rain
Earthquakes
Some eruptions violent, others not so violent

39. Minerals and Rocks
The earth’s crust consists of solid inorganic elements and compounds called minerals and masses of 1 or more mineral we call rocks
Mineral: an element or inorganic compound that occurs naturally, is solid, and in fixed crystal structure. (gold, sulfur, copper)

40. Minerals and Rocks
Igneous Rocks: formed from cooled and hardened magma or lava.
Source a many non-fuel mineral resources.
Examples: granite, basalt.

41. Minerals and Rocks
Sedimentary Rocks: formed from compressed and hardened sediment such as sand and clay.
When sediment is eroded and carried away by rivers and streams it often build up in layers.
Examples: sandstone, limestone, shale.

42. Minerals and Rocks
Metamorphic Rocks: produced by existing rocks are subjected to enormous heat and pressure.
Usually occurs deep in the earth.
Examples: marble, slate

43. Minerals and Rocks
Rock Cycle: the interaction of physical and chemical changes that change rocks from one form to another.
Happens very slowly over long periods of time.

45. Rock Cycle Sedimentary Rock Heat, Pressure Heat, Igneous Rock
Shale, Sandstone,
Limestone
Deposition
Transport
Erosion
Rock Cycle
Heat,
Pressure
Weathering
Heat,
Pressure
Igneous Rock
Granite, Pumice,
Basalt
Metamorphic Rock
Slate, Quartzite,
Marble
Magma
(Molten Rock)
Fig p. 339

46. Nonrenewable Mineral Resources
Nonrenewable Mineral Resource: is a concentration of naturally occurring material that can be extracted and used at a reasonable cost.
It takes the earth so long to produce so we consider them nonrenewable.

47. Nonrenewable Mineral Resources
Metallic: iron, copper, aluminum are examples of some metallic nonrenewable mineral resources.
Copper mine

48. Nonrenewable Mineral Resources
Non-Metallic: sand, salt, clay, soil.
Sand mine

49. Nonrenewable Mineral Resources
Energy Sources: coal, oil, natural gas, uranium.

50. Nonrenewable Mineral Resources
Ores: is rock containing enough or one or more metallic minerals to be mined profitably.
We use more than 40 metals extracted from ores for everyday items.
Gold ore

51. Nonrenewable Mineral Resources: Categories
Identified: known location, quantity and quality.
Undiscovered: potential supply assumed to exist based upon theory.
Reserves: identified sources from which can be extracted at current prices.
Other: undiscovered and unidentified.
Fig p. 340

52. Sections 3 and 4 Review
What are earthquakes? Where do they occur most frequently?
What are volcanoes? Where do they occur most frequently?
What are minerals and rocks? What is the rock cycle?
What are nonrenewable mineral resources?

54. Sections 5, 6 and 7 Key Concepts
How are buried mineral deposits found? How are they then removed?
What are some environmental impacts of using nonrenewable mineral resources?
What is a typical life cycle of a nonrenewable metal resource?
Do we have enough nonrenewable mineral resources?

55. Finding Nonrenewable Mineral Resources
Promising underground deposits of minerals are located using various techniques.

56. Finding Nonrenewable Mineral Resources
Satellite and air imagery:
ariel photos and images from space
help locate outcrops.
Radiation detectors:
To find radioactive minerals like
uranium.

57. Finding Nonrenewable Mineral Resources
Magnetometers: measures changes in earth’s magnetic field caused by minerals like iron
Seismic surveys: detonating explosives to see how sound waves travel through ground.

58. Finding Nonrenewable Mineral Resources

59. Extracting Nonrenewable Mineral Resources:
Open-pit (surface mining): machines dig holes and remove ores (common for iron, copper, limestone, sand)
Dredging (surface mining): chain buckets scrape the bottom underwater

60. Extracting Nonrenewable Mineral Resources:
Area strip (surface mining): big machine move strips away to reach ore.
Contour strip (surface mining): used in hilly areas to remove tops of mountains.

61. Extracting Nonrenewable Mineral Resources:
Subsurface mining impacts much less land, but…
Leaves some resource behind
Is more dangerous
Is more expensive

66. Extracting, processing and using mineral resources has environmental impacts.

67. Environmental Effects of Mining Mineral Resources
Disruption of land surface
Subsidence
Erosion of solid mining waste
Acid mine drainage
Air pollution
Storage and leakage of liquid mining waste

68. Environmental Effects of Mining Mineral Resources
Fig p. 344

69. More Environmental Impacts of Nonrenewable Mineral Resources
Surface mining
Subsurface mining
Overburden
Room and pillar
Spoil
Longwall
Open-pit
Dredging
Refer to Figs and 15-5, p. 341 and 342
Strip mining

70. Acid mine drainage.

72. Processing Mineral Resources
Ore mineral
Gangue
Tailings
Smelting

74. Supplies of Mineral Resources
Economic depletion
Depletion time
Foreign sources
Environmental concerns
Economics
New technologies
Mining the ocean
Finding substitutes
Fig p. 346

75. Sections 5,6,7 Review
How are buried mineral deposits found? How are they then removed?
What are some environmental impacts of using nonrenewable mineral resources?
What is a typical life cycle of a nonrenewable metal resource?
Do we have enough nonrenewable mineral resources?