1. Geology: Processes, Hazards, and Soils Chapter 10
“Civilization exists by geological consent to change without notice.”
Will Durant

2. Key Concepts Internal geologic processes External geologic processes
Minerals, rocks and the rock cycle
Earthquakes and volcanoes
Soil structure and formation
Soil conservation

3. Geologic Processes
Structure of the Earth
Fig pg 204

5. Features of the Crust
Fig p. 205

6. Plate Tectonics

7. Internal Earth Processes
Divergent boundaries
Convergent boundaries
Subduction zone
Transform fault
Ring of Fire
Fig p. 208

10. Ring of Fire

12. Natural Hazards: Earthquakes
Features
Magnitude
Aftershocks
Primary effects
Secondary effects
Fig. 10-9, p 210

14. Tsunami
Meulaboh, Indonesia (Before)

15. Tsunami
Meulaboh, Indonesia (After)

16. Tsunami
Banda Aceh, Indonesia (Before)

17. Tsunami
Banda Aceh, Indonesia (After)

18. Expected Earthquake Damage
Canada
United States
No damage expected
Minimal damage
Moderate damage
Severe damage
Fig , p 211

19. Natural Hazards: Volcanic Eruptions
extinct
volcanoes
magma
reservoir
central
vent
conduit
Solid
lithosphere
Upwelling
Partially molten
asthenosphere
Fig , p 211

20. External Earth Processes
Erosion
Mechanical weathering
Frost wedging
Chemical weathering

21. Minerals and Rocks Rock Types Mineral (diamond, bauxite)
Igneous (granite, lava rock)
Sedimentary (limestone, sandstone)
Metamorphic (marble, slate)
Rock Types

22. The Rock Cycle Sedimentary Rock Heat, Pressure Heat, Igneous Rock
Shale, Sandstone,
Limestone
Deposition
Transport
Erosion
Heat,
Pressure
Weathering
External Processes
Internal Processes
Heat,
Pressure
Igneous Rock
Granite, Pumice,
Basalt
Metamorphic Rock
Slate, Quartzite,
Marble
Magma
(Molten Rock)
Refer to
Fig p. 210

23. Soils: Formation Soil horizons Soil profile Humus Fig. 10-12, p 212
O horizon
Leaf litter
A horizon
Topsoil
B horizon
Subsoil
C horizon
Parent
material
Mature soil
Young soil
Regolith
Bedrock
Immature soil
Fig , p 212

24. Increasing percentage sand
Soil Properties
Water
High permeability
Low permeability
Fig p. 217
Infiltration
Leaching
Texture
Porosity/ permeability
Structure pH
100%clay
Increasing
percentage silt
percentage clay 20 40 60 80
100%sand
100%silt
Increasing percentage sand
Fig
p. 216

26. Table 10-1 p. 216
Texture Nutrient Infiltration Water-Holding Aeration Tilth
Capacity 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

27. Soils: Erosion
Sheet erosion
Rill erosion
Gully erosion

28. Areas of serious concern Stable or nonvegetative areas
Global Soil Erosion
Areas of serious concern
Areas of some concern
Stable or nonvegetative areas
Fig , p 218

29. Soils: Degradation Desertification Salinization Waterlogging
Evaporation
Transpiration
Waterlogging
Less permeable
clay layer
Fig , p 221

30. Solutions: Soil Conservation
Conventional-tillage
Conservation tillage
Cropping methods
Windbreaks
Land Classification

31. Soil Restoration Organic fertilizer Animal manure Green manure Compost
Crop rotation
Commercial inorganic fertilizer