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

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

Geologic Processes Structure of the Earth Fig. 10-2 pg 204

Features of the Crust Fig. 10-3 p. 205

Plate Tectonics

Internal Earth Processes Divergent boundaries Convergent boundaries Subduction zone Transform fault Ring of Fire Fig. 10-6 p. 208

Ring of Fire

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

Tsunami Meulaboh, Indonesia (Before)

Tsunami Meulaboh, Indonesia (After)

Tsunami Banda Aceh, Indonesia (Before)

Tsunami Banda Aceh, Indonesia (After)

Expected Earthquake Damage Canada United States No damage expected Minimal damage Moderate damage Severe damage Fig. 10-10, p 211

Natural Hazards: Volcanic Eruptions extinct volcanoes magma reservoir central vent conduit Solid lithosphere Upwelling Partially molten asthenosphere Fig. 10-11, p 211

External Earth Processes Erosion Mechanical weathering Frost wedging Chemical weathering

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

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. 10-8 p. 210

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. 10-12, p 212

Increasing percentage sand Soil Properties Water High permeability Low permeability Fig. 10-17 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. 10-16 p. 216

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

Soils: Erosion Sheet erosion Rill erosion Gully erosion

Areas of serious concern Stable or nonvegetative areas Global Soil Erosion Areas of serious concern Areas of some concern Stable or nonvegetative areas Fig. 10-19, p 218

Soils: Degradation Desertification Salinization Waterlogging Evaporation Transpiration Waterlogging Less permeable clay layer Fig. 10-22, p 221

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

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