Page 458 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

14
Weathering, Karst Landscapes, and Mass Movement
In March 2011, weeks of heavy rains trig-
concepts
Key LeARNING
After reading the chapter, you should be able to:
• Describe the dynamic equilibrium approach to the study of landforms, and illustrate the forces at work on materials residing on a slope.
• Define weathering, and explain the importance of parent rock and joints and fractures in rock.
• Describe the physical weathering processes of frost action, salt-crystal growth, and pressure-release jointing.
• Explain the chemical weathering processes of hydration, hydrolysis, oxidation, carbonation, and dissolution.
• Review the processes and features associated with karst topography.
• Categorize the various types of mass movements, and identify examples of each by moisture content and speed of movement.
gered landslides that devastated several neighbourhoods in La Paz, Bolivia, crumpling roads and flattening hundreds of homes. No fatalities occurred from this event, though landslides kill 8 000 people on average every year worldwide. Landslides represent one type of mass movement, or mass wasting, process in which large bodies of earth mate- rials are carried downslope in sudden events. [Aizar Raldes, AFP/Getty Images.]