3-1 changing earth's surfaceThe material moved by erosion is sediment.
Madison River Canyon is a spectacular example of erosion. Deposition occurs where the agents of erosion lay down sediment. Erosion is the process by which natural forces move weathered rock and soil from one place to another. Gravity, running water, glaciers, waves, and wind can all cause erosion. Weathering, erosion, and depostition act together in a cycle that wears down and builds up Earth's surface. The different types of mass movement include landslides, mudslides, slump and creep. LANDSLIDE: This is the most destructive type of mass movement. This occurs when rock and soil slide quickly down a steep slope. MUDFLOWS: A mudflow is the rapid downhill movement of a mixture of water rock and soil. Mudflows often occur after heavy rains. SLUMP: In the type of mass movement known as slump, a mass of rock and soil suddenly slips down a slope. Slumps often occur when water slaps the base of a mass of soil that is rich in clay. CREEP: Creep is the very slow downhill movement of an hour hand on a clock, creep is so slow you can barely notice it. Creep may tilt objects at spooky angles. |
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main ideasWeathering, erosion, and deposition act to wear down and build up Earth's surface.
Gravity pulls sediment down hills in the process of mass movement. There are four main types of mass movement: Landslides, mudslides, slump, and creep. |
Key Terms
Deposition Sediment Mass Movement |
Checkpoint QuestionsWhat happens to sediment as a result of erosion and deposition?
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Section Review1. Explain the difference between erosion and depostiton.
2. What force causes erosion? 3. What are four types of mass movement? 4. Thinking Critically Relating Cause and Effect Why would a lanslide be more likely on a steep mountain than on a gently sloping hill? |