Weathering and Mass Movement
Weathering |
There are two types of weathering, mechanical and chemical. Mechanical weathering is the process of physically breaking rock into smaller fragments. When rain falls, rocks dissolve the water. The water in the rock will freeze when the temperature decrease at night and it forms ice. The water will expand when water freezes, so the expansion create cracks in rocks. Then the ice will thaw as the temperature increases at daytime. These processes repeat overtime and erosion happens.
Another type of weathering is called the chemical weathering. Chemical weathering is the process in which rock is broken down by chemical reactions. This weathering is mainly caused by water and acid water. Water creates chemical reactions and these reactions create rocks and new minerals. Acid water and carbon dioxide combine to form carbonic acid. The carbonic acid dissolves many minerals, such as calcite. The rusting of minerals that are rich in iron, involves oxidation. This rusting forms new minerals that often have red or brown color. |
Mass Movement |
Mass movement is a downward movement of rock and soil due to gravity. Gravity moves loose materials down a slope. Landslides, mudflows, creep, and slumping are some forms of mass movement.
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Landslides• A rapid movement of large amounts or rock and soil
• Usually after heavy rains or after earthquakes |
Mudflows• Rapid movements of soil and other sediment mixed with water
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Creep• Occurs when soil gradually moves down a slope
• Often because of the formation of ice • A rapid movement of large amounts or rock and soil |
Slumping• Weak layers of soil or rock suddenly move downslope as single unit
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