Weathering and Mass movement

1. Weathering and Mass movement Kaley and Jordan

2. Vocabulary • Erosion- the process that wears down and carries away rock and soil. • Weathering- the process by which rocks are chemically altered or physically broken into fragments. • Mechanical weathering- the process of physically breaking rock into smaller fragments. • Abrasion- a form of mechanical weathering that occurs when rocks scrape or grind against one another • Chemical weathering-the process in which rock is broken down by chemical reactions • Mass movement-the downward movement of rock and soil due to gravity, including landslides, mudflows, creep, and slumping

3. Erosion • What is erosion? • Erosion acts through weathering, the force of gravity, and through the movement of streams, groundwater, glaciers, wind, and waves. • Over time, erosion breaks down even the tallest mountain. • Erosion wears down and carries away rock and soil. • Erosion cuts canyons through solid rock and wears away the cliffs above beaches

5. weathering • What is weathering? • Weathering is the process by which rocks are chemically altered or physically broken down into fragments at or near earth’s surface. • Two forms of weathering are: mechanical and chemical, they cause rocks to disintegrate or decompose.

6. Mechanical weathering Chemical weathering • Mechanical weathering is the process of physically breaking rock into smaller fragments. • Mechanical weathering occurs through frost wedging, abrasion, and growth of plant roots. • The most common form is frost wedging. • Chemical weathering is a process in which rock is breaking down by chemical reactions. • Chemical weathering evolves chemical reactions that dissolve the minerals making up rock or change them into new minerals. • Water is the main agent of chemical weathering because it is slightly acidic.

7. Mechanical weathering Chemical weathering

8. Mass movement • Mudflow-mudflow is a rapid mass movement of soil and other sediments mixed together Mudflow tends to occur in areas where fine sediment has collected in thick layers. • Creep-creep occurs when soil gradually moves down a slope. Creeps occur because of the formation of ice. • Slumping- slumping occurs when weak layers of soil and rock move downslope as a single unit. • What is mass movement? • Mass movement is the downward movement of rock and soil due to gravity. • Landslides, mudflows, creep, and slumping are different kinds of mass movement. • Landslides- landslides often occur after heavy rains or after earthquakes loosen materials on a steep slope. Landslides that occur on the sides of mountains can destroy entire towns