Kaley and Jordan

WEATHERING AND MASS MOVEMENT

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

VOCABULARY

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

EROSION

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.

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.

Mechanical weathering Chemical weathering

Mechanical weathering Chemical weathering

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

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.

MASS MOVEMENT