Chapter 3: Erosion and Deposition Section 1: Changing Earth’s Surface

Wearing Down & Building Up Erosion- the process by which natural forces move weathered rock and soil from one place to another Deposition- occurs where the agents of erosion deposit, or lay down, sediment

Wearing Down & Building Up Weathering, erosion, and deposition act together in a cycle that wears down and builds up Earth’s surface. This cycle, called the geologic cycle, has continued for billions of years.

Mass Movements gravity- the force that moves rock and other materials downhill mass movement- any one of several processes that move sediment downhill

Mass Movements The different types of mass movement include landslides, mudflows, slump, and creep.

Landslides Occurs when rock and soil slide rapidly down a steep slope May contain only a small amount of rock and soil Can be triggered by earthquakes

Landslides

Landslides

Mudflows The rapid downhill movement of a mixture of water, rock, and soil Can contain as much as 60% water Can be triggered by earthquakes

Mudflows

Mudflows

Slump A mass of rock and soil rapidly slips downhill Moves as one large piece

Slump

Creep The very slow downhill movement of rock and soil Can occur on gentle slopes Can form from the freezing and thawing of water in cracked layers

Creep

Creep

Creep

The end.