Guided Notes about Weathering Section 7.1

Weathering Weathering is the process by which rocks on or near Earth’s surface break down and change.

Erosion Erosion is the removal and transport of weathered material from one location to another.

There are two types of weathering: Mechanical Chemical

Mechanical Weathering Mechanical weathering is the process by which rocks break down into smaller pieces. It is also called physical weathering and doesn’t involve any change in the rock’s composition.

Water Water is the most important agent of mechanical weathering, but wind also plays a role.

Two factors influence the amount of mechanical weathering that will occur: Temperature Pressure

Chemical Weathering Chemical weathering is the process by which rocks and minerals undergo changes in their composition as a result of chemical reactions.

There are four agents of chemical weathering: Water Oxygen Carbon dioxide Acid precipitation

Four factors affect the rate of weathering: Climate Rock type Surface area Topography

Climate Climate plays a role in weathering because certain climates encourage different types of weathering. Chemical weathering occurs most readily in warm, humid climates. Physical weathering occurs most readily in cool, dry climates.

Sedimentary Rocks Sedimentary rock types are more easily weathered than any other type of rock.

Surface area As the surface area of a rock increases due to weathering, the rate of weathering also increases.

Topography Rocks that are located on a slope are more likely to be weathered because gravity can cause them to move more readily.