Weathering Types of Weathering n n Mechanical physical

Types of Weathering n n Mechanical (physical) weathering Chemical weathering

Mechanical Weathering 6 causes: n Frost Wedging (Temperature) n Abrasion n Exfoliation n Trees

Where does Frost Wedging occur? n n Frost wedging can only occur in a

Exfoliation at Stone Mountain in Georgia

Abrasion n n Breaking and grinding away of solid rock by collisions with moving

Abrasion n results are smooth, round rocks.

Pressure Bedrock at great depths is under pressure from the overlying rock. When the

Chemical Weathering n 4 Causes: n n Water Oxygen Carbon dioxide Acid precipitation 17

Water / Hydrolysis n Hydrolysis is the process where water dissolves minerals.

Oxygen / Oxidation n n 21% of the atmosphere is Oxygen. Which readily combines

Carbon dioxide n n n Is released into the atmosphere by living organisms. When

Acid Precipitation n n Caused mainly by the oxidation of Sulfur dioxide and Nitrogen

n n These gases combine with Oxygen and Water in the atmosphere to form

Other formations from chemical weathering Karst topography is caused by dissolution n which leads

The Climate n Chemical weathering occurs most often in climates with warm temperatures and

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Weathering

Types of Weathering n n Mechanical (physical) weathering Chemical weathering

Mechanical Weathering 6 causes: n Frost Wedging (Temperature) n Abrasion n Exfoliation n Trees n Wind n Pressure

frost wedging can cause a landslide

frost wedging causes damage to roads.

Where does Frost Wedging occur? n n Frost wedging can only occur in a region that has temperatures that go above and below 32 degrees F. Frost wedging not likely in Florida

Exfoliation at Stone Mountain in Georgia

Exfoliation in the Sierra Nevada

Exfoliation in Yosemite National Park

Abrasion n n Breaking and grinding away of solid rock by collisions with moving particles. Abrasion takes place due to fast moving streams, waves and wind.

Abrasion n results are smooth, round rocks.

Trees n Tree roots can break up rocks.

Wind causes interesting shapes.

Pressure Bedrock at great depths is under pressure from the overlying rock. When the overlying rock layers are removed, the bedrock can expand. 15

Chemical Weathering

Chemical Weathering n 4 Causes: n n Water Oxygen Carbon dioxide Acid precipitation 17

Water / Hydrolysis n Hydrolysis is the process where water dissolves minerals.

Oxygen / Oxidation n n 21% of the atmosphere is Oxygen. Which readily combines with Iron to create new minerals. 19

Carbon dioxide n n n Is released into the atmosphere by living organisms. When it combines with water it forms Carbonic acid. H 2 O + CO 2= H 2 CO 3

Sinkholes form due to Carbonic acid…

…and so do Caves. 22

Acid Precipitation n n Caused mainly by the oxidation of Sulfur dioxide and Nitrogen oxides. which are released due to human activities. Sulfur dioxide forms from the burning of fossil fuels. Nitrogen oxides are emitted from motor vehicle exhausts.

n n These gases combine with Oxygen and Water in the atmosphere to form Sulfuric acid and Nitric acid. Which damage the shine and texture of stone monuments. 24

Other formations from chemical weathering Karst topography is caused by dissolution n which leads to the formation of an underground system. n

Karst Topography

The Climate n Chemical weathering occurs most often in climates with warm temperatures and high rainfall. n Physical weathering occurs most often in climates with cool temperatures and low rainfall.