Types of Weathering

Mechanical

Chemical

What is Mechanical Weathering?

The breakdown of rocks without changing the

chemical composition of the rock.

1. Frost Action

Freezing and thawing that results in breaking the rock apart into pieces.

2. Abrasion

Wearing away of rocks by wind or water; can polish the affected rocks.

3. Gravity

As rocks fall, they collide with each other and break apart.

4. Organic Activity: Root Pry

Plant roots can grow into crevices within rocks andbreak them apart.

5. Wetting and Drying

Constant swelling and shrinking makes rocks crack.

6. Joint Sheeting

The removal of large masses of rock causes rocks to expand.

What is Chemical Weathering?

The process by which rocks are decomposed, dissolved or loosened

by chemical processes to form residual materials.

1. Hydrolysis

The chemical reaction of water with other substances.

Feldspar +Water = Clay

Feldspar

A Clay Cliff

2. Plant Acids

Acids formed by the decaying of plants and animals;eats away rocks.

3. Sulfuric Acid

Pollution from smog dissolvesin rainwater (acid rain) and eatsaway at rocks.

4. Oxidation

The chemical reaction of oxygen with other substances (rust).

5. Carbonation

Carbonic acid dissolves rocks and forms caves underground.

The End