Physical and Chemical Weathering

Two types of weathering

1. Physical (Mechanical) 2. Chemical

Acids in groundwater

Acidic groundwater can dissolve rock away underground that can cause very large cave systems.

Animal action

Can cause weathering because they burrow and dig, exposing rock and soil to the surface.

Acid precipitation

Chemicals combining with water in the air can make acid rain; this can dissolve minerals in rock faster than water.

Gravity abrasion

Falling rocks can hit other rocks below, causing them to break down.

Acids in living things

Living organisms, like lichens and moss, produce acids that can get into the cracks of rocks and cause them to break down.

Oxidation

Oxygen combines with minerals that have iron causing and reddish orange color change ("rusting").

Water abrasion

Rocks picked up and moved by water can bump into other rocks, causing them to break down. Running water also makes the rocks more rounded and smooth.

Plant growth

Roots can grow within the cracks of rocks, eventually causing the cracks to get bigger and breaking the rocks.

Wind abrasion

Small rock particles picked up by wind and blown at other rocks, causing them to break down.

Weathering

The breakdown of rock material by physical and chemical processes.

Chemical Weathering

The breakdown of rocks by chemical reactions. It changes the broken down rock into a new substance.

Physical Weathering

The breakdown of rocks into smaller pieces by physical changes.

Abrasion

The breaking down and wearing away of rock material by the mechanical action of other rock.

Oxidation; acid precipitation; acids in groundwater; acids in living things

Types of CHEMICAL weathering

Temperature change; pressure change; plant growth; animal action; wind, water and gravity (abrasion)

Types of PHYSICAL weathering

Ice wedging

Water gets into the cracks of rocks and freezes causing the cracks to get bigger.