Weathering and Erosion

Is the breaking down and changing of rocks near Earth’s surface

Two Types:

Mechanical (physical)  

Chemical

Physical forces break rock into smaller and smaller pieces without changing the rock’s mineral composition.

Frost Wedging

Unloading

Biological Activity

Expansion of freezing water in cracks and crevices

Eventually breaking rocks into pieces

Sections of rock that are wedged loose are called talus

The uplift and erosion of rocks overlying igneous rocks because pressure on igneous rocks is reduced

Exfoliation—slabs of outer rock separate and break loose

The activity of organisms, including plants, burrowing animals, and humans

Plant roots wedge into rocks breaking them apart

the transformation of rock into one or more new compounds.

Water dissolves minerals and rocks.

-This results in the formation of clay minerals.

Oxygen in atmosphere combines with iron in rocks & minerals.This results in rust (red rocks).

Carbon Dioxide combines with water (H2O) in atmosphere or soil forming weak carbonic acid. This results in clay or caves.

Acid precipitation … rain, snow, sleet mixed with gases in the atmosphere that turn these forms of water into a weak acid (pH < 5.0).

sulfur dioxide and nitrogen oxide The most common source – coal-fired power plants

It is also known as acid rain

It causes lakes to become more acidic than living things can handle. AND… It chemically weathers nonliving things like statues and buildings

The wearing away and moving of surface materials by gravity, water, wind, or glaciers.

The wearing away and moving of surface materials by gravity, water, wind, or glaciers.

4 Agents of Erosion: 

1.Wind

2.Water

3.Gravity

4.Glaciers