Soil & Weathering. The breakdown of materials of Earth’s crust into smaller pieces. Weathering.

Soil & Weathering

The breakdown of materials of Earth’s crust into smaller pieces.

Weathering

Mechanical Weathering

Process by which rocks are broken down into smaller pieces by external conditions.

Types of Physical weathering Frost wedging Plant roots Friction and impact Burrowing of animals Temperature changes

Frost Wedging

Plant Roots

Friction and Repeated Impact

Burrowing of Animals

Temperature Changes

Questions

Chemical Weathering

The process that breaks down rock through chemical changes.

The agents of chemical weathering Water Oxygen Carbon dioxide Living organisms Acid rain

Water

Water weathers rock by dissolving it

Oxygen Iron combines with

oxygen in the presence of water in a processes called oxidation

The product of oxidation is rust

Carbon Dioxide

CO2 dissolves in rain water and creates carbonic acid

Carbonic acid easily weathers limestone and marble

Living Organisms

Lichens that grow on rocks produce weak acids that chemically weather rock

Acid Rain Compounds from burning coal, oil and gas

react chemically with water forming acids. Acid rain causes very rapid chemical

weathering Acid rain has the same ph level as tomato

juice

Soil

What is soil? Loose mixture of

weathered rock, organic matter, water, and air

Is chemically and physically different from parent material

Soil Horizon

Soils have distinct zones that roughly parallel land surface

Horizon Layers Typical soil profile

O horizon -- dark organic matter

A horizon -- contains some organic matter but many minerals are removed from this layer; Lighter-colored than O

B horizon -- contains decomposed rock such as clay, iron oxides, calcite; may be red, yellow, or tan

C horizon -- slightly altered parent material

Soil Horizons in Archaeology

Ashland, home of Henry Clay

Soil Horizon

Can you see the layers?

Monticello, VA

Can you figure out the layers?Which is horizon O, A, B, & C?

Erosion

The process by which water, ice, wind or gravity moves fragments of rock and soil.

Water Erosion

Rivers, streams, and runoff

Ice Erosion

Glaciers

Wind Erosion

Mass Movements

Landslides, mudslides, slump and creep

landslide clip.mpeg

POP QUIZ TIME!!

You may use your notes

POP QUIZ TIME!!

What is mechanical weathering?

POP QUIZ TIME!!

1 What are the two types of weathering?

POP QUIZ TIME!!

1 What are the two types of weathering?

2 Acid rain is which type of weathering?

POP QUIZ TIME!!

1 What are the two types of weathering?

2 Acid rain is which type of weathering?

3 Iron combines with what 2 things to form rust?

POP QUIZ TIME!!

1 What are the two types of weathering?

2 Acid rain is which type of weathering?

3 Iron combines with what 2 things to form rust?

4 Frost wedging & animal burrowing are which type of weathering?

POP QUIZ TIME!!

1. What are the two types of weathering?

2. Acid rain is which type of weathering?3. Iron combines with what 2 things to

form rust?4. Frost wedging & animal burrowing are

which type of weathering?5. Which horizon has dark, organic

matter?

POP QUIZ TIME!!1. What are the two types of weathering?

1. mechanical & chemical

2. Acid rain is which type of weathering?1. chemical weathering

3. Iron combines with what 2 things to form rust?

1. oxygen & water

4. Frost wedging & animal burrowing are which type of weathering?

1. mechanical

5. Which horizon has dark, organic matter?1. Horizon O