Chapter 7Weathering and Erosion

Before we begin understand:

Introduction to Weathering and Erosion

http://www.youtube.com/watch?v=R48zYr-S7v0 Before watching the video write

these questions down. What is weathering? How does this

happen? What is erosion? How does this

happen? Based on what you now know: How

did the Santa Elena Canyon form? Explain.

Graham Cracker Activity

Listen to the teacher for instructions. Please use the paper towel to prevent mess.

Chapter 7 Word Study Guide Weathering Mechanical

Weathering Frost Wedging Chemical

Weathering Oxidation Erosion Deposition

WORD

Definition

Your Definition

Picture

Composition Notebook

Let’s make a book!

Weathering

Examples of weathering With your table partner, discuss what

is going on in these pictures. What is happening?

Mechanical Weathering

The type of weathering in which rocks and minerals break down into smaller pieces. Physical Weathering

Factors Temperature Pressure

Temperature (Notebook)

On page 164 What property of water leads to the

weathering of rocks? Explain (Think about states of matter)

What is frost wedging?

Pressure (Notebook)

Read page 165 Give two

examples of how pressure can help in the weathering process.

Chemical Weathering (Notebook)

What is the difference between mechanical (physical) weathering and chemical weathering?

Agents: Water Oxygen Carbon dioxide Acid precipitation

Weathering Agents

Water Good solvent

Oxygen Oxidation Iron can combine with atm O2 (form new

minerals) Carbon Dioxide

Weak acid precipitation (CO2 + H2O) Dissolves certain rocks

Acid Precipitation SO2, CO2, NO’s (Combine with O and H2O) <5.6 on pH scale Burning fuels

Rate of Weathering

Happens very slowly Effects

Climate Composition Surface area Topography

Climate

Temperature, precipitation, evaporation (Chemical)

Cool Climates (physical) With your shoulder partner

Why does cool climates not aid in chemical reactions?▪ Think states of matter.

Rock Type and Composition Different materials

break down at different rates. Put a piece of paper out

in a rain storm Put a piece of wood out

in a rain storm Hardness

Surface Area

Increase in surface leads to an increase in chemical weathering. Smaller pieces = faster

Topography

What is topography? Level ground = Less weathering Slopes = More weathering.

Turn In

Paragraph form: At least ½ page You will get extra credit for having more

than ½ page. Use the four steps to writing.

Explain how climate, composition, surface area, and topography speed up or slow down weathering.

Composition Notebook

Explain how the rate of reaction speeds up and slows down when it comes to weathering. MAKE SURE YOU USE EXAMPLES AND

EXPLAIN