1. Happy Monday! Please pick up the handouts and have a seat.
You may also look at your test scores on the board
Test corrections are to be done by Friday. Sign up is outside of my door
If you did not finish your test, you will do so after our notes today
Prepare to change seats once I start class (your choice, just can’t be at the same table)

2. Think About it If something is “weathered”, what do you think of?
Do you know what the two types of weathering are?

3. Mechanical Weathering
Physical Weathering- the process by which rocks break down into smaller pieces by physical means
Frost Wedging- alternate freezing & thawing of water

4. Exfoliation- peeling away of large sheets of loosened material
Root/plant wedging: the process in which plant roots cause rocks to
break as the plant and roots grow

5. Abrasion- when rocks rub against each other

6. Chemical Weathering
Chemical weathering: the process by which rock is broken down chemically due to chemical interactions with the environment
Oxidation- when oxygen unites chemically with a mineral. Ex. Rust (iron oxide)

7. Hydration- when water unites chemically with minerals.

8. Mechanical Weathering
Chemical weathering
Pressure/stress release
Organic acid (moss, lichen, or pine needles)
Abrasion by wind, water, or human activity
Hydrolysis (reacting with water)
Gravity (mass wasting)
Acid precipitation
Exfoliation
Hydration (dissolving in water)
Ice wedging
Oxidation (metal and oxygen)
Biological (animal burrows, roots)

9. Rates of Weathering
Surface area - If particle size goes down then, weathering rate goes up (more surface area exposed).
Weathering eats away sharp edges first (makes things round)

10. Rates of Weathering
Climate- the average weather of a location over time

11. Differential Weathering
Different minerals weather at different rates.
Hard rocks weather slowly
Soft rocks weather quickly