RAP 1/22 pg. 41. What is weathering?2. As shown below, an

empty 1,000.-milliliter container has a mass of 250.0 grams. When filled with a liquid, the container and the liquid have a combined mass of 1,300. grams. What is the density?

RAP 1/23 pg 41. The picture below is an example of

what type of weathering?

2. Explain why you think this.

Topic: Weathering, Soil and Erosion

• Chapter 12 in book– Section: 12.1 - Weathering– Section: 12.2 - Soil– Section: 12.3 - Mass Movements & Erosion – Section: 12.4 - Soil as a Resource

Weathering: breakup of rock due to exposure to processes that occur on Earth’s surface

Two types:1. Chemical

-minerals are changed into different substances

2. Mechanical-split or broken into

smaller pieces*no change in composition

1. AbrasionMechanical

Breakdown of rock by grinding action

2. Frost Wedging

MechanicalWater freezes in the cracks of rocks and expands

Root Pry

Lichen - a symbiosis between algae and fungus. Secretes acid. It is the most important producer

of soil from rock.

3. Plant and Animal Activity

Mechanical

Chemical

Roots pry open crackx

Lichen secrete acid

4. Exfoliation

MechanicalPeeling of surface layers

5. Hydrolysis

ChemicalReaction of water with other substances

6. Acids

ChemicalDissolves minerals like calcite and rocks like limestone

19681908

7. Oxidation

ChemicalReaction of oxygen with other substances

Example: rust

Types of Chemical Weathering

??????????

??????????

??????????

oxidation

acid rain

hydrolysis

RAP 1/29 pg 41. Which rock was most likely found in

the bottom of a riverbed?

2. What type of weathering is responsible for the river rock?

Alka Seltzer Lab

1. Follow along with teacher demonstrations.

2. Answer Alka Seltzer Analysis Questions on pg. 6 (Due 1/30)

RAP 1/30 pg. 8

1.In the alka seltzer lab, what two things changed the weathering rates?

2. Which substance plays the most important role in chemical weathering?

Weathering Quiz (1/30)

Rates of Weathering1. Surface Area

2. Climate

3. Composition

a. More surface exposure = faster

a. Wet = faster; Dryer = slower

a. Faster = shale; Slower = quartz

Where do leaves decay faster?

quartzite

Erosion has stripped away the overlying rock and Seneca Rocks have been uplifted

=differential weathering