Weathering of Rock

1
Weathering of Rock
Bryce National Park, UT
2
Two Types of Weathering

• Chemical weathering
• Transform rock into new substances
• Mechanical weathering
• Breaking down and reshaping rocks.

Pair share what type of rocks these are.
sedimentary
3
Chemical Cave formations carbonic acid

• CO2 H2O carbonic acid
• dissolves rock underground
• forming caves

4
Chemical Oxidation
Pair share what another name for iron oxide is
hint what color is this rock and what color does
your bicycle turn if you leave out in the rain?

• Water reacts with minerals in rock
• Water also carries O2, forming iron oxide

Monument Valley, UT
Rust
5
Chemical Acid rain

• pH is a measure of the acidity of a solution
  (liquid)
• Acids are 0-6.9, 7 is neutral, and bases are 8-14
• Pollutants from fossil fuels lower the pH to 4-5
• Damages living things, stone, and metals

1908
1969
6
Mechanical weathering

• Physical processes shape and move rocks
• Frost wedging is when water freezes then expands
  in the cracks in the rock.

7
Erosion

• The removal and transport of materials by water,
  wind, waves, ice, gravity

Ocean waves
Pair share what shaped the rock above?
8
Glaciers
Half Dome,Yosemite

• Rivers of ice rock Cut U shaped valleys

9
Wind erosion
Arches National Park, UT

• Dust carried by wind acts like a sandblaster
• Smoothes and shapes rock

10
Rate of weathering

• Some rocks erode faster than others depending on
  the minerals they are made of
• Climate effects the rate of weathering

11
Summaryuse these prompts to write your summary

• How are the 2 types of weathering different?
• What different things does weathering do to rock?
• Give examples of each type of weathering.
• Describe what makes rocks weather quickly.

12
White board Review

1. What are the two types of weathering?
2. What makes rocks like this one red?
3. What shaped this rock?

1. Chemical and Mechanical
2. Iron oxide (rust)
3. Wind carrying sand (and maybe water)