Download Weathering Outline- Standards Teacher Copy

Name: ____________________________________________
Block: __________
Earth-Environmental
Standard
WEATHERING OUTLINE (5.1)
Using section 5.1 (page 126- 132) in your text book, fill in the following outline on weathering:
1. Weathering: __decomposition of rock____________________
A. Two types
1. Mechanical: _______breaking up of rock into smaller pieces (like breaking something in
half______________________________________________________________
a. Frost wedging: __Caused by freeze and thaw . Water gets into the cracks of the
rock when it is a liquid. It then freezes and will expand… cracking the rock. Then when it is slightly
warmer, the water gets into the crack of the rock and freezes again. Example: Pot Holes
_______________________________________________________
b. Unloading: __Uplifting and Erosions. Igneous rock pushed up. It will decrease the
pressure at the surface and cause the rock to crack. Exfoliation: rock will crack off_____________________
c. Biological: _Roots, burrowing animals, worms, micro organisms… can call grow
into or break up the rock
__________________________________________________________
2. Chemical: _Tranformation od rock into one or more NEW compounds. Which change the
rocks composition: Example:rust__________________________________________________________
a. Water: Water will react chemically with the rocks
_____________________________________________________________
b. Granite: makes sand. Feldspar: will act like clay and absorb into the water. The
quarts left behind will be the sand particles and get swept away into the sea
____________________________________________________________
c. Silicates: Aluminum, Silicone, Oxygen will form clay
Sodium, Calcium, Potassium and magnesium will dissolve
___________________________________________________________
d. Spheroidal: will change the shape by dissolving the rock and rounding out the
edges
____________________________________________________________
<OVER>
B. Rates of Weathering: ___Mechanical weather will affect the chemical weathering…. The smaller the
rock particles, the more it will be weathered. Weathering is increased by increasing the surface area of the
rock… aka smaller pieces like sand will weather more than a huge chunk of rock
a. Characteristics: Mineral composition
Marble= quick
Granit is slow
_____________________________________________________________
b. Climate: water temp! the warmer the water the more it will be weathers. Hot/wet
conditions have the quickest rates of weathering. Cold= frost wedging or mechanical weathering, Dry= very
slow
_____________________________________________________________
c. Differential: Different Parts of the rock will weather at different rates
_____________________________________________________________
5.1 QUESTIONS
1. What happens to a rock’s mineral composition during mechanical weathering? It does not change
2. What is unloading? How does it contribute to weathering?. Unloading= reduces pressure that happen
when a mass of rock is exposed. The outer layer will expand, it will separate and break lose
3. How does chemical weathering affect the compounds in rock? It will transform them into a new/ different
compound
4. Name two rock characteristics and two climatic factors that affect the rate of weathering. Also describe
how these factors affect the rate of weathering.
Cracks
Mineral composition
Climate***** temp and moisture have the greatest affect on rate**** hot/wet= quick!
5. Think about the following processes: Dissolving a piece of rock salt in a pan of water and grinding a
peach pit in a garbage disposal. Which process is more like mechanical weathering and which is like
chemical weathering?
Chem= Dissolved in pan
Mechanical= peach