1. Science Starter /13/15 Use the following terms to create a flow-chart of the rock cycle in your notebook:
erosion
sediments
deposition
compacting
cementation
sedimentary rock
heat
pressure
metamorphic rock
Magma
lava
melting
cooling
crystallization
intrusive igneous rock
extrusive igneous rock
weathering

2. Today’s Agenda Science Starter Weather & Erosion Introduction
Weathering Foldable
Exit Ticket

3. Lesson Essential Question
How do certain processes change rocks?
Discovery Education Video-

4. Weathering
Breakup of rock due to exposure to processes that occur at Earth’s surface
2 types:
Physical (Mechanical)- the breakdown of rock that takes place when a rock is broken into smaller pieces of the same material without changing its composition
Chemical- the breakdown or decomposition of rock that takes place when minerals are changed into different substances

5. Mechanical/Physical weathering Breaks rock into smaller units (increasing surface area) making chemical weathering faster.

6. 1. Frost wedging
Def: a process in which water freezes in the cracks of a rock and wedges it apart
Occurs when?
Where the temperature varies from below freezing to above
Mostly in porous rocks and in rocks with many cracks
Places with frequent freezes and thaws
Ice Heaving- creates potholes; ice lifts pavement up and it collapses when it thaws

7. 2. BIOLOGICAL Growth contributes Burrowing contributes
Roots wedged into tiny pores and crevices
Burrowing contributes
Animals digging holes into soil
Bringing rock fragments to surface

8. 3. Unloading/Exfoliation- the peeling of surface layers from exposed bedrock
Rock is uplifted by tectonic forces (ex: granite)
Overlying rock is worn away which reduces pressure
Upward expansion causes the granite to break along curved joints
Large sheets of loosened rock break away

9. Chemical Weathering 1. Water
Causes chemical weathering by reacting with other substances
Dissolves rock into ions & forms clay minerals
Acids: seeps into the ground and reacts chemically with many common minerals
Carbonic acid
Often breaks down limestone
underground to create caverns
Can collapse,
causing sinkholes!

10. Calcite Acid Rain Dissolves completely Underground caverns
Def: rainwater that contains unusually high amounts of acids that can be traced back to pollutants
Increases the rate of chemical weathering

11. Oxidation Chemical reaction of oxygen with other substances
Effective with minerals containing iron
Forms rust (iron oxide)
                    

12. Spheroidal Weathering

14. Rates of Weathering Weathering is usually a slow process
Factors that affect the rate of weathering:
Surface Exposure
More surface exposed, weathers more quickly
Composition of Rock
Various rocks are affected differently by weathering processes
Climate
Warm/wet climates: both chemical and mechanical
Cold/dry climates: mainly mechanical

15. DIFFERENTIAL WEATHERING

16. WEATHERING FOLDABLE!!!!

17. Weathering Foldable
You have the next 45 minutes to create a foldable on weathering
All “flaps” should have a drawing and definition
Use pg 126 (Ch 5.1) to complete the foldable (ALL INFO HERE)
The foldable will be worth 150 points and checked for a grade at the end of class
Make sure it is nicely done and complete by the end of time!

18. Directions!! You will fold along the solid black lines
You will cut along the dotted black lines
Where it says “GLUE HERE” you will apply glue and stick the 2 pieces together
If you need to see the example I will come around with my own
You may listen to music, but you must stay in your seat at ALL TIMES