1. Crustal Movement

2. Layers of The Earth Core – Center of the earth
Contains Iron and Nickel
Two Levels
Inner Core – Solid
Yes there is tremendous heat but it is out weighed by the enormous pressure which pushes the particles of Iron and Nickel so close together that they remain solid.
Outer Core – Liquid
Here heat out weighs the pressure and the Iron and Nickel are molten

3. Middle layer of the Earth
Mantle
Middle layer of the Earth
Comprised mostly of silicon, oxygen, iron, and magnesium.

4. Crust Solid and rocky outer layer of the earth
Think of the crust like an apple peel – very thin outer layer.
Types
Oceanic – Crust beneath the ocean
Comprised of silicon, oxygen, iron, and magnesium
Continental – Crust beneath the continents
Comprised mostly of silicon, oxygen, aluminum, calcium, sodium, and potassium.

5. Crust Levels Lithosphere Asthenosphere Solid topmost part of the Earth
Often considered to be the upper edge of the mantle
Made of molten material
Property of Plasticity
Able to flow or move easily

7. Activity
Draw your own version of the Earth’s Layers

8. Continental Drift Theory
Plate Tectonics
Continental Drift Theory
Alfred Wegener
1912

9. Plate Tectonics Continental Drift The Theory
All of the continents were once joined in one large land mass, Pangaea, that began breaking up and drifting apart millions of years ago
Wegener’s theory was very unpopular and rejected by most of the world’s scientists.

11. Plate Tectonics Continental Drift The Evidence
Identical types of fossils were found in Africa and South America
Many of the Earth’s rock formations line-up with formations on other continents.
Mountain ranges in African line up with matching ones in South America.
Coal fields with distinct layers in Brazil match up with identical fields in Africa

12. Plate Tectonics Continental Drift The Evidence
Glacial Deposits (Sediments and Rocks left behind by glaciers) have been found in South America, Africa, India, and Australia.
The Continental coast lines fit together like the pieces of a puzzle.

13. Plate Tectonics
Sea-Floor Spreading
Harry Hess
1960

14. Plate Tectonics Sea-Floor Spreading
Discovered a large system of underwater mountains.
Contain a deep crack
Lava erupts through these cracks pushing the ocean floor on either side away.
The lava hardens and forms new ocean floor.

15. Plate Tectonics Sea-Floor Spreading The evidence
Samples have shown that the further away from a ridge you get the older the rock.
Magnetic memory of rock material in the ocean
As magma hardens at ridges half of the rock moves in one direction and half moves in the other.
On each side the magnetic strips match the earth’s magnetic pull.

16. Plate Tectonics
Plate Tectonics
J. Tuzo Wilson

17. Plate Tectonics Plate Tectonics Plate Tectonics
The moving, irregularly shaped slabs that fit together like paving stones to form the surface layer of the earth
Tectonics
The branch of geology that deals with the movements that shape the earth’s crust

18. Plate Tectonics Plate Tectonics The Theory
The earth’s plates are in constant, slow motion, driven by convection currents in the mantle.
Do you know what convection is?
Seven Major Plates
Named for the area its surface features.
For example – The Pacific Plate
Can move up to several centimeters per year.

19. Plate Tectonics Plate Tectonics Convection
Hot material rises from the core and cool material sinks towards the core.
The cool material then heats and the rises this circular cycle causes movement.

21. Draw your own model of convection currents.
Activity
Draw your own model of convection currents.

22. Plate Tectonics Plate Tectonics Plate Boundaries
The points where plates meet.
3 Types
Divergent
Convergent
Transform or Strike-Slip

23. Plate Tectonics Plate Tectonics Divergent
Move apart at mid-ocean ridges.

24. Plate Tectonics Plate Tectonics Boundaries Convergent
Plates come together at trenches – One plate moving over top of the other.

25. Plate Tectonics Plate Tectonics Boundaries Strike-Slip
Two plates grind together and slip past each other horizontally. No new material is created and none is destroyed.

26. Fossils Geological History
Preserved remains or traces of living things
Can be used to determine age.

28. Geological Time Scale Fossils Law of Superposition
In horizontal sedimentary rock layers, the oldest rock is on the bottom

29. Geological History Fossils
How do you think Paleontologist determine the age of fossils?
Radioactive (Carbon) Dating
Determines the absolute age of rocks and fossils.
The rate at which a radioactive element decays is a constant.
Half Life

30. Geological History Fossils Index Fossils
The remains of plants and animals that existed for a relatively short period of time in a wide area.
Tell the relative age of rocks

31. Geological History Geological Time Scale
Eras – Plaeozoic, Mesozoic, Cenozoic
Periods – Eras are divided into periods.
Epochs – Only in the Cenozoic period because the information we have for this era is so much more complete.