1. Plate Tectonics

2. Continental Drift
_________ proposed the theory that the crustal plates are moving over the mantle. This was supported by fossil and rock type evidence; also matching of coastline shapes.
Wegener

3. Convection Currents
Due to tremendous heat, rock in the asthenosphere (top layer of mantle) is like hot taffy
This allows plates to ride on top of hot, flowing rock.
Plates move because heat is being released from deep inside the earth.
Convection currents causes hot material to rise and expand (plates diverge) and cooler material to sink and contract (plates converge).

4. Convection Currents The force responsible for plate movement is
_ ________
convection currents

5. Plate Boundaries
The following two slides show maps of the current major plate boundaries and their relative motions.
You should be able to describe various landforms created by different plate movements.

8. Plate Boundaries Divergent Boundary – moving _____
Convergent Boundary – moving ________
Transform Fault Boundary – moving ________________________
apart
together
sideways past each other

9. Plate Boundaries
Name and draw the 3 plate boundaries using blocks with arrows showing the direction of each block’s movement.
Divergent
Convergent
Transform

10. Divergent boundary of two continental plates.
Creates a __________. Example: _____________
rift valley
East African Rift

11. Convergent boundary of two oceanic plates.
Creates an ________ and a _____. Example: _____
island arc
trench
Japan

12. Convergent boundary of an oceanic plate and a continental plate
Convergent boundary of an oceanic plate and a continental plate. Forms a _______ mountain range and a ______. Examples: _______ or _______ Mts
volcanic
trench
Andes
Cascades

13. Convergent boundary of two continental plates
Convergent boundary of two continental plates. Forms a ______ mountain range. Examples: ___________, Alps, ______________
Himalayas
folded
Appalachians

14. Transform-fault boundary where the North American and Pacific plates are moving ____ each other.
Example: ________________ in California
past
San Andreas Fault

15. Plate Boundaries Review
Places where plates move apart are called _____________ boundaries.
When continental plates diverge a ___________ is formed.
When two oceanic plates converge what is created? _________________
The Appalachians formed mainly from continental plate collisions and therefore are a __________ mountain range.
The force moving the plates is ____________ .
divergent
rift valley
an island arc and a trench
folded
Convection currents