Theory of Plate Tectonics 1) What are the types of plate boundaries and where are they located? 2)...
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Transcript of Theory of Plate Tectonics 1) What are the types of plate boundaries and where are they located? 2)...
Theory of Plate Tectonics
1) What are the types of plate boundaries and where are they located?
2) What features are found at each plate boundary.
3) How do the plates move?
Day 1: What is Plate Tectonics
• The Earth’s crust and upper mantle are broken into several movable sections called plates
• Unifying Theory of Geology. • Explains why we have mountains,
volcanoes, earthquakes, the rock cycle etc.
Plate Boundaries
There are only 3 types of plate boundaries
Divergent and Convergent Boundaries
Divergent Boundaries• Boundary between two plates
that are moving apart.
• Divergent boundaries cause
SEAFLOOR SPREADING
Boundary Type 1
Features of Divergent Boundaries
• Mid-ocean ridges• Rift valleys• Magma fills gap and causes
underwater volcanoes
Atlantic Ocean is getting BIGGER
Convergent Boundaries
• Boundaries between two plates that are colliding
• There are 3 types…
Boundary Type 2
Convergent Type 1• Ocean plate colliding with a
less dense continental plate• Subduction Zone: where the
more dense plate slides under the less dense plate
• VOLCANOES occur at subduction zones
Andes Mountains, South America
Convergent Type 2
• Ocean plate colliding with another ocean plate
• The more dense plate slides under the less dense plate creating a subduction zone called a TRENCH
Convergent Type 3
• A continental plate colliding with another continental plate
• Have Collision Zones:–a place where folded and thrust
faulted mountains form.
Transform Fault Boundaries• Boundary between two plates that
are sliding past each other• EARTHQUAKES often occur
along faults• San Andreas Fault
Boundary Type 3
San Andreas Fault, CA
Day 2: Review Questions...• What are the three types of plate
boundaries?• Draw arrows to show what
direction do plates go for each? • List two or three major features or
events that occur at each boundary?
Day 3: Causes of Plate
Tectonics
Convection Currents• The Earth’s solid Lithosphere (the crust and
upper part of the mantle) floats like a raft on the partially melted athenosphere.
• Fluid rock in the athenosphere moves toward the surface, cools, then sinks again.
• Creates convection currents beneath the plates that cause the plates to move like a conveyor belt..
Convection currents in the athenosphere cause the plates to move. Notice that divergent boundaries occur where hot material is rising and convergent boundaries occur where hot material is sinking.
Day 3: cont..
Day 3: Questions...
• What causes plates to move?• How is a convection current
formed?
Day 4: Quiz (Rockin!!!)