Download Chapter 4 – Plate Tectonics

Chapter 4 – Plate Tectonics
Study Guide
Your success on the Plate Tectonics Summative Assessment depends upon
your knowledge of:
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Earth’s Layers
o Crust – Earth’s lightest material
 Oceanic is thinner and denser than continental crust
o Mantle – makes up most of Earth’s mass
o Lithosphere – crust and upper part of the mantle
 Rigid, outer-most layer
 Make up lithospheric plates
o Asthenosphere –solid rock that flows
 lithospheric plates move on this part
o Mesosphere –strong, lower part of the mantle
o Outer Core – liquid
o Inner Core – made mostly of iron
 Solid, dense center of the Earth
Convection Currents
o Occur in the asthenosphere
o Hot material from deep in the Earth rises while cooler material
near the surface sinks
o Caused by heat and gravity
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Lithospheric Plates
o Made of crust and upper part of the mantle
o Thickest part lies beneath a mountain range
o The thinnest part lies beneath the middle of the ocean
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Lithospheric Plate Boundaries
o Convergent – plates push into each other
 Cause continental mountains
o Divergent – plates move away, pull apart from each other
 Cause mid-ocean ridges
o Transform-plated slide past each other
o Slab pull
 Caused by heat and gravity
 Oceanic plate sinks and pulls the rest of the plate with it.
o Ridge push
 Caused by heat and gravity
 Oceanic plate slides down
o Has a Subduction zone
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Mountain Formation
o Folded mountains –Earth’s crust being pushed up
o Fault block mountains – sedimentary rock layers are tilted by
faulting
o Volcanic mountains
 magma reaches the Earth’s surface to form them
 Only type of mountain formed by adding new material to
the Earth’s surface.
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Theory of Plate Tectonics
o It is believed that fossils of the same land-living reptiles have
been found in Antarctica, India and South Africa because these
areas were once connected to each other.
o Plate movement measured in centimeters per year
You must answer the first question. Then choose ONE other question to
answer.
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Explain how volcanoes form.
Explain the difference between the crust and the lithosphere.
List and describe three possible driving forces of lithospheric
plate motion.
When convection takes place in the mantle, why does cooler
material sink, while warmer material rises?
If the Earth's crust is growing at mid-ocean ridges, why doesn't
the Earth itself grow larger?
Give evidence that sea-floor spreading exists.
You will be given diagrams of convergent boundaries. You will have
to identify the types of plates that are colliding and which
diagram creates the world’s tallest mountains.