Test Review Ch 5 lessons 1-3: Test Tuesday November 5th!
1. Define: Pangaea- the name of the supercontinent that existed millions of years ago, seafloor spreading – When two oceanic plates pull apart, magma rises and new crust is
formed, rift valley –a long, narrow valley that forms as tectonic plates separate,
divergent boundary – a plate boundary where two plates move away from each other,
mid-ocean ridge – a mountain range that runs along the middle of some ocean floors,
plate –the crust and lithosphere that ride on the top of the asthensophere, continental
drift – the hypothesis that he continents slowly move across Earth’s surface, fault – spot
where two plates come together, deep ocean trench – area where subduction occurs
between continental and oceanic crust, fossil – preserved remains of a plant or animal,
convergent boundary a plate boundary where two plates move toward each other,
subduction – the process by which oceanic crust sinks beneath a deep- ocean trench
and back into the mantle, transform boundary – boundary between two plates that are
sliding past each other, plate tectonics – the theory that pieces of Earth’s lithosphere
are in constant motion, driven by convection currents in the mantle
2. Explain Wegener’s theory of continental drift.
The continents were once joined together in a single landmass
3. Where would a rift valley form?
Divergent plate boundary
4. Scientists know that rocks closet to a mid ocean ridge are younger than ones farther
away. How did they discover this?
By determining the age of rock samples obtained by drilling on the sea floor
5. What causes the Earth’s plates to move? What layer are the plates located in and what
layer is the movement located?
Convection currents in the Earth’s mantle
6. Where does subduction occur? How does it happen?
Where the oceanic crust bends down toward the mantle at a deep ocean trench
7. What layer are the plates located in?
The lithosphere
8. List the evidence for sea-floor spreading.
Ocean material, magnetic stripes, and drilling samples
9. List the evidence that Pangaea once existed.
The occurrence of Glossopteris on land masses that are now separated indicate that
Pangaea once existed, puzzle piece fit of the continents, tropical plants found in arctic
climates
10.What are the longest mountain ranges on earth?
Mid ocean ridges
11.Explain the relationship between subduction and sea floor spreading.
Sea floor spreading makes new earth and subduction recycles it so the earth does not
get bigger or smaller.
12.How fast do Earth’s plates move?
very slow, only a few cm a year
13.What did scientists learn about the sea floor in the mid-1900s by using sonar? Explain.
Mid ocean ridges extend into all oceans. Most lie under thousands of meters of water,
steep sided valleys on some mid ocean ridges, form longest mountain ranges on earth.
They know all this from ocean material, magnetic stripes, and drilling samples.
14.Describe how the shapes of present day continents support the theory of continental
drift.
Land forms, mountain ranges, how the continents fit together, fossils, climate
15.Illustrate a convergent, divergent, and transform boundary.
16.Match the following attributes to the correct boundary type:
a. Oceanic crust goes under oceanic crust Convergent colliding and sinking
b. Oceanic crust collides into oceanic crust convergent colliding and crumpling
c. Oceanic crust goes under continental crust Convergent colliding and sinking
d. Continental crust slides past continental crust transform
e. Continental crust moves away from continental crust divergent
f. Continental crust moves toward continental crust convergent colliding and
crumpling
g. Mountain ranges are formed convergent colliding and crumpling
h. Volcanic activity is common divergent
i. Earthquakes are common transform
j. New crust is added divergent
k. Crust is not created or destroyed transform