PLATE TECTONICS KEY
1. Who proposed the theory of Continental Drift? What was his evidence?
a. Alfred Wegener
b. sea floor spreading and mid-ocean ridges
c. fossil, rock and glacial evidence
2. Who proposed the theory of Plate Tectonics? What was his evidence?
a. Harry Hess
b. magnetized rocks
3. What are ways that mountains can be formed?
a. Continental – Continental convergent plates – Himalayas and Alps
b. Oceanic-Continental convergent plates – Coastal Volcanic Mountains
4. What layer of Earth does convection currents occur?
Asthenosphere or upper mantle
5. What other words describe “convergent”?
Coming together, colliding
6. Name 3 types of convergent boundary and the geological features that the convergent boundary
forms:
a. Oceanic-Continental
1.) Coastal Volcanic Mountains – Andes Mountains
2.) Island Arcs
3.) Trenches – Peru-Chile Trench
b. Oceanic-Oceanic
1.)Trenches
2.) Volcanic Islands
3.) Island Arcs – Aleutian Islands
c. Continental-Continental
7. What happens during the process of subduction?
1.) Continental Folded Mountains – Himalayas & Alps
The denser (basalt) oceanic crust subducts under the less dense (granite) continental crust. The
oceanic crust melts as it bends into the asthenosphere layer of the earth. The extra magma
produced rises up through the earth creating volcanoes.
8. What other words describe “divergent”?
Separating, pulling apart
9. Name one geological feature that a divergent boundary forms
a. oceanic or continental rift valleys – Great Rift Valley in Africa, Mid Atlantic Ridge, and Iceland
10. Name one geological feature that a transform boundary forms
a. faults or shallow earthquakes – San Andreas Fault
11. At what type of boundary would you find the oldest ocean crust?
The oldest ocean crust can be found at an oceanic-continental convergent boundary where the
oldest crust is being subducted under the continental crust.
12. At what type of boundary would you find the youngest ocean crust?
The youngest ocean crust can be found at divergent boundary where the crust is
separating/pulling apart and magma is coming up from the asthenosphere/mantle to create
new crust.
13. What happens in the process of sea floor spreading?
In the process of sea floor spreading, the crust move apart at a divergent boundary, magma
rises from the asthenosphere to create new crust. Mid-ocean ridges are formed during this
process.
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14. Use the image above to identify the following
1. Oldest crust
2. Youngest crust
3. Convergent boundary
4. Divergent boundary
15. What is the “Ring of Fire”?
A circle found along the Pacific Ocean where volcanic activity is high therefore earning the
name “ring” of “fire (volcano)”.
16. Where does the “Ring of Fire” occur?
Pacific Ocean
17. What is plate tectonic feature creates the “Ring of Fire”?
The “Ring of Fire” occurs at a convergent oceanic-continental boundary where the oceanic crust is
subducting under the continental crust. The subducting oceanic crust as it enters the asthenosphere
then melts. The magma rises through coastal volcanoes.
TOPOGRAPHY
Using the topographic map to answer the following questions:
18. What direction is the river flowing? How do you know?
Flowing west. The “v” is pointed east.
19. Draw what the river would look like if it made a deeper canyon over time
Notice the closely spaced contour lines that the reader
that the slope is very steep.
20. Predict how a land form may be reshaped by weathering
The top of the mountain could be effected by weathering and decrease elevation
21. What identifies a steep slope on a topographic map?
Closely spaced contour lines.
22. What identifies a gentle slope on a topographic map?
Contour lines not closely spaced.
23. Using the image above draw a profile of the elevation change that occurs with the thick line: