Patterns in Plate Tectonics

SWHS – UW-Geology

Record all answers and include any maps in your packet to turn in.

1. Continental Drift:

One of the first scientists to put forward a well-documented proposal for the large-scale motion of continents was a German meteorologist names Alfred Wegener. He compiled various lines of evidence supporting the hypothesis that all of Earth’s continents had been assembled as a single “supercontinent” approximately 250 million years ago. He named this supercontinent Pangaea, which is Greek for “all lands.” One piece of evidence that Wegener used was the fit of the coastlines on either side of the Atlantic.

Proceed to the following applet, read the instructions, try to fit Pangaea together and then answer the following questions:

a. Why was it difficult to piece Pangaea together?

b. What are some additional considerations (other than fit) that would be useful for your reconstruction to be more robust or accurate?

c. Did any of the present-day continents change latitude (north or south) when you made your reconstruction? Which ones?

d. What implications does a change in latitude have for the fossils you might find on these continents?

2. The Maps

Obtain the four colored maps of the world – Seismology, Volcanology, Geochronology, and Geography. Please do not write on them!

a. Take a minute to examine each map and determine what it portrays. For each map, briefly describe what data it shows and how it shows it (maybe one or two sentences each).

b. Try to determine where the 11 major plates are. Get a copy of the “Mercator Projection Map of the World” and (in pencil) take your best stab at the boundaries of these 11 major plates. You can use only the data from the four maps to guide you! When you think you’ve got it, tell your teacher. He/she will check your work and then give you the currently accepted plate boundaries map!

3. The Atlantic:

Focus your attention on the Atlantic Ocean (look at the whole thing, from Arctic to Antarctic) – particularly in the middle of the ocean basin.

a. Describe the Atlantic Ocean in terms of the four data maps. For each map, describe any patterns of the data that exist in the Atlantic – you should get a small paragraph for each map. Make sure to include the things you think is obvious!

b. Where else in the world do you see similar data patterns?

4. The west coast of South America:

Now focus your attention on the west coast of South America.

a. Describe the South American west coast in terms of the four data maps – just like you did for the Atlantic.

b. Where else in the world do you see similar data patterns?

5. The Island Arcs of Indonesia

Now look at Indonesia (the boundary between Australian and Pacific plates).

a. Describe the Indonesian Islands in the same fashion.

b. Where else in the world do you see similar data patterns?

6. The __________?

Look at your four maps and find a plate boundary area that shows a pattern that is pointedly different form the ones above.

a. Where did you choose?

b. Describe the data like you did before.

c. Where else in the world do your see similar data patterns?