Geology Laboratory:

Discovering Plate Tectonics

 

"Viewed from the distance of the moon, the astonishing thing about the Earth, catching the breath, is that it is alive. Photographs show the dry, pounded surface of the moon in the foreground, dead as an old bone. Aloft, floating free beneath the moist, gleaming membrane of bright blue sky, is the rising earth, the only exuberant thing in this part of the cosmos. If you could look long enough, you would see the swirling of the great drifts of white cloud, covering and uncovering the half-hidden masses of land. And if you had been looking for a very long, geologic time, you would have seen the continents themselves in motion, drifting apart on their crustal plates, held afloat by the fire beneath."

--Lewis Thomas, from “Lives of a Cell”

 

Part A.

 

Individually, read “Continental Drift and Plate Tectonics.”  This text can be found online at:

 

http://pubs.usgs.gov/gip/dynamic/dynamic.html

 

When the reading is complete, discuss and respond to the following questions with your group.  Note:  While discussion is required, the responses should be written individually.

 

  1. Wegener’s hypothesis, known as continental drift, was based on some very good analysis of geological data from all over the world.  List and describe, in detail, the bases for his hypothesis.  Which of them do you believe to be the strongest arguments?  Why?
  2. While Wegener’s hypothesis was intelligent, interesting, and based on good evidence, there were two big questions left unanswered.  What were these major flaws that prevented the hypothesis from gaining broad acceptance?
  3. What discoveries in the following decades eventually answered the two big questions and resulted in Plate Tectonic Theory that unifies modern geology?

 

 

Part B. 

 

You will be given four maps; 3 color and one black and white.  You may draw on the black and white one only.  Each map shows data which can be used to analyze tectonic plates (seismology, volcanology, topography, and ocean floor age).  Examine each map and attempt to find the boundaries of plates.  Draw the boundaries on the black and white map of volcanoes.

 

Respond to the following:

 

  1. Describe, in detail, how each map played a part in determining the plate boundaries.
  2. List the plates that you found.  List the plates you missed.
  3. What map was the most useful?
  4. Can you use the maps to infer the direction of plate movement?  How?
  5. How many different kinds of boundaries (based on relative motion) can you find?
  6. For each boundary type, what features are present?

 

Copies of the maps can be found at the following web site:

 

http://www.geophysics.rice.edu/plateboundary/downloads.html

 

 

Reflection.

 

Finally, take a few minutes to consider what you’ve learned as a result of this lab and write a half page reflection.  You may use the following questions as a guide.

 

What aspects of this lab did you find most intriguing?  Why?  What does the history of plate tectonic theory teach you about the process of science?