GLS100 LAB: PLATE TECTONICS
Discovering Plate Boundaries Part I
Physical Geology Lab I – Dr. Lindley S. Hanson
Name:__________________________________________
Specialty assigned:_____________________________
The purpose of this lab is to understand the application of various map data to
the development of the Plate Tectonics Theory, and to apply the scientific
method.
Objectives:

Locate and define plate boundaries from geographic, radiometic, seismic
and volcanic data.

Interpret sea-floor spreading and subduction from geographic, radiometic,
seismic and volcanic data.

Develop a hypothesis from a single set of data.

Explain your interpretation to others.

Evaluate and modify a hypothesis to incorporate additional data

Define the location of major tectonic plates

Identify physiographic features related to specific plate boundaries

Interpret processes occurring along different types of plate boundaries
In lecture you will learn how the theory of Plate Tectonics evolved from Wegner's
earlier hypothesis of Continental Drift as geoscientists acquired and applied new
data. In the first two labs you will use some of these data to both locate and
identify plate boundaries.
INTRODUCTION
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Plate tectonics is probably the most important unifying theory in geology. The
theory states that the Earth's rigid outer layer, the lithosphere, is broken into
several mobile plates that interact along their boundaries. Plates converge, pull
apart, and slide past one another causing a variety of features and events to
occur along their boundaries.
EXERCISE 1
Step I: Interpreting data
You will be assigned one of the specialties listed in the Table 1 and will be given a map
with data pertaining to your field. Study your map. Discuss with members of your group
the meaning of the data. Look for any linear trends or relationships that might represent
a boundary between two plates.
Specialists and Related Data
Specialist
Geochronology
Volcanology
Geography
Seismology
Map and Data
Absolute ages of rock composing the floor of the oceans. Numbers corresponding
to color key represent millions of years before present.
World distribution of volcanoes. Red dots indicate historically active volcanic
features.
Large Map: Physiographic map of the world.
Small map: Elevation in meters above and below sea level
Earthquake Locations 1990-1996 (magnitude 4 and greater). Color indicates
depth of earthquakes: red = 0-33 km, green 70 -300 km, blue 300-700
EXERCISE 2
You will each have a blank world map with the names of the major plates labeled.
However, the plates themselves are not outlined. With a pencil lightly dash the
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boundaries on the map. Then as a group discuss your hypotheses and create a group
map with boundaries clearly drawn in pencil. Correct your map and prepare yourself to
present it and your supporting hypotheses to others in the class. DO NOT DRAW
BOUNDARIES NOT SUPPORTED BY YOUR DATA!
Step 2: Reorganized into groups containing one or more specialist from each
category.
EXERCISE 3
1. Following the order given in the specialists list take turns explaining to
each other your data and your reasoning behind your placement of the
plate boundaries.
2. Once everyone understands the data presented by each specialist,
reevaluate your map. Have you drawn any hypothetical boundaries in
locations that are not supported by the other sources of data? Remember
a theory must be supported by all the data, or their must be a logical
explanation why all the data might not fit.
3. Redraw your map: Using the data from all specialists redraw all plate
boundaries on a clean world map. On the back of the map list all criteria
your group used to define the boundaries.
4. Answer the following questions:
a. Which data is the most limiting and Why?
b. Which data is a more comprehension indicator of plate boundary
locations? Why?
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c. Which data seems to locate boundaries where they don’t exist?
Step 3: Review and class discussion.
NOTES:
Step 4: Homework for next lab: Learn the name and location of each plate. You
will be quizzed on these during the next lab.
Credits: This lab has been modified from Discovering Plate Boundaries by Dale S. Sawyer,
Department of Earth Science at Rice University
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