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definitions

tectonic plates

[(tek-ton-ik)]

The dozen or so plates that make up the surface of the Earth. Their motion is studied in the field of plate tectonics.

Note

The plates are not the same as the continents. The North American plate, for example, extends from the middle of the Atlantic Ocean to the west coast of the United States and Canada. These plates are about thirty miles thick.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.