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8.5A Plate Tectonic Theory

8.5A Plate Tectonic Theory

Author: Sarah S

Describe the historical development of evidence that supports plate tectonic theory.

What are tectonic plates?


How has the theory of plate tectonics evolved over time as new evidence has been discovered? (Examining Wegener; Seafloor Spreading and Convections; Plate Tectonic Theory)


What were 3 key pieces of evidence Wegener used to support his theory?


What was missing from Wegener's theory?


What are convection currents and how do they relate to the current theory of plate tectonics?


Describe the 3 types of plate boundaries.

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8.9A Description and Reference Materials

The TEKS! 8.9A

"Describe the historical development of evidence that supports plate tectonic theory."


Vocab and Key Concepts

  • tectonic plates--large, solid pieces of Earth's lithosphere that move in different directions on top of a hotter, flowing layer called the asthenosphere
  • Alfred Wegener--German scientist, who, in the 1900s, proposed that  the continents were once connected into one, giant landmass known as Pangaea.


  • Sea Floor Spreading--discovery in the 1960s using WWII technology that magma is oozing up through mid-ocean ridges to creat new ocean floor  This discovery suggested that plates MOVED by convection currents in the mantle!

  • Theory of Plate Tectonics (modern day theory)--solid pieces of Earth's lithosphere move along top the asthenosphere, driven by convection currents.  A key piece of evidence is seafloor spreading.


  • Convection Currents--occur due to the fact that things that are less dense will rise/float to the top and things that are more dense will sink.  These occur anywhere there is a heat source.


Three Types of Plate Boundaries: 

                  Transform                     Divergent                  Convergent


Can you spot the different types of plate boundaries?

8.9A Material (Prezi)

Information you need to know about the theory of plate tectonics.

8.9A How Convection Currents Work (Video)

A look at how convection currents drive plate tectonics.

Intro to 8.9B

A look at several examples and models of how plate tectonics shape our world. Look for the three types of plate boundaries!

8.9A WSQ

To be completed during or after viewing the Prezi.
Please COMPLETELY fill out the form. Do not forget your name and class period.

8.9A Assignment

1. Complete the WSQ above.

2. In your journal, complete this Venn Diagram:


8.9A Tutorials Stemscopes


  • Vocab presentation, review and vocab games, practice quizzes and test questions.


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Plate Tectonics Stemscopes