Plate tectonics is the geological theory that Earth's crust is made out of moving plates. Tectonic movement is thought to be caused by gravitational forces or convection currents in the Earth's mantle.PBS: Intro to Plate Tectonic Theory
Three Types of Boundaries
At convergent boundaries, tectonic plates move toward each other, causing one plate to move underneath or over top of the other. This type of boundary forms some mountain ranges and volcanoes.
Divergent boundaries occur when tectonic plates move apart from each other. This causes rifts and ridges like the Mid-Atlantic Ridge.
At transform boundaries, plates move past each other. One example of this is the San Andreas Fault.US Geological Survey (USGS)| Understanding Plate Motions
Major Tectonic Plates
- African Plate
- Antarctic Plate
- Australian- Indian Plate
- Eurasian Plate
- North American Plate
- South American Plate
- Pacific Plate
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References
Fast Facts
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Fact:
Developed as a theory in the 1960s
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Fact:
Some plate movement can cause earthquakes
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Two types of plates
continental and oceanic
