Figure 19.
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Large mountain ranges – these are continent to continent convergences. There is never any subduction here because the crust is not dense enough. Expect metamorphic rocks here because of the pressure involved. There are no volcanoes in these regions because the crust is too thick. Large earthquakes are probable. The Appalachians are leftover mountains from when North America crashed into Eurasia.
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Massive Earthquakes – most of the massive earthquakes on earth are created by transform boundaries on continents. This explains why the worst earthquakes in North America occur in places like the San Andreas Faultline.
MEASURING PLATE MOTION It is estimated that a supercontinent like Pangea gets made and then breaks up every 500 million years. We can measure the movement of the plates to get an idea of where they are heading. This measuring system is called geodetic plate motion detection or geodesy. GPS systems above the earth are very stable and can detect the earth's
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