Evidence supporting Plate Tectonics
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1) The age of the Ocean Floor Blue is old (about 180 million years), red is very young, being less than a few million years old. As you move away from the mid-oceanic ridges, the age of the crust increases. Mid-Oceanic Ridges have been splitting the continents at a rate of about 10 cm/year, it takes 200 million years to cross the Earth, thus no oceanic crust is particularly old, all being less than 200 million years old. However, continental crust is typically 1-3 billion years old. |
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2) The Magnetic field in Oceanic Rocks When magma rises, the iron inside lines up with the current magnetic field. Once it hardens the iron is locked into that alignment. The Ocean showed a mirrored record of a changing magnetic field on Earth, meaning the ocean crust was splitting and expanding, moving the continents apart. |
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3) Rocks & Fossils The types of rocks on continents appear to be continuous across continental boundaries, for example, mountain ranges and layerings. Fossils of animals with a limited geographic range were found to be continuous across continental boundaries. For this to have happened, those continents MUST have been closer at an earlier time (even touching since these animals could not cross water). |
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4) Location of Earthquakes and Volcanism
Sites with high occurrence of earthquakes and volcanos will always
line up exactly along the plate boundaries identified above, or over
hot spots (like the Hawaiian Islands).
Approximately 200 million years ago, nearly all the continents were connected into one super continent, called PANGAEA