Continental Drift EES Unit 2

The Hypothesis Continental drift was proposed by Alfred Wegener in the early 1900’s The idea that all continents used to fit together into one land mass He called this Pangaea meaning “all earth”

The Evidence Animation Continents just look like they used to fit together Rocks are the same on both sides of the Atlantic Mountain ranges are the same on both sides of the Atlantic Ocean Fossils of extinct species found in different parts of the world, separated by water Evidence of glaciers near the equator Coral reefs and coal deposits found in cold climates Animation

The Final Piece Magnetic polarity was discovered to have changed over the years This is where the north pole moves over time By studying magnetite crystals in rock that started as lava

Magnetite Crystals Fresh volcanic rock points to the current north pole Older rocks the same age point to the same location, but it is not the current north pole Older rocks of different ages do not point to the same location or to the north pole

Explanations Continents did not move, but the north pole did Continents moved but the north pole did not Both the continents and the north pole moved

But……wait….. Rocks of the same age but on different continents point to different north poles Only one conclusion can be correct – both the continents and the north pole have moved This is called apparent polar wander