Question

In 3-5 sentences, describe how paleomagnetic evidence supports the theory that continents change position (drift) over time.(4 points)

Answer 1

When igneous and some sedimentary rocks form, magnetic minerals lock in the direction and inclination of Earth's magnetic field at that time. The recorded inclination gives a rock's paleolatitude and the declination gives its orientation, and many continents show paleomagnetic directions that differ from their present positions, implying they have moved and rotated. Apparent polar wander paths calculated for different continents only coincide if the continents are moved to their past relative positions, which supports continental drift. Complementary seafloor magnetic stripes showing symmetrical reversals about mid-ocean ridges further demonstrate seafloor spreading that drives continental movement.