Alfred Wegener had various lines of evidence supporting his Theory of Continental Drift, but many people did not take him seriously because he hadn’t provided an actual mechanism for continental movement. The proof Wegner’s theory required to become globally accepted ultimately came, not in the form of a mechanism for continental movement, but through the discovery of paleomagnetism, which affirmed that continents do in fact move. Earth’s liquid and Fe-rich outer core generates a magnetic field, the same type of magnetic field produced by a simple bar magnet (having two ends of opposite polarity). When certain minerals crystallize to form rocks, they preserve the orientation of the earth’s magnetic poles at the time of formation. In fact, the magnetic orientation of minerals within rocks is not always the same as that of the magnetic orientation of earth today! Now, you might be asking yourself why doesn’t the preserved magnetic orientation within these crystals match that of the Earth? The answer is because the continents move! Rocks on different continents have different magnetic orientations because the continents move relative to a fixed magnetic pole on earth meaning each continent has its own unique polar-wander path.