Besides the fit of continents, which other evidence supports plate tectonics?

• A. The periodic rise and fall of ocean tides
• B. The color of continents
• C. Paleomagnetism and sea-floor spreading also support
• D. The amount of rainfall in different continents

Answer: (C)

Paleomagnetism and sea-floor spreading provide the evidence. When new oceanic crust forms at mid-ocean ridges, the lava that cools records the Earth's magnetic field as it was at that moment. Over time the magnetic field has reversed many times, so rocks show alternating normal and reversed polarity. These magnetic stripes appear symmetrically on both sides of a ridge, clearly tracing the creation and outward movement of crust. Combined with the pattern that the youngest rocks are at the ridges and get older as you move away, this supports that new crust forms and pushes older crust apart, carrying continents with it. Tides, the color of continents, and rainfall patterns don’t reveal crust movement or crust creation, so they don’t support plate tectonics in the same way.