Ch. 4.1 (continued)

Evidence of Continental Drift (besides similarities in continental coastlines)

Fossil Evidence Identical fossils of non-swimming animals found in eastern South America and western Africa. No evidence of earlier land bridges. Many other examples.

Geologic Evidence Similar rocks and rock formations found on widely separated coastlines. Also continuation of mountain ranges. Directional evidence from ancient glaciers.

Evidence from Climate Pattern Changes. Warm weather fossil-fuel deposits (coal) found in now-cold regions, such as the eastern U.S., Siberia, and Antarctica. Means now-cold landmasses must have once been in warmer regions.

Seafloor Spreading Underwater mountain range called the Mid-Atlantic Ridge discovered in 1947. Part of an 80,000-km-long mid-ocean ridge system around the whole earth. Rocks from the ocean floor were young compared to most continental rocks.