Unit+1+Plate+Tectonics

2.1 Continental Drift media type="custom" key="21920870" 2.2 Seafloor Spreading media type="custom" key="21920894"

2.3 The Theory of Plate Tectonics media type="custom" key="21920874" 2.4 Tectonic Plate Boundaries media type="custom" key="21920882"