Final answer:
Since the 1960's, the cause of plate tectonics has been identified as the movement of semi-fluid rock in the Earth's mantle, driven by heat from the Earth's interior. This generates convection currents that move the tectonic plates around the Earth's surface. The movement of these plates can cause earthquakes, volcanic activity, and the creation of mountain ranges.
Step-by-step explanation:
Since the 1960's, scientists have identified the cause of plate tectonics to be in the Earth's mantle. Specifically, it is the movement of semi-fluid rock in the Earth's mantle (asthenosphere) driven by heat from the planet's interior that is the primary cause of tectonic plate movement. This generated heat causes convection currents that move the plates around the Earth's surface.
To give some context, the Earth's surface is covered in a series of large and small tectonic plates that fit together like a jigsaw puzzle, continuously sliding over, under and past each other on the semi-fluid asthenosphere. This movement can cause a range of geological phenomena such as earthquakes, volcanic activity, and the creation of mountain ranges.
Learn more about Plate Tectonics