two sub-layers of the earth's crust (lithosphere) that move, float, and sometimes fracture and whose interaction causes continental drift, earthquakes, volcanoes, mountains, and oceanic trenches.
What is a tectonic plate?
100
The crust
What is the thinnest layer?
100
North American Plate
Which plate do we live on?
200
movement of the Earth's continents relative to each other, thus appearing to "drift" across the ocean bed