Briefly outline the theory of plate tectonics and use this to describe what happens at one type of plate boundary
The theory of plate tectonics represents Earth’s outer shell divided into several plates that glide over the mantle, which is the rocky inner layer above the core. The plates act as a glide and rigid shell compared to the Earth’s mantle. The strong outer layer is called lithosphere. Where two plates join it is called a plate boundary. Plates may move towards each other at a boundary, away from each other or alongside each other. Plate boundaries can be classified in several ways. Plate boundaries where plates are moving towards each other, are called convergent, plate boundaries where plates are moving apart are called divergent and plate boundaries where plates are moving alongside each other are called transform.