continental drift
noun
mass noun
- the gradual movement of the continents across the earth's surface through geological time大陆漂移。
The reality of continental drift was confirmed in the 1960s, leading to the theory of plate tectonics. It is believed that a single supercontinent called Pangaea broke up to form Gondwana and Laurasia, which further split to form the present-day continents. South America and Africa, for example, are moving apart at a rate of a few centimetres per year.