big men L2

5. driftthe gradual movement of the continents across the earth's surface through geological time.

1. reversalsubduction the sideways and downward movement of the edge of a plate of the earth's crust into the mantle beneath another plateWhen magma rises to the Earth's surface at a mid-ocean ridge, it flows out onto both sides of the ridge, gradually cooled by the seawater.
2. current A convection current is a process that involves the movement of energy from one place to another. It is also called convection heat transfer.
3. tectonics a theory explaining the structure of the earth's crust and many associated phenomena as resulting from the interaction of rigid lithospheric plates which move slowly over the underlying mantle.
4. spreading the formation of new areas of oceanic crust,