Across
- 3. reversal-When 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.
- 5. currents-a current in a fluid that results from convection.
- 6. 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.
Down
- 1. the sideways and downward movement of the edge of a plate of the earth's crust into the mantle beneath another plate.
- 2. spreading-the formation of new areas of oceanic crust, which occurs through the upwelling of magma at midocean ridges and its subsequent outward movement on either side.
- 4. drift-the gradual movement of the continents across the earth's surface through geological time.