Across
- 4. hot molten or semifluid rock erupted from a volcano or fissure,
- 5. boundary places where plates slide sideways past each other
- 6. floor spreading, the formation of new areas of oceanic crust, which occurs through the upwelling of magma at midocean ridges
- 9. drift the gradual movement of the continents across the earth's surface through geological time.
- 11. boundary occurs when two tectonic plates move away from each othe
Down
- 1. tectonics a theory explaining the structure of the earth's crust
- 2. hot fluid or semifluid material below or within the earth's crust
- 3. boundary When two plates come together
- 7. trenches long, narrow depressions on the seafloor.
- 8. big super continent
- 10. ocean ridges a long, seismically active submarine ridge system situated in the middle of an ocean basin and marking the site of the upwelling of magma