Plate Tectonics

5. A plate boundary where two plates move away from each other
8. A plate boundary where two plates move toward each other
9. The theory that pieces of Earth's lithosphere are in constant motion driven by convection currents in the mantle
12. The name of the single landmass that began to break apart 200 million years ago and gave rise to today's continents
13. A break in Earth's crust along which rocks move
14. A section of the lithosphere that slowly moves over the asthenosphere carrying pieces of continental and oceanic crust
15. Rock formations that result from molten material erupting underwater and rapidly cooling
16. A plate boundary where two plates slide past each other in opposite directions

1. The hypothesis that the continents slowly move across Earth's surface
2. The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary
3. An undersea mountain chain where new ocean floor is produced; a divergent plate boundary under the ocean
4. The scientist who proposed the hypothesis of continental drift
6. A deep valley along the ocean floor beneath which oceanic crust slowly sinks toward the mantle
7. A deep valley that forms where two plates move apart
10. A device used to map the ocean floor
11. The process by which molten material adds new oceanic crust to the ocean floor
13. The preserved remains or traces of an organism that lived in the past
16. A scientist who mapped parts of the ocean floor in the 1950s