Sea Floor Spreading

4. a boundary that forms when two plates come together
7. stes that pieces of the Earth's lithosphere are in slow, constant motion driven by convection currents in the mantle
8. an underwater mountain range where new sea floor is created
9. the sea floor spreads apart along both sides of a mid-ocean ridge and new crust is added
11. the process by which the ocean floor sinks beneath a deep-ocean trench
12. a boundary where two plates slip past each other moving in opposite directions
14. theory that the continents slowly moved over the Earth's surface
15. means all lands and formed the super continent in Wegener's Theory
16. the lithosphere is broken into these separate sections

1. a boundary where two plates move apart
2. breaks in the Earth's crust where the rocks have slipped past each other
3. place where the oceanic crust bends downward and sinks back into the mantle
5. a device that bounces sound waves off underwater objects and records the echoes of the sound waves
6. any trace of ancient organisms that have been preserved in rock
10. a deep valley that forms along a divergent boundary
13. a well-tested concept that explains a wide range of observations