Plate Tectonics

3. breaks in the earths crust where rocks have slipped past each other to form along these boundaries
5. Any Trace of an ancient organism that has been preserved in rock.
6. Who made the hypothesis of continents plowed across the ocean floors?
11. an undersea mountain chain where new ocean floor is produced.
13. The continents drifting together to form the supercontinent
14. where two plates come together, or converge is called a
16. pieces of the earths lithosphere are in a slow, constant motion, driven by convection currents in the mantle.
17. where two plates move apart, or diverge
19. a fernlike plant that lived 250 million years ago.
20. What often occur along the transform boundaries?
21. the process by which the ocean floor sinks beneath a deep-ocean trench and back into the mantle is called

1. adds new material to the ocean floor.
2. is a place where two plates slip past each other, moving in opposite directions
4. in a process taking tens of millions of years, part of the sinks back into the mantle at deep ocean trenches
7. is a well tested concept that explains a wide range of observations
8. a deep valley
9. the ocean floor plunging into deep under water canyons called
10. a device that bounces sound waves off underwater objects and then records the echoes of these soundwaves.
12. the hypothesis that the continents slowly moved across Earth's surface.
15. the ocean floor is renewed every
18. the lithosphere broken into separate sections is called