Plate Tectonics, Volcanoes, and Boundaries

2. a "ring" of volcanoes around the Pacific Ocean where earthquakes occur.
4. a super-continent that happened about 300 million years ago when all continents were combined.
6. currents caused by convection, where hotter material rises, and cooler material sinks in a little cycle.
7. a mountain range formed in the middle of some oceans.
9. the theory explaining how Earth's plates move.
13. a chain of volcanic islands.
15. any trace of an ancient organism that is preserved in rock.
16. when mid-ocean ridges continually add new material to the ocean floor as it pulls apart.
18. how heat transfers when things are touching.
20. a break in the Earth's crust where rocks have slipped past each other.
21. how heat travels through air and space.
22. either oceanic plates or continental plates that collides.
23. where the Earth's crust pulls away in a divergent boundary on land.

1. a volcano that results as magma erupts through the crust (usually in the middle of a plate).
3. a mountain that has vents which shoots out lava, or hot gasses, or ashes.
5. when the sea floor plunges into underwater canyons. The ocean crust bends downward.
8. either oceanic plates or continental plates that pull away from each other.
10. where plates slip past one another.
11. Earth's solid outer shell that is broken into pieces.
12. process by which the ocean floor sinks beneath a deep ocean trench and back into the mantle.
14. the idea that continents moved slowly over Earth's surface.
17. a geologist and scientist who came up with the idea of continental drift.
19. measure of how much mass there is in a given volume.