Plate Tectonics

4. a fold in rock that bends upward into an arch
8. a large area of flat land elevated high above sea level
9. stress that stretches rock so that it becomes thinner in the middle
10. a huge hole left by the collapse of a volcanic mountain
11. a fold in rock that bends downward to form a valley
13. the process by which molten material adds new oceanic crust to the ocean floor
15. is a rock that usually is a light color and has a coarse texture
17. stress that pushes masses of rock in opposite directions
19. supercontinent
20. layer of rock that forms Earth's outer skin

1. a layer of hot rock in the earth's interior
2. any trace of an ancient organism that has been preserved in rock
3. an undersea mountain chain where new ocean floor is produced
5. the molten mixture of rock-forming substances, gases, and water from the mantle
6. stress that squeezes rock until it folds or breaks
7. when magma reaches the surface
12. a weak spot in the crust where molten material, or magma, comes o the surface
14. a device that records ground movement caused by seismic waves as they move through earth
16. a giant wave usually caused by an earthquake beneath the ocean floor
18. a fountain of water and steam the erupts from the ground