Across
- 2. one of the six or seven land masses on the globe
- 6. theory that states that Earth's crust and upper manle are broken into sections, which move around on a special layer of the mantle
- 7. a squeezing force
- 8. cycle of heating, rising, cooling, and sinking
- 12. area where an oceanic plate goes down into the mantle
- 13. a system of connected underwater mountain ranges that run throughout the world's oceans. There is a rift valley in the center of the mid-ocean ridge, where magma rises up from the mantle, and pushes out to either side, producing seafloor spreading.
- 15. boundary between two plates that are moving apart
- 17. rigid layer of Earth's surface made up of the crust and a part of the upper mantle
- 19. largest layer of Earth's surface, composed mostly of silicon, oxygen, magnesium, and iron
Down
- 1. one large landmass hypothesized to have broken apart about 200 million years ago into continents
- 2. hypothesis that continents have moved slowly to their current locations
- 3. boundary that occurs when two plates slide past one another
- 4. plastic like layer of Earth's surface below the lithosphere
- 5. Hess's theory that new seafloor os formed when magma is forced up to the surface at mid-ocean ridges
- 9. place where two plates move together
- 10. outermost layer of Earth's surface
- 11. the bending of rock layers
- 14. solid, dense center of the Earth
- 16. liquid layer of the Earth's core
- 18. a break in the Earth's crust