Across
- 7. event in which the magnetic field reverses direction
- 8. hypothesis that continents are in constant motion
- 11. naturally preserved remains, imprints, or traces of organisms
- 14. plate boundary where two plates separate
- 16. new oceanic crust forms at a mid-ocean ridge as old oceanic crust moves away
- 18. Wegener could not explain the ___________ that caused the continents to move.
- 19. plate boundary where two plates collide
- 22. mountain range located on the seafloor in the middle of the ocean
- 23. plate boundary where two plates slide by each other
- 25. force created by rising mantle of ocean ridges that creates potential for plates to move away from the ridge
Down
- 1. ancient supercontinent, composed of land that forms today’s continents
- 2. polarity of magnetic field in which magnets orient themselves to point south
- 3. sinking of a denser plate below a more buoyant plate at a convergent plate boundary
- 4. cold, rigid outermost rock layer of Earth
- 5. middle layer of Earth situated between the crust above and the core below
- 6. Alfred Wegener proposed that at one time all the continents were part of one large __________.
- 9. Continental drift is the slow ___________ of Earth’s continental plates.
- 10. polarity of today’s magnetic field; magnets orient themselves to point north
- 12. circulation of material caused by differences in temperature and density
- 13. capable of being molded or changing shape
- 15. theory that Earth’s surface is made of rock plates that move with respect to each other
- 17. Wegener noticed that the shapes of the coastlines of the continents fit together much like pieces of a ___________.
- 20. Evidence of __________ in places that are now warm supported Wegener's hypothesis.
- 21. The farther away rocks are from the mid- ocean ridge, the _________ they are.
- 24. force created by sinking of a plate, or slab, that pulls on the rest of the plate