Plate Tectonics
Across
- 4. the theory that the crust is divided into large pieces, or plates that slowly move on top of the mantle
- 5. an underwater mountain system formed by tectonic plates; largest single volcanic feature on the earth
- 7. the uppermost part of the mantle and the crust
- 12. huge piece of crust that moves slowly on the upper, ductile (soft and bendy) part of the mantle
- 16. a depression on Earth’s surface in which an ocean lies
- 17. a place where 2 tectonic plates move away from each other
- 18. a place where 2 tectonic plates come together and collide
- 19. A dark colored, extrusive igneous rock usually associated with oceanic crust
- 20. the thin, solid, outer most layer of the earth
- 21. molten material below the surface of the earth
Down
- 1. up to 80 km thick, generally makes up landmasses and is usually considered to be made of granite
- 2. molten material that has made it to the surface of the earth
- 3. the mineralized remains of organisms, showing how long dead organisms lived and how their bodies were constructed
- 6. the part of the mantle that is almost liquid, where convection currents occur
- 8. solid layer of earth between the crust and the core; made of dense silicates
- 9. the theory that continents were once connected but have since drifted apart
- 10. a phenomenon by which magma from earth’s mantle comes up to the mid-ocean ridge and creates new oceanic crust
- 11. the process in which a denser tectonic plate is pushed downward beneath a less dense plate when plates converge
- 13. A light colored, intrusive igneous rock usually found on continental crust
- 14. 5-10 km thick, generally on the bottom of the ocean floor and is usually considered to be basalt
- 15. deep and narrow depression in the sea floor where the subducted plate moves into the asthenosphere