Unit 4: Plate Tectonics

2. Crust that is thinner and MORE dense.
4. When tectonic plates move apart. "Di-" means "two."
5. Scientist who came up with the Continental Drift Theory.
8. Boundary between tectonic plates.
13. Theory that states the continents have moved around over time.
14. Means "Earth-ball."
16. Layer under the Asthenosphere that is hardening due to increased pressure. Means "Middle-ball."
18. Most rigid layer made of the crust and upper part of the mantle. Means "rock-ball."
19. Layer made up of oxygen, silicon, aluminum, iron, and calcium.
20. Plastic-y semisolid layer that allows for convection currents of magma. Means "Weak-ball."
21. Layer that is liquid due to iron and nickel being melted. This causes the magnetosphere.
22. Happens at convergent boundary where denser crust slides underneath less dense crust.
23. Mostly made up of iron and nickel.

1. Happens at transform boundary where plates slide across each other horizontally.
3. Deepest layer of Earth that is solid due to pressure.
6. Happens at divergent boundary where mantle cools to become new crust.
7. When tectonic plate move towards each other. "Con-" means "with."
9. Supercontinent made up of all landmasses scientists believe formed over 300 million years ago and split up over time. Means "All-land."
10. Has more magnesium and iron than the crust and has the most volume of the layers.
11. Crust that is thicker and LESS dense.
12. Theory that states that Earth's Lithosphere is divided into sever slabs/parts that glide over the Asthenosphere.
15. Study of ancient life. Means "ancient-life-study."
17. When tectonic plates slide past each other. "Trans-" means "across."