The Changing Earth

2. There was once a supercontinent called _____________.
3. Plates do not slide easily over each other because of _________ between them.
5. Supercontinent comprising of Australia, Antarctica, South America, Africa and India
6. The slabs of crust, soggy bottom and top layer of the mantle move as one and are called ___________ ____________.
7. A ________ _________ is when a heavier ocean plate is forced under the continental plate at an angle of 20° to 60°.
11. ___________ have formed and split apart, species have arisen and become extinct.
15. Tectonic plates and their boundaries: split, bang and ____________.
16. The layer of the earth we live on is called the ___________.
17. What new technology, used during World War II, provided new evidence for the theory of tectonic plates?
18. where plates move apart.
20. A _________ ________ conserves rock. They neither create nor destroy it.
21. where plates scrape along each other.
23. where one plate collides with another.
26. A weakened line (called a fault) in the crust causes a huge crack or _____ _____ to form.
27. The ________ is 2800 km thick. The rock here is under extreme heat and pressure and behaves like a sludgy slow-moving liquid.

1. The rocks of the ocean floor have _________ stripes, parallel with the underwater ridges.
4. Hot air and liquid rise and so will hot liquid rock, this cycle of moving rock is called a __________ __________.
8. The ______________ has changed in both its composition and its temperature.
9. _________ evidence suggests the southern continents were originally joined.
10. Supercontinent comprising of North America, Europe and most of Asia
12. Magnetic stripes indicate that the youngest rock is next to the ridges and the oldest next to the ___________.
13. ___________ has seen many changes since it was formed 4.6 billion years ago.
14. Rock is melted here and is returned to the mantle for recycling.
19. A chain of ________ often forms when ocean plate meets ocean plate.
22. Hot patches and cool patches create the convection ___________ that push the plates around.
24. _____________ result from the movement of tectonic plates.
25. ______________ and trenches come from collisions between an ocean plate and a continental plate.