| A | B |
|---|
| core | innermost region of the earth |
| mantle | middle layer of the earth |
| crust | surface area of the earth that is cracked into rigid rock plates |
| pangea | a super continent that is thought to have existed about 300 yrs. ago |
| plates | make up the crust of the earth's surface |
| plate margins | boundaries between plates where the crust is being formed or destroyed |
| continental drift | theory that continents slowly move as the plates of the crust move |
| trenches | long and narrow underwater valleys |
| divergent boundaries | plates pushing apart form magma; forms mountains on land and on ocean crust |
| convergent boundaries | two plates crash into each other; land is folded or trenches are formed in the ocean |
| block mountains | sharp, very high, jagged mountains formed at convergent boundaries when the rock layers break |
| magma | molten rock found beneath the earth's surface in the mantle |
| Alfred Wegener | developed the theory of continental drifting in 1912 |
| evidence for theory of continental drifting | landforms, fossils, continents would have fit together |
