| A | B |
|---|
| convection current | rise and fall of the matle moving the earth's plates |
| volcanoes, earthquakes, mountains | caused by convecxtion currents movint the earth's plates |
| upper mantle | supports the plates as they float |
| convergent boundary | plates collide to form mountains or subduction zones |
| divergent boundary | plates spread apart and form mid-ocean ridges and valleys |
| transform boundary | plates slide past each other and form faults |
| continental drift theory | Earth's land mass is made of plates that are constantly moving |
| Pangaea | latest supercontinent made of all earth's land mass |
| Panthalessa | super ocean at the time of Pangae |
| fossil | remains of organisms from long ago that give us clues to early life on earth |
| Caused Pangaea to break up | convection zone in the mantle |
| Laurasia and Gondwanaland | two continents formed by the breakup of Pangaea |
| Continents of Laurasia | North Anerica, Europe,. and Asia |
| Continents of Gondwanaland | Africa, Antarctica, Australia, and South America, subcontinent India |
| Pacific Ocean is becoming | smaller |
| Atlantic Ocean is becoming | larger |
| sea floor spreading | divergent plate in ocean creates new crust |
| oldest crust | farthest from the divergent boundary |
| Boundary that forms volcanoes | divergent when magma reaches the crust |
