Plate tectonics

3. they move apart
6. mountains formed in part by igneous activity associated with the subduction of oceanic lithosphere beneath a continent
8. occurs when igneous rocks melt over a temp range
11. a continuous elevated zone on the floor of all the major ocean basins and varying in width from 500 to 5,000 km (300-3,000 miles)
12. a hypothesis first proposed in the 1960’s by Harry Hess
13. can widen to form a narrow sea and eventually a new ocean basin
14. a hypothesis which suggested that all present continents once existed as a single supercontinent Further, beginning about 200 million years ago
15. linear zones of irregular topography on the deep ocean floor that follows transform faults and their int active extensions
16. they slide past each other
19. a chain of volcanic islands generally located a few hundred km from a trench where there is active subduction of one oceanic plate beneath another
20. heat is continuously flowing outward from Earth’s interior causing convection in mantle
21. a narrow elongated depression of the sea floor

1. there is evidence of a glacial period dating to the locate Paleozoic era in Southern Africa South America Australia and India
2. coastlines look like they fit together like a puzzle
4. a wll tested theory proposing that Earth’s outer shell consists of individual plates that interact in various ways and thereby produce earthquakes volcanoes mountains and the crust itself
5. has a grater density than continental crust because it is mainly composed of dense ferromagnesian-rich mineral
7. they move together
9. continental crust is less likely to subduction due to its buoyancy
10. Wegener documented several cases in which the same fossil organism is found only on landmasses that are now widely separated even though it is unlikely the organism could have crossed the ocean
16. processes processes that deform Earth’s crust to create major structural features, mountains, continents, and ocean basins
17. supercontinent containing all of the existing continents
18. elevated areas of the sea floor