Plate Tectonics

2. primary driving force for movement of tectonic plates, heating and cooling of material in mantle
3. elevated area of the seafloor characterized by high heat flow & volcanism
8. individual pieces of Earth’s shell that interact to produce earthquakes, volcanoes, etc.
9. formed during continental-continental convergence; composed of deformed sedimentary and metamorphic rocks; ex. The Himalayas
11. Older, denser portions of oceanic lithosphere that descend into mantle at a rate equal to seafloor production
13. deep canyonlike structure along the crest of some ridge segments
14. Lithosphere stretches, promotes mantle upwelling, thins lithosphere and breaks brittle crystal rocks, broken fragments sink generating an elongated depression
15. theory that new oceanic crust is produced at the crests of mid-ocean ridges
16. a plate boundary in which two plates move apart
18. one descends beneath the other, initiating volcanic activity; produces volcanic island arcs
19. crust folds and deforms the accumulation of sediments and sedimentary rocks along the continental margin; produces mountain belts
20. a narrow, elongated depression of the seafloor

1. the buoyant continental crust remains “floating” while the denser oceanic crust sinks into the mantle; forms continental volcanic arcs
4. 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
5. linear zone of irregular topography on the deep-ocean floor that follows transform faults and their inactive extensions
6. a plate boundary in which two plates slide past one another without creating or destroying lithosphere
7. the theory that there was once a supercontinent and over time it broke into smaller continents which drifted to their present positions
10. mountains formed in part by igneous activity associated w/ the subduction of oceanic lithosphere beneath a continent
12. supports Continental drift theory, ancient climates, coastlines, matching fossils, etc.
17. a plate boundary in which two plates move toward one another