Plate Techtonics

2. of Plate Tectonics a theory of global tectonics in which the lithosphere is divided into a number of crustal plates, each of which moves on the plastic asthenosphere more or less independently to collide with, slide under,or move past adjacent plates.
5. crust the relatively thin part of the earth's crust that underlies the ocean basins. It is geologically young compared with the continental crust and consists of basaltic rock overlain by sediments.
6. the sideways and downward movement of the edge of a plate of the earth's crust into the mantle beneath another plate.
7. boundary is an actively deforming region where two or more tectonic plates or fragments of the lithosphere move toward one another and collide.
9. Currents a current in a fluid that results from convection.
10. a sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action.
12. Valley a large elongated depression with steep walls formed by the downward displacement of a block of the earth's surface between nearly parallel faults or fault systems.
14. boundary are places where plates slide sideways past each other.
16. an extended break in a body of rock, marked by the relative displacement and discontinuity of strata on either side of a particular surface.

1. ranges a line of mountains connected by high ground.
3. crust the relatively thick part of the earth's crust that forms the large landmasses. It is generally older and more complex than the oceanic crust.
4. Atlantic Ridge is a mid-ocean ridge, a divergent tectonic plate or constructive plate boundary located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world.
6. Andreas Fault a continental transform fault that extends roughly 1300 km through California. It forms the tectonic boundary between the Pacific Plate and the North American Plate.
8. boundary is a linear feature that exists between two tectonic plates that are moving away from each other.
11. a long, narrow ditch.
13. a mountain or hill, typically conical, having a crater or vent through which lava, rock fragments, hot vapor, and gas are being or have been erupted from the earth's crust.
15. of fire an area in the basin of the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur.