MWJL+1.5

toc ..

The Theory of Plate Tectonics
= =

Vocabulary
= =


 * plates** - A section of the lithosphere that slowly moves over the athenosphere, carrying pieces of continental and oceanic crust.
 * scientific theory** - A well-tested concept that explains a wide range of observations.
 * plate tectonics** - The theory that pieces of Earth's lithosphere are in a constant motion, driven by convection currents in the mantle.
 * faults** - A break in Earth's crust where slabs of rock slip past each other.
 * transform boundary** - A plate boundary where two plates move/slip past each other in opposite directions.
 * divergent boundary** - A plate boundary where two plates move away from each other.
 * convergent boundary** - A plate boundary where two plates move towards each other.
 * rift valley** - A deep valley that forms where two plates move apart.( A divergent boundary)

**Outline**

 * ===The theory of plate motion===
 * Plate tectonics is the geological theory that states that that pieces of Earth's lithosphere on in a constant motion, driven by convection currents in the mantle.
 * plate can't budge without affecting the other plates surrounding it.
 * As the plates move, they collide, move, pull apart, or grind past each other, producing changes in Earth's surface.
 * These changes include:volcanos, mountain ranges, and deep-sea trenches.
 * ===Plate boundaries===
 * There are three kinds of plate boundaries.
 * Transform boundary
 * A transforrm boundary is where two plates move past each other in opposite directions.
 * Earthquakes frequently occur along these boundaries.
 * Divergent boundary
 * A divergent boundary is where two plates move away from each other.
 * Divergent boundaries occur both in the water and on the land.


 * Convergent boundary
 * A convergent boundary is where two plates move towards each other.
 * There are 3 kinds of convergent boundaries
 * When continental crust and continental crust collides.
 * Big mountain ranges form.
 * When continental crust and oceanic crust collides.
 * The oceanic crust sinks
 * When oceanic crust and oceanic crust collides.
 * The plate that is denser sinks
 * ===The continents' slow dance===
 * Plates move at slow rates.
 * From 1 to 10 cm. per year.
 * The North American plate and the Eukraisan plates are floating apart at a rate of 2.5 cm. per year.
 * That's about as fast as your fingernails grow.