Thursday, March 13, 2008

Tectonic Plate Movements


Tectonic plates shape and move the earth in many different ways. They can stretch or pull the earth in all different directions and they are reshaping the earth very slowly.

225 million years ago all the continents were combined into one big land mass called Pangaea. They very slowly began to separate because of tectonic plates moving them. From 225 million years ago till now they have been moving slowly each year because of tectonic plates separating or colliding.

There are 3 types of collisions, Continental-Continental collisions, Continental-Oceanic collisions, and Oceanic-Oceanic collisions. When two Continental plates collide they buckle and thicken which pushes the continental crust upward. When a Continental and an Oceanic plate collide the denser oceanic crust sinks into the asthenosphere. And finally when two Oceanic plates collide one of the plates with oceanic lithosphere is subducted or sinks, under the other plate.

Tectonic plates can cause many diffrent types of stress and faults. Some types of stress are compression, tension, and shearing. Compression is when two plates are pushing together. Tension is where two plates separate. And shearing is when two plates are moving past each other. Some types of faults are normal, thrust, strike-skip, and reverse.

The continents are where they are today because of tectonic plates moving and reshaping the earth. The ground we live on today is always changing and forming new things.


Anonymous said...

good facts nice research. enjoyed reading

Anonymous said...

really good facts, good information to.