What are the tectonic processes that cause the rocks to change or fold or fault? (igneous rock)?

Question

What are the tectonic processes that cause the rocks to change or fold or fault? (igneous rock)?

Answer 1

Geologists now understand that the process which causes the Continental Plates to move around on the surface of the earth is Plate Tectonics.  It is the primary reason why mountains are formed and earthquakes happen (Hot spot plume geologic conditions also form these features, but they are relatively rare).  As two plates collide rock is deformed and folded forming mountains (and depending on the angle of the collision, deep ocean trenches).  When this folding process causes the rock to break along a line of weakness, this causes an earthquake.  This is happening all the time, even as I write.  It has been going on since the earth first cooled down enough for a solid crust to form, and will continue for billions of years into the future.

Answer 2

To add to the above Check these references

http://geology.about.com/od/tectonicsdee...

http://pubs.usgs.gov/gip/dynamic/dynamic...