Faults

A fault is a fracture or zone of fractures between two blocks of rock.  Faults allow the blocks to move relative to each other.  This movement may occur rapidly, in the form of an eart
Earthquakes occur on faults - strike-slip earthquakes occur on strike-slip faults, normal earthquakes occur on
Earthquakes occur as a result of slip on faults in the Earths crust.  If the earthquake forms (nucleates) deep in the crust or has a magnitude below about 6, the slip on the fault may be unable to reach the surface.  Those earthquakes that occur at sha
An online map of US Quaternary Faults is available via the Quaternary Fault and Fold Database.  There is an interactive map application to view the faults online and a seperate database search f
You will have to do some research on this yourself, either in journals or books or at another web site.  A good first book reference in general for this sort of information is Stover and Coffman, (1993) Seismicity of the United States, 1568-1989 (Revis
An online map of faults which includes California can be found in the Quaternary Fault and Fold Database section of the Earthquake Hazards Program website.
The Great Valley is a basin, initially forming some ~100 million years ago as a low area between the subducting ocean plate on the west (diving down under the North American plate) and the volcanoes to the east (now the Sierra Nevada mountains).
This region of the United States has been tectonically active since the supercontinent Pangea broke up roughly 200 millon years ago, and in large part because it is close to the western boundary of the North American plate.  Since the
Faults are different from fault lines.  A fault is a three-dimensional surface within the planet Earth.
Many faults are mapped as individual segments across an area.  These fault segments are given a different value for name, number, code, or dip direction and so in the GIS database ea