According to someone I worked with that had a geology background, they used to be the same rock formation. But Vasquez Rocks is on the Pacific Plate that is moving northward and Mormon Rocks is on the Continental (? not sure if I have the right plate...) plate that isn't really moving. As you know, the San Andreas Fault runs right thru the area (as well as WW). I always correct people when they say, "California is going to fall in the ocean" uh, no--San Francisco will be a suburb of Anchorage...
Well...working off my memory from my college classes and field studies....
The correct plates are the North American Plate and the Pacific Plate. The two plates converge and form the San Andres fault. They are what are considered "right lateral strike/slip fault " which means if you are standing on the North American plate and facing the Pacific plate during an earthquake you will move to the right (in a northwest direction). Same is true if you were on the Pacific plate facing the North American plate....you would move right (in a south east direction) during an earthquake.
Wrightwood is located in a transverse mountain range (San Gabriel Mountains) running in a east/west direction while the majority of mountain ranges run in a north/south direction. The mountains moved (thanks to the San Andreas fault) in a counter clockwise direction. The far east end of the range moved from the the area where the Garlock/San Andreas Fault meet. If you ever look at a raised relief map of the area where the faults meet, it looks like a large arrow pointing west.
The Vasquez rocks, Mormon Rocks and Devils Punch bowl were remnants of riverbed that were thrust up with the plate movement.
Interesting to look at the rocks up close. You can see the various layers of "sediment" from the old river beds. There are layers with large rock and layers with thin "silt". The layers with large rock would be periods of heavy rain and flooding...carrying larger rocks and sediment. The layers of fine "sand" would be from periods of light rain carrying silt down stream.
Your right about California NOT falling into the ocean. Long ago, the general belief was California was sitting on a shelf. That shelf was expected to fall off into the ocean if there was a big earth quake. They discovered that theory was not correct.
My concern would be that half of Wrightwood would end up in Mexico, the other half in San Francisco
I hear it is cheaper to live in Mexico....
