Hi Canie. In regards to the 1865 quake I was able to find a location for it and plotted it on a map. The location I found was 37:00:00N/122:00:00W. This location shows the quake was almost in Santa Cruz and more then likely on the Ben Lomond fault. So even if it can’t be said that it was the San Andreas fault, or the Ben Lomond fault the quake occurred on it would be safe to say there was a quake.

As to the 1914 quake I haven’t been able to find the location for it. So far I haven’t found a town by the name of Laurel. The only listing for a quake near the time period was a M>6.6 a little less then 10 miles SSE of San Jose and it occurred in 1911.

The Loma Prieta quake occurred near the southern end of the 1906 quake and did occur inside the rupture zone of the 1906 quake. However as you may already know there is some discussion as to whether this quake occurred on the San Andreas fault or a parallel fault as the quake showed that it was 2/3 strike slip with 1/3 thrust which supposedly isn’t indicative of the San Andreas fault. There are some who say the Monte Vista thrust fault moved during the quake and this is where the thrust portion of the quake came from.

The Loma Prieta quake occurred in an area designated as a seismic gap by the USGS and that it was one of the most likely places for a major quake to occur. The other location designated as a seismic gap is the segment of the fault between Portola Valley and the San Francisco Peninsula.

It appears that Black Mountain has an influence on the San Andreas fault. The northern portion of the rupture from the Loma Prieta quake stopped short of Black Mountain. The southern rupture during the 1906 quake slowed or became less as it approached Black Mountain. The fault does make a little jog to the east of Black Mountain. Take Care…Don in creepy town