THE SAX FRANCISCO EARTHQUAKE 75 



Summing up, the evidence seems to warrant the following state- 

 men t s : 



1. Since the beginning of Quaternary time there have been dif- 

 ferential movements of uplift along fault planes on the San Fran- 

 cisco peninsula amounting in several cases to nearly or quite a mile 

 and one half. 



2. That these movements have been followed by subsidence and 

 subsequent uplifts, involving sliding of several hundred feet along the 

 older fault planes. 



3. That these last movements are geologically of extremely recent 

 date, that possibly a considerable part of these movements have come 

 since the occupation by the Indians, and probably have continued to 

 the present. 



4. That some of the movements along the fault planes, geologically, 

 in fairly recent times, seem to have produced more striking physio- 

 graphic results than any produced the past spring. 



5. That while the recent movement may have relieved the stress 

 which the rocks were under to such an extent that it will be many years, 

 or possibly centuries, before another such a disturbance will take place, 

 on the other hand, a comparison of the few feet of motion in April 

 with the hundreds of feet of movement that have taken place in very 

 recent time suggests that fault adjustments of equal or greater violence 

 are liable to occur at any time in the future. And since similar condi- 

 tions are known to occur all over the Pacific Coast region, no place in 

 that whole district can claim immunity. 



