THE EARTH MOVEMENT ON THE FAULT OF APRIL 18, 1906. 97 
furrow. The movement was in the same direction as before, therefore a pulling apart of 
the pipe took place instead of a compression. There occurred two breaks in the pipe (see 
plate 594), the main one at the crossing of the fault, and the other 150 yards away on the 
northeast side of the fault, but very near it, the pipe being almost parallel with it. At 
the main break, the pipe was pulled apart 59 inches, and at the other one 21.5 inches, 
making a total displacement of 6.666 feet. The pipe was not quite parallel with the fault 
and therefore there was a slight offset, at right angles to its direction, of 4 inches at the main 
break and 2 inches at the minor one, or a total of 6 inches. <A fence which crost the fault 
at the main break is offset 6.5 feet. (Plate 60c.) 
The index map, fig. 30 (p. 95), indicates the 
position of three dislocated fences which were sur- 
veyed by R. B. Symington, C.K. The fences are 
marked A, B,C. One of these fences, C, near the 
upper end of San Andreas Lake, is nearly normal to 
the trace of the fault, and its deformation extends 
over a zone 1,200 feet wide, the total displacement 
ageregating 16.9 feet. Here, as usual, the portion on 
the southwest side of the fault moved relatively to 
the northwest, but there was a distinct drag on the 
northeast side in the same direction. (See fig. 31.) 
The offsets in three other fences southeast of San 
Andreas Lake are shown in figs. 32, 33, and 34 and 
plates 60D and 61s. é heer. 
Thruout this 2-mile stretch within which the pipe 20.3040 
line nearly parallels the fault-trace, the path of the 
latter is strongly marked by a prominent furrow in 
the sod, with the usual diagonal cracks and variable 
width. This furrow lies on the northeast side of the 



Fic. 33.— Dislocation of fence near San 
Andreas Lake, After H. Schussler. 

Scale in feet 
10 20 30 
40 50 


Fig. 34. — Dislocation of fence near San Andreas Lake. After H. Schussler. 
