812 WM. SIDNEY TANGIER SMITH 
while if the resultant of the movement is a depression the divide 
will migrate toward A. 
If the faulted block D’ D” E were elevated from submarine 
depths to a position similar to that of San Clemente, the final 
Dp" 
: 
A B y. E 
; Cano; 
FIG. 3. 
result of erosion would be a divide midway between the limiting 
waters on the two sides. 
The results here arrived at must be true in all cases, whether 
the movements causing faulting are slow or rapid, continuous or 
intermittent in their action, and small or great in amount. Varia- 
tion in these factors, however, will cause a variation in the rate of 
the migration, or in its extent. Other modifying factors are the 
relative positions of the divide and the line of faulting, and the 
dip of the fault-plane. 
To sum up: Where simple crustal movements occur, causing 
faulting with resultant elevation, a migration of the stream divide 
will follow, in the direction of the line of faulting when the fault- 
scarp faces the divide, away from the line of faulting when it 
does not. Or, in other words, the migration is from the axis of 
faulting when the faulted block includes the divide, and toward 
the axis of faulting when it does not. 
Wy. SIDNEY TANGIER SMITH. 
