E. R. Schejfel 
162 
long enough, and other conditions are favorable, it will reach the 
axial line and there remain. If the axis coincides with a divide 
already established, it will hold the latter stationary unless some 
stronger influence causes it to migrate. 
‘‘If the movement is one of subsidence the divide will tend to 
migrate away from its axis; and will continue in that direction 
until the streams attain a condition of equilibrium. The migra- 
tion of the divide away from the axis of depression generally 
results in the formation of a stream along the axial line; and the 
direction in which it flows will depend, in a great measure, upon 
the pitch of the axis of the fold.’’ 
A peculiar phase of stream diversion, evidently not in the litera- 
ture but theoretically possible, may be considered. A slight dif- 
ferential movement resulting in a steepened slope on one side of 
a divide and a lessened slope on the other, would encourage head- 
water cutting on the first mentioned side and aggradation on the 
second. In time the divide would be cut through, the stronger 
stream gradually diverting the weaker by cutting back into its 
aggraded bed. Other theories have always implied a backward 
cutting through solid rock under such conditions, but the very 
movement which induces this cutting on the one side encourages 
aggradation or at least the accumulation in situ of the products 
of erosion on the other, thus giving the proposed theory a strong 
basis for support. 
Of the local movements in the United States those in the Great 
Lakes and New England areas have been given considerable 
attention. 
Tilting is probably never the only factor entering into drainage 
changes; rock structure and dip, glaciation, the revolution of the 
earth, etc., may have greater or lesser shares in the responsibility. 
DETAILED DISCUSSION OF LICKING COUNTY STREAMS ' 
Raccoon Creek. This stream will be taken as a type and a || 
minute discussion of it given to prove the change of drainage and S 
J. B. Woodworth: Bulletin 84, New York State Museum, p. 66, 1905. A. W. 1 
Grabau: Ihid., (no. 45), vol. ix, pp. 55-66, 1901. G. K. Gilbert: U. S. Geol. Surv., j 
Annual Report no. 18, pp. 601-47, 1898. G. K. Gilbert: Smithsonian Report, pp. 
237-244, 1890. Also “Preglacial Valleys of the Mississippi,” by F. Leverett, l| 
Journal of Geology, vol. iii, p. 763, 1895. I 
