Drainage Changes near Granvtlley Ohio 1 71 
ential subsidence toward the southeast. Tight has shown 
that the greater part of the Muskingum drainage system was for- 
merly connected with the Scioto system by a’ broad valley leading 
from Dresden (a few miles above Zanesville) westward past New- 
ark to the Licking reservoir^ and thence into the Scioto basin 
near Circleville.^^ The present southward course past Zanesville 
is through a much narrower valley than the old line leading west- 
ward to the Scioto Basin, and the rock floor is markedly higher 
along the present course of the Muskingum than along the old 
course/’^® This old connecting drainage line Tight has named 
the “Newark river. Besides carrying the old Muskingum 
drainage it received some of the streams now tributary to the 
Licking. 
i 2. The east bank of the old Newark river so far as observed 
; from Hanover to the Licking reservoir about 10 miles southward 
is abnormally steep considering the width of the valley. On the 
assumption that tilting has taken place this would be explained 
by an axis of uplift, approximately parallel to the valley, on the 
j further side, or a corresponding depression on the near side. 
I Under such conditions streams perpendicular to the axis also work 
j headward and may finally capture the parallel streams.^® The 
[ time required would depend on the vigor of the movement and 
the degree of intrenchment of the parallel stream sought for. 
With the case in point it is conceivable that an enormous period 
of time, representing a probably very slow movement must have 
! been required for this diversion. While the old Muskingum was 
slowly reaching back through its tributaries to the old Newark 
valley, the drainage of the latter was in turn under cutting its left 
bank in an endeavor to escape eastward. 
Conclusions. It appears from the evidence that formerly the 
drainage of the western part of Licking county passed directly to 
the valley now occupied by the Scioto System from the present 
headwater areas of the Brushy Fork, Raccoon creek and the 
I North and South Forks of the Licking. The present lower portions 
I of the same streams and also Rocky Fork (together, perhaps, with 
I glacially obliterated streams from the south) drained into the same 
Bull. Set. Lah.j Denison Univ.^ voL viii, pt. ii, pp. 35~6l, 1894. 
F. Leverett: Monograph xli, p. 155. 
^®U. S. Geological Survey, Professional Paper no. 13, plate i, 1903. 
M. R. Campbell: Journal of Geology ^ vol. iv, pp. 658-9, 1896. 
