E. R. Schefjel 
1 66 
The statements of drillers and managers indicate that most of 
the rock formations shown in the drillings are approximately uni- 
form in thickness throughout the county; but they give varying 
statements for the “ slate (Berea^^ or Sunbury^^ Shale, probably 
including some Cuyahoga) found directly above the “Berea Sand,” 
so-called by the drillers, and underlying the drift. Assuming that 
this “slate” when laid down conformed in this particular to the 
formations beneath, pre-Pleistocene erosion would be the natural 
cause of the present irregularity in thickness. By simple computa- 
tion from records furnished, the Sinnett well is found to have a 
thickness of 184 feet of this uppermost formation, the A. R. 
Wright well 250 feet, and the Colville well 167 feet. The signifi- 
cance of this will be explained later. 
All information obtained is uniform in supporting the theory 
that the strata dip east or southeast. One manager^® stated that 
this dip equals thirty feet east per mile. Further computations 
from the three well records already quoted favor greater conserva- 
tism than this. The altitude of the upper surface of the “Berea 
Sand” (which it is assumed is uneroded and of uniform thickness 
in this area) is figured in the Sinnett well as 461 feet, in the Wright 
well 510 feet, and in the Colville well 526 feet. This dip, divided 
by the distance between the first and last, about 6 miles, gives an 
eastward slope of 19 feet per mile. The Black Hand Formation, 
the outcropping rock in this area, according to the measurements 
made by C. L. Herrick, and by Carney, shows a confirmatory dip. 
Herrick determined this dip near Granville to be 14 feet south and 
18 feet east per mile. All the data^^ secured by him indicates the 
same general direction of dip for the other formations. Carney's 
work in Perry township shows a dip eastward of nearly 13 feet, 
and southward about 18 feet per mile.^® 
Tributaries. In the outlet portion of the Raccoon several trib- 
utaries break into the north wall. The largest of these occupied 
by Clear Run entering the Raccoon just east of Mount Parnassus, 
has extended its valley ramifications northwestward into the old 
divide. The principal tributary from the south has cut a deep 
E. Orton: Geological Survey of Ohio^ voL vi, p. 371, 1888. 
Chamberlin and Salisbury: Geology ^ voL ii, p. 554, 1906. 
Fletcher S. Scott (private company), Newark, Ohio. 
Bull, Set, Lah.j Denison Univ.^ vol. iii, pp. 24--5, 1888. 
Ihtd.^ vol. xiii, p. 120, 1906. 
