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HEIGHT AND CHARACTER OF KNOBS, 
The knobs of the extreme southern part of Indiana do not form & 
range of hills, strictly speaking, but are the irregular eastern escarpment 
of a plateau, ranging in height from 200 to 400 feet. From the top of this 
escarpment the slope to the west is very gradual, while to the east there 
are often numerous sharp outlying hills, almost as high as the main 
plateau. 
The general course of the eastern face of the Knobstone escarpment 
from where it is cut through by the Ohio River, in township 6 S., is 
but little east of due north for about 30 miles, where, in township 1 §., 6 E.,. 
it turns to the west around the headwaters of Muddy Fork of Silver Creek. 
In the region immediately west of New Albany there are many high 
eastern outliers, which make the country very broken and rugged. A 
short distance northwest of New Albany there is a noticeable decrease in 
the number of outliers. The escarpment in this region is typical, with a 
high plateau to the west, an abrupt eastward slope with a descent of 200 
to 400 feet, and a comparatively low level country to the east. 
GENERAL CHARACTER OF THE KNOBSTONE GROUP. 
The Knobstone group in Southern Indiana is made up of a thick series. 
of clay shales, sandy shales and sandstones. The shales predominate at 
the base of the group, while the sandstones predominate at the top. The 
series of rocks was originally called the Knobstone by Owen because of 
their peculiar ‘“‘knobs,” or, as their name implies, knob-like hills that are 
often left by its erosion at a greater or less distance east of the main 
escarpment. 
Overlying the upper sandstone layers of the group are the Lower Car- 
boniferous limestones, which, with the sandstones below, form a protect- 
ing cap for the thick underlying shales. When the streams cut through 
this overlying cap of limestone and sandstone they quickly cut down 
through the underlying soft shales and form deep gorges. Because of the 
slight westward dip of the strata the eastward flowing streams always cut 
ihrongh these shale beds. 
DIP. 
The knobstones and overlying limestones dip gently to the west or 
southwest. The westward dip, in sections 1 and 2, township 3 S., 5 E.. 
was found to be 41 feet per mile. This dip is very gentle, but it is suf- 
