2o1 
THE EASTERN PLATEAU. 
Overlying the limestones is the Devonian black shale. The region un- 
derlain by the limestones, and the easternmost edge of the Devonian black 
shale is a high gently rolling plateau, sloping very gently to the west. 
This may very properly be called the eastern plateau region of southern 
Indiana. The dip of the rocks is westward, and varies from 20 to 46 feet 
per mile. 
The Devonian limestone (corniferous) passes beneath the drainage 
near the west line of township 38 north, 8 east. 
The Devonian black shale outcrops over a strip of country some 
twelve miles wide and forms for the most part low hills and flat plains. 
Its thickness at Scottsburg is 120 feet. 
THE EASTERN LOWLAND. 
The Knobstone Group, with the Goniatite limestone overlies the De- 
vonian black shale. The base of this group is easily eroded. These easily 
eroded strata, combined with the easily eroded black shale, have been 
largely worn away, leaving the low, comparatively level country to be 
found through southern Indiana, immediately east of the Knobs and hills 
of Floyd, Clarke, Washington, Scott, Jackson, Bartholomew, and Brown 
counties. This region may properly be called the eastern lowland. 
From the eastern edge of the eastern plateau (S00 feet above tide), 
to the center of the eastern lowland (570 feet above tide at Scottsburg) 
the country slopes gently to the west, the slope corresponding almost 
exactly with the dip of the rocks. 
THE MIDDLE PLATEAU. 
The top of the Knobstone group is made up of sandstones. These 
are overlain by the Lower Carboniferous limestones. These strata resist 
the action of the weather, and consequently are directly responsible for 
the “Knobs,” which are not a range of hills, but the more or less abrupt 
eastward face of a gently westward dipping plateau, which may be 
styled the central plateau. This plateau has been deeply cut by its 
streams. 
