A6 University of Kansas Geological Survey. 
stones and shales and sandstones is east, approximating an angle 
the same as the inclination of the surface. In a north and south 
line there is perhaps a general inclination of the strata to the north- 
east, but the north dip is so slight that it is scarcely perceptible 
in most places. We therefore have the most favorable conditions 
for the production of broad level plains by the general weathering 
of the uplands. In most cases the valleys are simply channels cut 
into this great peneplain. 
There are irregularities in the uplands, however, which are due to 
the geologic structure and which produce very prominent features 
in the landscape. Near the eastern limit of the Dakota sandstone 
we have escarpments facing the east reaching more or less all the 
way from the north line of the state to the Arkansas river. Such 
escarpments are produced by the Dakota shales and probably the 
underlying Permian shales wearing away and the strongly cemented 
brown Dakota sandstone Serving as a protection to the upper sur- 
face. In this way a somewhat mountainous appearance is fre- 
quently produced, especially where various streams cut their way 
through the hard sandstone into the softer materials below. Plates 
V. and VI. represent two such scenes along the Union Pacific rail- 
way a few miles west of Brookville, and also Plate XXIV. at Top of 
Soldier Cap mound. Here the hard Dakota sandstone only a few 
feet thick has served as a protection to the upper part of the bluffs. 
The weathering agents have gradually removed the softer sand- 
stone and shales from beneath leaving the harder material above 
and producing a precipitous escarpment, as shown. 
The hight of such escarpments is therefore dependent upon the 
thickness of the softer material which underlies the protecting 
sandstone. If this should be 100 or 200 feet thick the escarpments 
usually have a corresponding hight. As the sandstone is traced 
towards the Arkansas river it is found that the hight of the escarp- 
ment gradually declines, until at Pawnee rock it is less than 30 feet, 
while at the north boundary of the state the hills are from 200 to 
250 feet above the surrounding plains. 
West of the Dakota sandstone area a prominent row of hills is 
found trending northeast and southwest, passing over the area 
covered by the Benton limestone. This range of hills has been 
