118 KANSAS ACADEMY OF SCIENCE. 
THE CARBONIFEROUS SHALES AND LIMESTONES. 
Plate IX * is from Abilene to Kansas City, along the Kansas river. It crosses 
the limestone systems exposed in that part of the state, and represents a different 
topography from the two previous ones. The drainage systems are very old. 
The larger streams are anaclinal and the smaller ones are monoclinal. Vegeta- 
tion is abundant on upland and lowland. The streams are perennial and have 
reached their base levels. ven the small ones are filling their beds with mud. 
Valley widening has progressed to a considerable extent. Though this section 
has been exposed to the elements for a longer time than either of the others, yet 
it presents a surface nearly as rough. Its shales erode easily, it is true; yet the 
massive chert-bearing limestones resist the agencies of degradation to a wonder- 
ful degree. They dip to the west about 10 or 15 feet to the mile. Thus we have 
a system of high limestone-capped steps as we ascend the Kansas river. The 
extreme difficulty with which the arroyos corrade their channels in the heavy 
limestone prevents their being cut into outliers to any considerable extent. Asa 
consequence, the line of outcrop has a very irregular lateral lobing. 
The drainage systems here seem to have much the same outline as prior 
to the Kansas ice invasion, as their present valleys are almost coincident with 
those prior to the glacial epoch.t They would seem to be older than those 
of the western portion of the state, as the latter must be younger than the plio- 
cene deposits through which they flow, and the erosion of such extensive valleys 
in preglacial times, and in such quantities of limestone as these formations in the 
eastern part of the state contain, must have consumed a considerable time, even 
under fairly extraordinary conditions. The hills of this region are projecting 
ridges which vary from 50 to 150 feet in height. The higher are beautifully ter- 
raced, especially those on the southern tributaries of Mill creek, in Wabaunsee 
county, where the upper part of the Wabaunsee, Cottonwood and part of the 
Neosho formations are present in the same ascent. 
The climate is more moist in this than the preceding regions. The heads of 
the arroyos are more densely covered with vegetation. The agencies of degrada- 
tion have been more active, and at work longer than in either of the other re- 
gions; yet the effect on the surface outline is not very much greater. This differ- 
ence must be attributed to the combined effect of vegetation and the presence of 
the limestones, the latter of which is by far the greater, as the discussion of the 
next locality will demonstrate. 
The eastern portion of the section (IX) has been subjected to the abrading in- 
fluence of the Kansas ice invasion. It will be noticed that there is a slight re- 
duction in the surface when the glaciated region is entered near Willard; yet it 
is little more than would be expected from the natural results of ordinary ero- 
sion.{ Indeed, if it were not for the materials left by the glacier, it would be 
hard to discover that there had ever been a glacier south of the Kansas river 
west of Lawrence. 
THE PERMIAN SHALES. 
This region is in Sumner county, and the section extends from north of 
Arkansas City through Geuda Springs west to a place about eight miles north- 
west of South Haven. Here the surface rock is composed largely of Permian 
shales which erode quite easily. The long-continued action of erosion has nearly 
completed its more active work. These shales may be taken as nearly homoge- 
*From Univ. Geol. Sury. Kan., Vol. I. 
+ The valley of the Kansas river is lined in places on both sides with drift and loess, as are 
the valleys of some of the smaller streams. 
t The limestone in this section is exaggerated in order to be represented. 
