Io6 • KANSAS UNIVERSnV QUARTERLY. 



the sandstone the shale is more than 200 feet thick, so that erosion 

 has produced the configuration of surface usually found in places 

 where a cap stratum of hard rook overlies a heavy bed of softer ones; 

 that is, a surface composed of broad valleys with high, steep mounds 

 and rows of hills limiting their extent. This is well illustrated by the 

 broad, level valleys of Brush creek and Shawnee creek with the irreg- 

 ular hills between them, and the isolated mounds here and there 

 adjacent to them. 



Eastward, this or a similar system of sandstone extends across the 

 state line into Missouri; but westward, it seems to gradually disap- 

 pear long before the Neosho river is reached. It would be improper, 

 therefore, to speak of it as dividing the Cherokee shales into two 

 divisions, for this is only true in places. For convenience of referenee 

 the name Coltniil>us sainisioncs will be given this sandstone system, 

 believing that it is sufiliciently well defuied in jjlaces to justify a dis- 

 tinct appellation. 



.'\t present it is imjiossible to say how many indistinct limestone 

 systems there are include<l within the Clierokee shales. The Swallow 

 limestone is moderately well defined below Oswego, but it has not 

 been traced to the east to any considerable extent. In sinking for 

 coal to the northeast of Columbus calcareous matter was usually 

 passed through, but hardly insufficient extent and purity to justify its 

 being called limestone. Still, in. places marine invertebrate fossils 

 are abundant in it. i'ossibly it is the ecpiivalent of the Swallow 

 limestone, but the two have not yet been correlated. 



The lateral extent of the Cherokee shales has never been deter- 

 mined. To the northeast they reach many miles into Missouri, and 

 to the southwest a like distance into the Indian Territory. Westward 

 and northwestward they have been reached by borings in different 

 places. At Cherryvale the city well showed that over 400 feet of 

 shale immediately overlies the Calena limestone. It is probable they 

 extend for many miles further. 



As before stated, the Cherokee shales constitute the thickest shale 

 beds known in the state. They contain the most valuable economic 

 products thus far discovered in the state, and deserve extended and 

 careful study. It is hoped that by the close of another season's field 

 work our detailed knowledge regarding them will have been greatly 

 increased. 



The Oswego limestone consists of two beds which are separated by 

 a bed of about eight or ten feet of shale. In the environs of Oswego 

 each is about ten feet thick, but westward they thicken considerably, 

 so that six miles out they are 21 and 24 feet respectively, as shown in 

 a small bore near Stover. Still farther west thev seem to unite, or 



