PRossER.| Cretaceous.—Comanche Series of Kansas. 175 
feet below the 1800 foot line, while some five miles northwest of 
the Sun City bluff the gypsum disappears in the Medicine Lodge 
valley at an elevation of 1744, according to Professor Cragin.t 
The above shows that there is scarcely any dip to the southeast 
from Sun City for twenty miles, while from this place to the north- 
west, providing the aititudes be correct, there is a decided dip 
reaching the amount of twelve feet per mile. In reference to the 
last statement, I cannot yet say positively that there is such a 
heavy dip to the northwest. The profile section shows that Stokes 
Hill, west of Sun City, is composed entirely of Comanche, where 
it has a thickness of 165 feet; while in crossing the Tertiary prairie 
to the east branch of Sand creek, twenty four miles southwest of 
Stokes Hill, the Comanche has thinned to a mere line. On the 
northern side of Bluff creek valley the base of the Comanche is 
somewhat irregular; but it rises as it is followed somewhat to the 
south of west. This is very marked when the position of the 
Comanche in the bluff south of Bluff creek at Messing’s is compared 
with its position to the east in the creeks north of Bluff creek. 
This decided irregularity in the base of the Cretaceous in the Bluff 
creek region was first noticed by Professor St. John who said that: 
“On Sand creek, three miles northeast of Lexington, the latter 
formation appears at a level near 120 feet lower than its base on Cat 
creek, seven miles to the west.”* I am not quite sure which creeks 
were meant by Prof. St. John, but it was found that the base of 
the Comanche is approximately 140 feet higher on the creek east of 
Messing’s than it is eight miles to the southeast on the creek north- 
east of Lexington. Crossing the high prairie to the north of Ash- 
land, from Bluff creek to the Big basin, the|profile shows a small 
anticline with broad base. This corresponds with a number of 
local observations made in the high lands of central Clark county. 
The section across Mule and Walker creeks (Fig. 6) in eastern Co- 
manche county, and the Medicine Lodge river in southeastern Kiowa 
county brings out clearly the decided thickness of the Comanche in 
the high bluffs south of Walker creek, and shows the rapid thinning 
toward the north on the bluffs north of the Medicine Lodge river, as 
1 F. W. Cragin, Colorado College Studies, vol. VI, p. 31. 
2 Fifth Biennial Report Kansas State Board of Agriculture, Pt. II, p. 142. 
