THE PERMIAN SYSTEM IN KANSAS. 27 



branch of the Santa Fe railway. It appears again, if re- 

 membered correctly, in the lower part of the bluffs that 

 border the Beaver on its south side at the locality where 

 the Panhandle line crosses. It is not seen from that line 

 on the Canadian, though the sections given by Shumard in 

 Marcy's Red River Report make it clear that lower down 

 on the Canadian, and on both forks of Red river as well, a 

 body of similar clays lies beneath the gypsum. 



The thickness of the Flower-pot shales on the Salt 

 fork, southeast of ^tna, is in the neighborhood of 150 feet. 



THE CAVE CREEK FORMATION. 



Above the Flower-pot marls is an important gypsum- 

 bearing formation, consisting usually of either a single 

 stratum of massive gypsum or two such strata separated by 

 an interval of red clay-shale. It may be called the Cave 

 Creek gypsums, or formation, because well displayed in its 

 fuller development on Cave creek, in Comanche county, 

 Kansas. The formation appears with a similar tripartite 

 character on the north branch of Red river, as indicated by 

 Dr. George G. Shumard on Plate V of Marcy's Red River 

 Report. The lower gypsum horizon (below named and 

 described as the Medicine Lodge) is the heavier and 

 persists throughout the present known extent of the forma- 

 tion; while the upper, or Shimer (so named after the town- 

 ship through which Cave creek flows) , is less constantly 

 developed as a distinct bed of massive gypsum, not appeai*- 

 ing at all on the valley of the Medicine Lodge river, so far 

 as observed. 



At the only locality at which it has been measured, 

 viz., on Cave creek at the Comanche cave,* the formation 

 has a thickness of not less than 50 feet, of which the Medi- 

 cine Lodge gypsum occupies a thickness of 25 to 30 feet, 

 the Shimer gypsum about a third as much, and the interval 



*Named and described below, ia the account of the Medicine 

 Lodge gypsum. 



