290 University of Kansas Geological Survey: 
seem to have originated from the Dakota sandstone rather than to 
belong to the Vertiary sands at the west, or the glacial sands 
farther east. 
The fossils of this formation are those of the Equus beds accord- 
ing to Dr. S. W. Williston. Those reported are:! Megalonyx, subse- 
quently described as Jf. Leydeyi, Hquus major De Kay, Spherum stri- 
atuwnm Lam., S. Suleatwum Lam., Pisidium abditum Haldeman, Ano- 
donta sp., Valvata tricarinate Say, and Gammaria sp. 
It may be well to note here the physical characteristics of the 
rocks through which the valley containing the Equus beds and the 
present valley of the Smoky Hili river are cut. The former is in 
the main cut through soft, easily eroded Permian shales. The 
northern portion has been cut through a considerable amount of 
Dakota sandstone. The 200 or more feet removed north of this is 
largely Dakota (60 feet of Permian). The section at the Smoky 
Hill buttes will give a good idea of the general nature of the rock: 
A few feet of soft sandstone at the bottom, then 110 feet of shale, 
200 feet of sandstone (now soft and friable), and a covered slope 
constitutes the section. The latter is probably sand, as the water 
percolates through it freely down to the top of the shales, where it 
breaks forth as springs. The upper part of the 200 feet is a com- 
paratively hard sandstone 10 or 12 feet in thickness. Though the 
texture of the materials in the above section may vary, and does for 
different localities, the hardness and friability remain practically 
constant, making the material admirably suited for rapid erosion. 
This is true of the entire eastern portion of Saline and McPherson 
counties. 
ORIGIN. 
Two papers have been published on this formation, one by Pro- 
fessor Udden,! the other by Professor Sharp.? The latter expresses 
the opinion that it is of glacial origin. It was thought that the ice 
formed a dam across the Kansas river somewhere below and that 
the water, backing up to Salina, burst through the divide at the 
place where the north end of this formation is situated. In evi- 
1 Udden, American Geologist, vol. VII., No. 6, June 1891. 
74 AL(OXOs) (Cit, 
3 Bulletin Kansas State Board of Agriculture, quarter ending March 13, 1894, 
19) 24) 198s Ady SIDE 
