210 University of Kansas Geological Survey. 
county, and on Marsh creek in Jewell county. The saline properties 
of the Great Spirit spring, which is located in an outlier of the Da- 
kota near Cawker City, are due to these shales. Salt springs occur 
in this horizon in Mitchell, Jewell and Republic counties, and the 
water of the wells which pass through the shales is invariably saline. 
Gypsiferous Horizon.—Above the saliferous shales is a bed of 
shales varying in thickness from 10 to 20 feet. These shales are 
thin, laminated and of loose texture. They contain quantities of 
gypsum crystals, 
The gypsum shales are more numerous in the southern part of 
the district. Outcrops occur a few miles west of Lincoln Center, 
and near Buel, in Mitchell county. Gypsum is also found in the 
Little Timber and other mines. Above the gypsiferous shales a thin 
layer of sandstone occurs. This sandstone varies in thickness from 
8 to 12 inches and occurs in from one to six layers. In some out- 
crops the sandstone rests between thin beds of gypsum, and is very 
fossiliferous. This sandstone marks lithologically as well as paleon- 
tologically the separation of the Benton from the Dakota. 
DAKOTA STRATIGRAPHY. 
The following records of outcroppings will serve to show the 
relative positions of the different layers of the upper horizon. 
Salt Creek Section: 
Ist outcrop— 
5. Soil, 5 feet (top). 
4, Black shale with red sandstone in thin Jayers 8 feet. 
3. White sandstone 6 feet. 
2. Sand, 4 inches. 
1. Saliferous shale? (bottom). 
2d outcrop— 
5. Soil, 3 feet (top). 
4, Shale 4 feet. 
3. Sandstone 6 inches. 
2. Black shale, gypsiferous, 15 feet. 
1. Saliferous shale? (bottom). 
