48 University Geological Survey of Kansas. 
The gypsum in thecentral area lies higher in the Permian, in 
the Marion shales and limestones, which are covered by the red 
Dakota sandstone, as does also that to the southeast in the 
vicinity of Mulvane and Geuda Springs. 
In the southern or Medicine Lodge area the gypsum is found 
in the red, sandy shales of the Red Beds, which are probably 
Upper Permian. There is no break or unconformity between 
them and the lower lying Permian, and they are covered uncon- 
formably either by Cretaceous strata, or by Tertiary gravels. 
The deposits of gypsum, therefore, rise geologically from north 
to south, but they are confined to the Permian formation. The 
deposits to the south in Indian Territory, Oklahoma, and Texas, 
have been placed in the Permian, while those at the north in 
Iowa are referred to the Cretaceous. 
STRATIGRAPHICAL RELATIONS. 
Northern Gypsum Area.—The gypsum deposits of northern 
Kansas rest on a nearly level floor of limestone which dips to- 
ward the west atalow angle. The gypsum stratum is solid and 
not laminated, and it is traversed by irregular branching clay 
seams. The upper surface of the gypsum is very irregular, 
showing that much of it has been removed since its first forma- 
tion. This was done before the consolidation of the overlying 
shales, for they are horizontal and are not folded to conform to | 
the irregularities. This uneven surface is shown in all the 
mines, but perhaps best in the Great Western mine, where the 
gypsum for 200 feet lies in rounded masses with the long direc- 
tion parallel to the hill slope. 
The water channels so well shown in the Winter mine, and 
the cutters or veins with their beautiful transparent crystals in 
the Fowler mine, show that water solution has produced marked 
effects in the later history of the deposits, effects which are even 
now in operation. The underground circulating waters have 
dissolved the gypsum, forming channels, and have redeposited 
much of the substance in the fissure in the form of transparent 
crystals, or near the top in the form of needles of satin spar. 
A glance at the map of the area shows that a very large quan- 
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