GRIMSLEY. | Historical Reswime. 43 
that at the base of the Permo-Carboniferous there is a well- 
marked gypsum horizon which is seen in wells at Fort Riley 
and on Clarke’s creek in Geary county. He notes the deposits 
of the Blue river, at Hope and Gypsum City, and on Mill creek, 
in Washington county, 90 feet below the Dakota sandstone. 
He also states that a hard gypsum, locally called marble, is 
found near Geuda. 
The southern Kansas gypsum deposits are described as fol- 
lows: 
‘¢There is another great gypsum horizon in Kansas. It lies high up in the 
Red Beds. Its most marked exposure is in the Gypsum Hills of Barber county. 
Its surface is partly eroded, and in such places it is from 5 to 10 feet thick; but 
where the upper Red Beds are still upon it the gypsum of the best saccharoidal 
texture is 18 feet thick. The shales of the Red Beds for a hundred feet below 
are impregnated with gypsum, glisten with selenite, and are streaked with satin 
spar. This horizon stretches away west into Comanche county, and again shows 
itself in Clark. In the Indian country it is even thicker than in Kansas. In 
lonely ravines it shows itself in the faces of perpendicular bluffs or caps the ridges 
of promontories—everywhere a great white fact to front the sun. Owing to its 
elevation and the thickness of the bed and its lack of cover, it can be worked in 
Barber county to great advantage, and Medicine Lodge has already its plaster 
factory. With increased railroad facilities a great industry will be developed, for 
the raw material is as good as any in the world, and with the experienced man- 
agement now operating, the best products of gypsum will be made here. Some 
forms of fine plaster, such as dental plaster and the kinds known as Keene’s and 
Robinson’s cements, are now successfully made, which hitherto were not supposed 
could possibly be manufactured out of England or France.”’ 
In 1892 Hay™ devoted considerable space to gypsum in his 
paper on the ‘‘ Geology and Mineral Resources of Kansas.’’ He 
placed the northern Kansas deposits in the Permo-Carbonifer- 
ous, and he was the first geologist to describe the secondary 
eypsum dirt deposits of central Kansas. In a brief paragraph 
on these deposits, he gives their origin as due to the wash of 
adjacent deposits of gypsum, clay, limestone, and sandstone. 
Classification of Cragin. 
Professor Cragin,” in a recent article on the Permian system 
in Kansas, gives an admirable description of the Medicine Lodge 
24, Eighth Biennial Report of State Board of Agriculture, pp. 8-12 and 46-48, 1891-’92. 
25. Colorado College Studies, Vol. 6, pp. 1-54, 1896. 
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