182 KANSAS ACADEMY OF SCIENCE. 
at Hutchinson, Lyons, Kanopolis, and other Kansas points is from this forma- 
tion. Along the eastern outcrop of this saliferous horizon, in Cowley, Sumner, 
Sedgwick, Butler, and Harvey counties, Kansas, the water is often distinctly 
salty. In the vicinity of Geuda Springs there some small salt plains, but in com- 
parison with those referred to later in this article they are scarcely worthy the 
name. 
The Marion is succeeded above by the Wellington, and this in turn by the 
Harper.* These two formations, which approximate 1100 feet in thickness, are 
composed throughout of variously colored clays, shales, and sandstones. In the 
Wellington the clays and shales are prevailingly blue, green, or gray. In the 
Harper the color is normally a brick red. Throughout both formations there is 
a great quantity of mineral salts. Of these, gypsum and common salt predomi- 
nate, although magnesia, borax, dolomite, and others are not infrequent. These 
minerals seem to increase in amount toward the upper part of the formations. 
The salt particularly appears to reach its culmination in the Salt Plain measures 
which lie upon the Harper. 
Stratigraphically, the Salt Plain is the most unsatisfactory formation in the 
Kansas-Oklahoma Red Beds. Indeed, it is still an open question whether it 
would not be wise to either assign it to subformation rank under the Harper or 
drop it altogether from the nomenclature of the series. In discussing the forma- 
tion, Professor Cragin himself says: ‘‘ The Salt Plain measures force themselves 
upon us as a very pronounced and, if interrupted, persistently recurring saline 
horizon.’’! It is not doubted that the saliferous sandstones and shales are of 
frequent occurrence in the middle Kansas-Oklahoma Red Beds. Nor is it 
questioned that the culmination of these measures is below the Gypsum hills. 
But that all or even a greater part of these measures are confined to a definite 
horizon remains to be proven. In fact, it has been demonstrated that the largest 
salt plain in Oklahoma —the Salt Fork plain—is located near the middle of the 
Harper. 
The Salt Plain formation, as described by Cragin, outcrops along a line skirt- 
ing the east flank of the Gypsum hills, from Barber county, Kansas, as far south 
as the Canadian river. According to his last classification, it lies between the 
Harper and the Glass Mountain formations;’ the Harper comprising the large 
level area in southern Kansas and central Oklahoma, and the Glass Mountain in- 
cluding the eastern slope of the Gypsum hills. Of the four large salt plains in 
Oklahoma, at least three may be definitely assigned to this horizon. These are 
the Big Salt plain, and Little Salt plain of the Cimarron, situated in the northern 
part of Woodward county, and the Salt Creek plain, in northern Blaine county. 
The latter is located near the head of Salt creek, a tributary of the Cimarron. 
In every case these plains are situated in caiions at the base of the Gypsum 
hills, and from 150 to 200 feet below the heavy ledges of gypsum which cap these 
hills. 
Perhaps the most noted of the salt plains, from the standpoint of a historian, 
is the Big Salt plain of the Cimarron. The first white man to visit this place 
was probably Coronado, in his journey across the plains in search of the seven 
cities of Cibola. In regard to this event, Mr. J. R. Mead says: ‘‘The route or 
trail of Coronado, in his famous expedition from the Pueblos of New Mexico 
across the prairies of Kansas to the populous tribes of the Missouri, will ever 
remain an open question. The only point that we can locate with reasonable 
certainty is the salt plain of the Cimarron, just within the Kansas line —the only 
3. Colorado College Studies, vol. VI, pp. 16, 18. 
4, American Geologist, vo]. XIX, No. 5, May, 1897, p. 352. 
5. Ibid., p. 363. 
