94 Universtiy of Kansas Geological Survey. 
the time southern Oklahoma is reached there are probably other 
beds of gypsum, at different horizons, of as great thickness and 
prominence as the one in southern Kansas. In answer to the first 
objection it may be said that it is thought the gypsum horizon may 
be followed farther to the northeast than it is now known. The 
fact that the Cave Creek gypsum may be readily followed and 
mapped in southern Kansas and northern Oklahoma, makes it 
worthy, in the opinion of the writer, to be ranked as a formation. 
Professor Cragin divided the Cimarron series into two divisions, 
the lower of which is the Salt Fork, named from the stream of that 
name in Comanche and Barber counties and northern Oklahoma; 
and the upper, the Kiger from a creek of that name in Clark county. 
Tne Cave Creek gypsum is the upper formation of his Salt Fork 
division, so that it may be used to separate the two divisions which 
the writer regards as formations. Consequently the name of the 
lowest formation of the Cimarron series, or Red-Beds, is the Salt 
Fork, that of the middle the Cave Creek gypsum, and the highest 
formation the Kiger. The Salt Fork formation includes the Harper 
sandstone, Salt Plain measures, Cedar Hills sandstones and Flower- 
Pot shales of Professor Cragin; while in the Kiger formation are the 
I)og- Creek shales, Red Bluff sandstones, Day Creek dolomite, and 
Hackberry shales. The Big Basin sandstone which Professor 
Cragin gives as forming the top of the Kiger seems, to the writer, to 
belong in the Comanche series. This classification may be ex- 
pressed in the following table: 
Kiger formation 
Cave Creek gypsum 
Upper Cimarron 
Salt Fork formation. 
Permian ? series 
Professor Cragin has kindly informed me, in advance of publica- 
tion, of the great prominence of dolomite in the Dog Creek shales 
of central Oklahoma. From his account it is quite probable that in 
central Oklahoma this terrane is entitled to the rank of a formation 
in which case its northern extension into southern Kansas would 
have the same rank. His description is as follows: “The Dog 
Creek persists and finds great emphasis in Oklahoma, being more 
1 On some of the maps this stream is called the Nescatunga river until it unites 
with the Medicine Lodge river to form the Salt Fork in the northern part of Okla- 
homa. This name is more euphonious and has the advantage of being only one word, 
but the rule governing priority would decide in favor of retaining Salt Fork. 
