146 The American Geologist. September, 1905 
In March, 1896, professor Cragin named the Red Beds 
of Kansas, the Cimarron series, published a detailed account 
of it. which he unhesitatingly referred to the Permian sys- 
tem, and subdivided it into ten formations. t It will thus be 
seen that for some years previous to the proposal of, the 
Oklahoman series by Dr. Keyes in July, 1896, the Red Beds 
of Kansas had generally been considered by geologists as 
belonging in the Jura-Trias, the Triassic or the Permian. 
It is also evident from Dr. Keyes' original definition of 
Oklahoman that for part of the territory he had in mind 
for its upper limit the base of the true Cretaceous, so that it 
was an open question whether he intended or not to include 
in it the Red Beds. It is interesting to note in this connec- 
tion that in November, 1904, in a "Generalized geological 
section for New Mexico" Dr. Keyes gave the age of the 
^'Cimarron formation" as Triassic* although Dr. Beede more 
than three years before had shown conclusively from fossils 
that in its typical area the greater part of the Cimarron 
series is of Paleozoic age. 1 
Dr. Keyes in his paper of 1903 indicates the limits of 
the Oklahoman series in the following manner: 
"As it now appears, even according to professor Prosser's pub- 
lished data, the Oklahoman in central Kansas includes at the base 
at least one important formation more than the Big Blue series; 
and at the top at least one formation less. The Oklahoman series 
in Kansas is delimited above by the top of the Marion limestones. 
In my various papers, with one exception due to a typographical 
error arising from inability to see the proof sheets of the article, 
this fact is clearly indicated. This is particularly emphasized in 
the memoir frequently quoted by professor Prosser, on the detailed 
comparison of the Upper Carboniferous of Kansas with the Russian 
Permian."* 
It has already been shown that the basal formation of 
the Oklahoman series as defined by Dr. Keyes is the Neosho 
shale,' which is also the lowest formation of the Big Blue 
series as defined by Dr. Cragin. $ It is, therefore, clear that 
the basal limit of the Oklahoman and Big Blue series as de- 
t Col. Coll. Studies, vol. vi, pp. 1-5, 48. 
* Am. Jour. Sci., 4th ser., vol. xviii, p. 360. 
t Jour. Geol., vol. ix, July, 1901, p. 339. 
Am. Geol., vol. xxviii, July, 1901, pp. 46, 47. 
Adv. Bull. First Bien. Rept. Oklahoma Geol. Surv.. April, 1902, pp. 1-11. 
* Am. Geol., vol. xxxii, pp. 219, 220. 
t Am. Geol., vol. xxviii, 1901, p. 302. 
£ Col. Coll. Studies, vol. vi, 1896, p. 3. 
