2 COLORADO COLLEGE STUDIES. 



not Studied till 1886, when Prof. St. John observed them, 

 describing them the following year in his "Notes on the 

 Geology of Southwestern Kansas,"* and referring them 

 doubtfully to theTriassic. 



In the past four decades geologists have repeatedly 

 shown that the passage from the Carboniferous to the Per- 

 mian system in Kansas is gradual and includes an interval 

 of so-called Permo-Carboniferous rocks which combine the 

 fauna^ of both systems. The evidence of continuity and 

 the question of the proper disposal of these intermediate 

 rocks have led to much difference of opinion, some even 

 having gone to the extreme of abandoning the Permian 

 as a system or age, merging it in the Carboniferous, in 

 attempting to avoid the difficulty of the situation. -j- The 

 Permian in America is, however, a great and widely dis- 

 tributed system, difficult of diagnosis though it often be, 

 from paucit}^ of paleontological data. It is finely devel- 

 oped in Texas, where it has great thickness and has been 

 found;]; to have occasional fossilferous horizons to within 

 less than 300 feet of its summit. 



The Permian of the Kansas-Oklahoma basin un- 

 doubtedly has many similarities to that of Texas, but it is 

 probably in only one or two of the terranes of the upper 

 Permian, especially in the Medicine Lodge gypsum, that 



*Fifth Biennial Report of the Kansas State Board of Agriculture. 



tThe upper part of what is commonly called the Devonian sys- 

 tem in America has so many of the characteristics of the Carboni- 

 ferous that so high an authority as the late Dr. Newberry treated 

 it as part of the latter system. But to place the entire Devonian 

 in the Carboniferous, or rice rers<t, on account of -its transitional 

 relation and the difficulty of assigning^ the intermediate rocks to 

 either system, would seem of questionable wisdom. The mutila- 

 tion of the standard geological column by the transfer of the Per- 

 mian to a lower than systemic rank, seems to be equally unneces- 

 sary and to serve no useful purpose, while the retention of the Per- 

 mian as a system and age in the majority of the leading geological 

 text-books and its degradation in others, is a confusion of terms of 

 which untechnical readers and students of elementary geology have 

 just cause for complaint. 



JBy the labors of Mr. W. F. Cummins. See especially his 

 "Notes on the Geology of Northwest Texas" in the Fourth Annual 

 Report of the State Geological Survey of Texas. 



