CLASSIFICATION OF UPPER PALAZOZOIC ROCKS. 781 
quite universally considered as Permian. As previously stated, 
the Marion flint and concretionary limestone form a horizon 
which is readily traced in the field, as well as a clearly marked 
stratigraphic line, so that it is well adapted to serve as the line 
of separation between two formations. In fact it is the only 
sharply defined stratigraphic line in this part of the series, and 
such a classification is further supported by the almost entire dis- 
appearance of Brachiopods, although a few specimens continue 
somewhat higher in accordance with similar facts noted in refer- 
ence to other formations. 
Comparison of the Chase formation with Swallow’s section — 
It is perfectly clear from a comparison of the sections that the 
horizon termed the Strong flint in the Chase formation comprises 
beds No 62-58 inclusive of Swallow, to which he gave a thick- 
ness varying from thirty-six to sixty-three feet, and which is 
called forty-two feet in the Chase formation. The flint stratum 
at the base of the Chase formation, No. 1 of the section, equals 
No. 62 of Swallow’s list which he called the ‘fifth cherty lime- 
stone” and described as ‘‘a light drab and buff cherty magnesian 
limestone,’ twelve feet’? containing ‘‘ Productus Calhountanus, 
Chonetes mucronata, Orthisina like umbraculum, Athyrts like subtilita 
and Crinoids,”’ near Fort Riley.* Swallow called his bed No. 58 
the “fourth cherty limestone” which corresponds to No 4 of the 
Strong flint, and he assigned it a thickness varying from ten to 
twenty-four feet. 
The Florence flint represents bed No. 54 of Swallow, the 
“third cherty limestone’ which he described as “light buff and 
magnesian, forty feet” containing “ Productus Calhounianus, Orthi- 
*The following analysis by Mr. Warren Finney shows that it is not a magnesian 
limestone. 
SiO. - - - 03.01 per cent. 
ALO, = - - - = eTyie7/2 cs 
CaCO, - - - - SO.35 
MgCo, - - - = (ies -— % 
Fe20; - - - - maces © 
101.09 ss 
CO - - > - Hoa 
? Prel. Rep. Geol. Surv., Kansas, p. 14. 
