PROSSER. | The Upper Permian. 65 
necessary to say that such usage is well established in geolugical 
classification and is of decided assistance in referring briefly to 
certain local characters, or minor divisions of a formation to which 
it would be undesirable to give the rank of a formation. The classic 
state in American stratigraphic geology affords numerous illustra- 
tions of this usage as, for example, the Moscow and Ludlowville shales 
of the Hamilton formation, and the Cashaqua and Gardeau shales of 
the Portage formation. This custom seems to be sufficiently sane- 
tioned by its use in such standard works as Dana’s Manual and 
Geikies’ Text-Book of Geology. 
Five miles north of Winfield, in the southwest corner of Fair 
View township at the head of a small arroyo is an excellent exposure 
of this prominent Winfield limestone, in which the concretions are 
numerous and exactly the same in character as in this stratum 
farther north in Marion county. ‘This limestone forms a marked 
escarpment along the side of the bluff west of the Walnut river at 
Wintield where it has a thickness of 13 feet. It caps the high points 
to the east of the river at Winfield, as, for example, on the Asylum 
reservoir and College hills, where the ledge is some 80 feet higher 
than in the escarpment of the river, indicating a dip of about forty 
feet per mile to the west across the valley of the Walnut river at 
Winfield. The line of division between the Chase and Marion form- 
ations in the western part of Cowley county, follows the Walnut 
river valley for the greater part of the distance across the county. 
Apparently this same limestone is quarried on the eastern bank of 
the Walnut river east of Arkansas City, though at this locality 
above the 11 feet of massive limestone are shaly layers containing 
abundant fossils, but no concretions were seen. 
On the eastern side of the Arkansas river and canal, two and one 
half miles northwest of Arkansas -City, is a buff soft limestone, 15 
feet thick, covered by 7 feet of yellowish shales. In the limestone 
beds is a cellular layer containing specimens of Bakevellia parva, 
M. & H.—typical thin-bedded Marion limestone. 
About Geuda Springs, seven and one half miles northwest of 
Arkansas City, are outcrops of yellowish shales and coarse, cellular 
rock, some of it brownish-red to iron color—due probably to thd 
=H) 
