UPPER PALEOZOIC FORMATIONS OF KANSAS 7 IS 



name is now adopted for this formation, but its limits are extended 

 to include the thinner bedded limestones both below and above 

 the massive Fort Riley main ledge. The Florence limestone 1 

 is apparently equivalent to the Fort Riley main ledge and the 

 name is now abandoned. 



Doyle shales. — This formation is composed of variously col- 

 ored shales with an occasional thin stratum of soft limestone, and 

 has a thickness of sixty feet. About twenty feet above the base 

 is a thin, grayish limestone which often appears on the surface, 

 and at the top are yellowish shales containing a few fossils. 

 These shales and the rocks of the overlying formations weather 

 easily and form gently undulating prairies in sharp contrast with 

 the rough topography produced by the flint and massive lime- 

 stones below. The formation is shown at various places in the 

 Doyle Creek valley to the southwest of Florence, from which 

 locality it is named the Doyle shales. 



Winfi eld formation. — This has a thickness of about twenty-five 

 feet, and is composed of a cherty limestone at the base with a 

 massive concretionary one at the top, the two separated by yel- 

 lowish shales. This chert and concretionary limestone form the 

 highest prominent chert ledge in the Kansas Permian, and make 

 a marked stratigraphic horizon that is of great assistance in 

 determining the areal geology of eastern central Kansas. The 

 chert is not so uniform in occurrence as in the Wreford and 

 Florence flints, and at some localities this horizon is repre- 

 sented simply by a prominent light gray limestone, nearly free 

 from chert. The concretions in the upper limestone are quite 

 persistent through long stretches of outcrop, although occasion- 

 ally areas are found where they are small and inconspicuous or 

 absent. As a rule, however, they are large, and the stratum may 

 readily be traced across the country either from its exposure in 

 bluffs or streams or from the line of loose reddish-brown con- 

 cretions stretching across the prairie. The irregular worn upper 

 surface of the concretionary limestone and the appearance of 

 many of the concretions, as though rolled in the mud on the 

 sea bottom, indicate a shallowing of the sea at this time, fol- 



j Jour. Geol., Vol. Ill, 1895, p. 773, No. 15 of the Chase section. 



