DETAILS OF THE SECTIONS 485 



laceous shales, with occasional harder, more calcareous beds. They con- 

 tain Leperditia cf. alta, which often covers entire slabs. It is probable 

 that the dividing line between the red and the variegated shales here 

 marks the line between the Salina and Lower Monroe, or that line may 

 be some distance down in the red shales. In the western part of Perry 

 County (Saville township) this seems to be the case, as shown by the 

 following interesting section (F 2 , page 324) : 



Feet 



Solid red shale (top) 200 + 



Greenish yellow shale , 2 



Red shale and sandstone with fish scales ? 4 



Red shale and sandstone 10 



Red shale and sandstone with fish scales ? 1 



Sandy red shale 3 



Greenish yellow shale 1 



Soft red shale (almost a soft fossil ore) with Leper- 

 ditia cf . alta 3 



Red shale (base) 100 4- 



This section may mean that more than 200 feet of the red strata were 

 reworked when the Lower Monroe Sea transgressed over the old Salina 

 red sediments (Longwood), and that this amount was redeposited as 

 marine Lower Monroan. A similar thing may be indicated by the occur- 

 rence of a sandstone bed, the Bridgeport sandstone, about 200 feet below 

 the top of the red shale in Tyrone township. Though only 5 feet thick, 

 its occurrence in an otherwise uniform shale series is rather significant. 

 The "Leperditias" and fish remains may, on the other hand, indicate an 

 interruption of red sedimentation by stream or saline lake deposits. 



About 100 feet of Bossardville limestone succeed the gray shales in 

 Perry County, followed by the Clarks Mills beds, 100 to 150 feet thick. 

 These contain an abundance of fossils, all of them of Upper Monroan age 

 and of the eastern type, including Tentaculites gyrocanfhus, Spirifer 

 vanuxemi, Leperditia alta, etcetera. 



The Keefer sandstone. — What seems to be clearly the southwestern ex- 

 tension of this series of formations is seen in the post-Niagaran sand- 

 stone shales and limestones of western Maryland and adjoining districts 

 in West Virginia. The basal bed here is the Keefer sandstone, which 

 rests on Clinton, and shows the following succession of beds on the 

 Chesapeake and Ohio Canal, Maryland, at lock 53 : v: 



83 O. W. Stose and Charles Swartz : Pawpaw-Hancock Polio No. 170. T T . S. Geol. Sur- 

 vey, 1912, p. 5. 



