THE CINCINNATI GROUP 4 1 



this clay represents residual material both from the Warren lime- 

 stone and from the Richmond beds It is impossible to determine 

 from the evidence at hand. There is no doubt, however, of the 

 thinning out both of the Warren bed and of the two members of 

 the Richmond group southwestward, on approaching the southern 

 part of Hardin county, 



C. THE CINCINNATI GROUP BETWEEN THE TENNESSEE RIVER VAL- 

 LEY AND THE CENTRAL BASIN. 



It should be noticed in this connection that the Clinton also 

 thins out southwestward. At Newsom it is 30 feet thick. At 

 Centreville 20 feet of Clinton is exposed and the base is not 

 seen ; it may therefore approach 30 feet in thickness. However, 

 at Riverside, north of the railroad bridge, the thickness of the 

 Clinton is only 5 feet 9 inches, and it consists of strongly 

 cross-bedded limestone. At Dunkirk, about three miles below 

 Clifton, its thickness^ is 3 feet 9 inches. At Clifton it does not 

 exceed one foot. South of Clifton it has not been recognized. 

 If it occurs at Maddox mill, it cannot be distinguished from the 

 Osgood limestone at that point. 



5. The helpers creek Ivnestone. — About thirty-two miles north- 

 east of Riverside, along Leipers creek, Richmond limestone is 

 well exposed. It occurs two and one-fourth miles south of Fly, 

 near the top of the bluff north of the home of J. M. Gardner; 

 also a quarter of a mile north of Fly, in the bed of the creek, and 

 for some distance along the branch of Leipers creek which passes 

 the homes of Carol Litton and Tom Fox, near the old Oil Well. 

 The limestone varies from 6 to 9 feet in thickness, is coarse- 

 grained, often crinoidal, and frequently has a salmon-brown 

 color. It contains a species of Strophomena regarded by Mr. 

 Charles Schuchert as closely related to Stropho)nena Wlsconsin- 

 ensls, as far as could be determined without seeing the interiors; 

 also forms resembling Strophome?ia riigosa, and the form identi- 

 fied as Strophome?ta planodorsata. To this Richmond limestone 

 the name Leipers creek llmesto?ie^ has been given. 



Overlying the limestone is a clay shale which corresponds 



"' Silurian and Devonian Limestones of Tennessee and Kentucky," Bull. Geol. 

 Soc. ^w., Vol. XII (190 1). 



