648 GEOLOGY OF OHIO. 



3. The Waverly shales of Ross county require no extended mention. 

 They do not generally attain to the thickness which this division shows 

 in Pike cou uty, and on the western side of the county are considerahly 

 reduced. In the city of Chillicothe they measure 83.67 feet in thick- 

 ness. 



They indicate the same general history which the series elsewhere 

 shows, their surface being covered with sea-weeds, sun-cracks, and rip- 

 ple-marks. Where exposed on Stony Creek, in Franklin township, they 

 afford the finest series of ripple-marks known in the Third Geological 

 District. Similar exposures are shown in the same township, on the 

 line of Indian Creek and its tributaries. ' 



In the report on Pike county a calcareous layer of remarkable com- 

 pactness and evenness was noted as occurring near the base of the Wa- 

 verly shales, and its composition, as shown by chemical analysis, was 

 given. This same layer extends through all of the outcrop of this divi- 

 sion in Ross county. In the vicinity of Frankfort considerable account 

 is made of it as a building and flagging stone. Mr. Bergen, who made 

 the examination of this part of the county, proposes that it be recog- 

 nized as the Frankfort flag. 



4. The Waverly quarry system continues to furnish in its northward 

 extension a large supply of excellent building stone. The character of 

 the rock quarries agrees very closely in color, texture, and composition 

 with the stone derived from the typical exposures; but a very much 

 larger proportion of the series in Ross county is valueless than in the 

 district below. The stone is quite frequently found in a peculiarly 

 rough and ungainly condition, known among the quarrymen as " turtle- 

 back," or "nigger-head." In this state it has no possible uses, except as 

 protection for river banks. In all of the central regions of the county 

 the division is very much lighter than at Waverly and Jasper, being 

 frequently found to measure five to ten feet only against thirty'feet in 

 the Pike county quarries. In Paxton and Buckskin townships there is 

 a larger amount of stone again, but it is not found in as thick and valu- 

 able courses as to the southward. 



5. Ascending in the scale, we next come- to that interesting stratum, 

 the Waverly black shale. No finer exposures of this are possible than 

 are furnished in hundreds of sections through all of the central regions 

 of the county, upon both sides of the Scioto River. The greatest thick- 

 ness yet observed in this formation is found in Franklin township, near 

 the mouth of Stony Creek, where it measures not less than twenty-seven 

 feet. It is charged at this point with its characteristic fossils, Lingula 

 melia and Discina Newberryi, and the remains of fishes, often in an excel- 



