FRA-NKLIN" COUNTY. 638 



The line of junctioa betweea the Huron and Waverly formations is 

 shown with equal distinctness at several other points. On the land 

 of E. Compton, adjoining the farm of S. R. Armstrong, in Jefferson town- 

 ship, in the valley of Black Lick, the contact of the two formations is 

 plainly to be seen. Another of these points of contact is shown in 

 Mifflin township, on the eastern bank of Big Walnut, extending through 

 several miles. Still another point, at which these facts can be studied, 

 is found in the bank of Rocky Pork, one mile east of Gahanna, and 

 thence northward for a mile. 



More than ordinary interest attaches to this boundary. It is the di- 

 viding line between two great divisions of geological time — the Devon- 

 ian and the Carboniferous. The Devonian formations were mainly deep 

 jea deposits, or, if great depth was not required for their origin, still 

 there are but few traces of shores, or of the life of the land ; but in the 

 Carboniferous, all is changed. Vast regions of the old sea floor are lifted 

 up to the level, and even above the level of the sea. We see this fact in 

 the first layers that were deposited. They are ripple marked. It is the 

 life of the land that gives interest and value to this great division. 



A brief description of the Waverly series, as shown in Franklin county 

 will now be given. It contains three well-marked element, viz., the 

 Waverly shales, ten to twenty feet in thickness, the Waverly quarry 

 system, certainly sixty feet and probably more, in thickness, and the 

 Cleveland shale of Dr. Newberry, or the Waverly black shale of Prof- 

 fessor Andrews. This last division is exposed at but one point in the 

 county, so far as known, and does not attain there a thickness of more 

 than fifteen feet. These can be shown in tabular form : 



FEET. 



(Cleveland shales 15 

 Waverly quarry system. 60 

 Waverly shales 10-20 



(a) The Waverly shales have been already briefly characterized in 

 the description of the Taylor's Station section. They consist of light 

 blue or drab, non-fossiliferous clay shales. They lack the fine lamina- 

 tion of the Huron. They weather more easily, so that the outcrop is 

 always covered with muddy waste. This division in the counties south 

 has a much greater thickness than we find here. In Ross county, it is 

 never less than sixty feet thick, and in Pike it measures ninety feet. 

 As stated above, in Franklin county, it does not exceed twenty feet, and 

 in one of the sections already named, it measures only eight feet. 



(6) The Waverly quarry courses can be seen to the best advantage 

 on the land of S. R. Armstrong, Esq., just where the Central Ohio Rail- 



