630 GEOLOGY OF OHIO. 



slate, the beds already described are almost, or altogether, destitute of 

 fossils. The only organic remains found in the Waverly shales are sea- 

 weeds, and these are principally found in the uppermost layers. The 

 contents of the black slate are more varied and interesting, as has been 

 already shown; but all the rest of the series thus far reviewed is desti- 

 tute of plant or animal life. In the beds that remain to be character- 

 ized, however, both vegetable and animal fossils occur in considerable 

 abundance. The peculiar cock-tail fucoid (Spirophyton cauda-galli) begins 

 about three hundred feet above the base of the series, and is thencefor- 

 ward abundantly met with. There is one well-marked fossiliferous stra- 

 tum, in which mollusks and crinoids abound, about four hundred feet 

 above the base. This is well shown in various exposures on Chestnut's 

 Mountain, Sunfish township. It is also found in all of the ground high 

 enough to hold it to the northward, and also upon the east side of the 

 river. No quarries have been opened at this horizon, and no good oppor- 

 tunities have been found for collecting fossils. 



(2.) While shales and sandstones alternate through all the series, 

 there seems to be in Pike county less of the former element, in propor- 

 tion, above three hundred feet than below. In particular, the highest 

 beds on the west side of the Scioto, as in the caps of the knobs, are quite 

 irm in composition. They probably constitute the "Logan Sandstone" 

 of Prof. Andrews. There are known to be scattered through this upper 

 portion occasional valuable quarry courses, but they- have not been 

 worked enough to show their extent or availability. In all of the 

 higher beds, so far as noted, the color of the solid courses is darker than 

 that of the true Waverly quarries. A fawn-colored tint marks all of the 

 highest beds. 



On the east side of the river, in the central portions of the county, a 

 very similar line of facts obtains; but in the north-eastern corner, and 

 along the eastern border of the county generally, the Waverly system is 

 much reduced in thickness. In Jackson township it is not more than 

 four hundre and fifty feet in thickness. . The place of the upper beds is 

 supplied by heavy deposits of Coal-Measure conglomerate. 



5. This conglomerate is a new element in the geological scale of the 

 county. As Prof. Andrews has shown in his report upon the counties to 

 the eastward, the deposit is one of quite limited extent. It stretches in 

 a north-easterly and south-westerly direction from the west side of Jack- 

 son county into Scioto county. It occupies all of the highest ground of 

 the four following townships in Pike county, viz., Jackson, Beaver, Ma- 

 rion, and Union. In the first named township its outcrops in the hills 

 that border the Scioto valley overhang the river. It has a thickness in 



