Art. III.] Carney, Geology of Pory Township. 119 



iations of which were checked up by another instrument kept 

 at a given base in the area being worked and read hourly or 

 oftener ; that the two aneroids when kept together varied aHke 

 had been ascertained previously. 



The following formations occur in the township : 



(4) Sharon conglomerate. (2) Black Hand formation. 



(3) Logan formation. (i) Cuyahoga formation. 



In most cases the lithological distinction of the formations 

 is sufficiently marked to establish lines of contact ; whenever 

 doubt arose the question .was further investigated by seeking 

 characteristic fauna. 



1. Cuyahoga Formation. The Rocky Fork crosses the 

 northwest corner of Perry township, flowing southward through 

 Mary Ann township till within a mile of the southern bound- 

 ary where it swings eastward cutting the southwest corner of 

 Perry. Only in this latter part of its course does the stream 

 flow on rock, which is the Cuyahoga. At several points along 

 the bed are ripple marks, the best illustrations being just south 

 of the swing foot-bridge over the stream near the point of its 

 turn westward into Mary Ann township. The lower three feet 

 of section shown in Fig. i, consisting of blue shale and thin 

 sandy layers, belongs to the Cuyahoga. 



The broad valley in which Perryton lies, (Fig. 2), and the 

 valley extending south from Reform, evidently are floored in 

 the Cuyahoga. The relative great width of the former valley 

 in the region referred to is due in part to another cause consid- 

 ered later. 



2. Black Hand Formation. In the area studied the 

 maximum thickness of the Black Hand is no to 115 feet ; this 

 is attained in the southern part of the township ; the formation 

 apparently thins northward. At Haven's quarry and down 

 Quarry run southeast of Newark Professor Prosser measured 

 100 1-2 feet of Black Hand' ; one-half mile east of Claylick 

 Professor C. L. Herrick reported "about 100 feet of alternating 



'The Am. Geologist, vol. xxxiv. 1904, p. 359. 



