Chapter III. 

 Description of the Formations. 



No. III. Utica and Hudson River shales. 



These shales make but small appearance in the county. 

 They are limited to a few spots on the west county line and 

 to the northwest corner, Horse Valley, where the Utica 

 shales surround its middle and most deeply eroded por- 

 tion. They are here exposed by the erosion of the Horse 

 valley and West Tuscarora anticlines, which are deeply 

 eroded between West Tuscarora and Conecocheague moun- 

 tains. This outcrop of the Utica and Hudson River shales 

 is an extension, through Path valley, of their great ex- 

 posure in the Cumberland valley. It runs southwest along 

 Path valley and rounding the end of Dividing mountain 

 joins the similar beds in Amberson's valley, and both united 

 pass into the great valley at Loudon. 



Neither of these beds has yielded with certainty any fos- 

 sils in the county. I obtained a few on the north slope of 

 Conecocheague mountain, but it is uncertain whether they 

 belong to the base of the Medina sandstone or to the top of 

 the Hudson River shales. 



No. IV. Oneida and Medina sandstone* 



This massive and hard formation is one of the most im- 

 portant in the county, making all the mountains except 

 those formed by the Pocono sandstone. 



The Medina rises around three sides of the county, north, 

 west, and south, as an almost unbroken fortification, from 

 the Juniata river above Millerstown to the Susquehanna 



*The Oneida (TV a) well developed further north is not distinguishable 



here. The Medina lVb,IV c. 



(43 F\) 



