

15. SPRING TOWNSHIP. F 2 . 339 



beyond Falling spring and Warm spring (near which occurs 

 a small fold) to the high knob west of Oak Grove furnace, 

 where it crosses the line and for a short distance runs into 

 Tyrone. Returning, its course is nearly due east to the 

 township line. As it approaches this point it becomes less 

 conspicuous, apparently in consequence of thinning down. 



Along its whole outcrop in the township the Oriskany 

 perserves its usual character in the county of a hard, rough, 

 ferruginous sandstone. 



Two excellent springs of cool soft water issue on this 

 horizon at Falling spring, and contribute much to the 

 volume of water which here enters the creek. 



The Marcellus shale and limestone, (VIII.) 



The rocks of the Marcellus group are, on the whole, well 

 exposed in Spring township. They nowhere in the county 

 afford large outcrops, being thin and much covered with 

 wreckage. But on several scattered places they make an 

 appearance sufficient to show their continuity and consist- 

 ency. 



The largest exposure is near Gibson's mill where by the 

 roadside about half a mile and again about a mile north of 

 mill and along the creek, near Falling Spring, there is a fair 

 display of the harder beds of the limestone which is at the 

 last-mentioned place about 50 feet thick and contains a few 

 fragments of trilobites apparently Dalmanites. At the 

 other places above-mentioned the same fossil may be found 

 together with Atrypa reticularis. 



The Falling Spring, as it is called, is a small stream flow- 

 ing down from the north, which, reinforced by two beauti- 

 ful springs coming out of the Oriskany sandstone by the 

 roadside very near each other, falls over the face of sand- 

 stone here nearly vertical, and then reaches Sherman's creek 

 on the edges of the Marcellus limestone beds. The Mar- 

 cellus ore makes no appearance. 



Another partial but good section of the Marcellus lime- 

 stone may be seen on the road leading from Perry furnace 

 to Adam's Glen school-house where it is exposed in the cut- 



