FAULTS OF PERRY COUNTY. F 2 . 89 



Hamilton sandstone. It begins near the east end of Maha- 

 noy ridge. Its most conspicuous effect is to throw up the 

 sandstone after it has sunk on the south side of the anti- 

 cline and so cause a repetition of its whole thickness. The 

 result of this and the Perry county faults where they cross 

 the river is in combination with the anticline to give the 

 mountain four separate summits, and to produce a tract 

 among the wildest in the county, which gradually narrows 

 eastward by the convergence of the ranges and dies away 

 at Girty's Notch on the Susquehanna. 



The throw of this fault does not exceed 600 or 700 feet, 

 and its maximum is apparently on the river. It probably 

 ranges east and west about 3 or 4 miles, but it has been im- 

 possible to trace it away from the Juniata. 



The Little Germany fault. 



This fault runs parallel to and at the distance of about a 

 mile north of the long Perry county fault. 



It develops itself near the hamlet of Little Germany in 

 Spring township and runs east northeast into Centre for 

 nearly five miles. Though far inferior in length and throw 

 to the Perry county fault it yet produces much complica- 

 tion in the geology and several noteworthy changes in the 

 topography and landscape. 



The most westerly point at which I have been able to de- 

 tect the fault is on the hill west of Little Germany, where it 

 produces a fork in the Oriskany sandstone ; one ridge con- 

 tinuing on its previous course ; the other diverges slightly 

 to the southward. The latter thrown up by the fault is 

 cut off at a short distance, the ridge terminating in a field. 



In thus bringing up the Oriskany to the surface the dis- 

 location has also brought up the Lower Helderberg lime- 

 stone adjoining it, and the result is that the limestone has 

 been quarried and burnt at one place at the distance of only 

 about one hundred feet south of and therefore apparently 

 above the Marcellus black shale, with no intervening sand- 

 stone ridge. The Marcellus thus occurs on both sides of the 

 narrow belt of limestone. 



