in the Cayuga Lake Region. 233 



less than 1° northward for about a mile, when they 

 assume approximately a horizontal position for another 

 mile or so, before again dipping to the north at a rather 

 higher angle than before. This is again followed by a 

 horizontal area at Ludlowville. A short distance north- 

 west of the boundary of the accompanying map the dip 

 is reversed and the beds continue a southerly dip to the 

 northern end of the lake, some thirty miles distant. 



The major fold will here be spoken of as the Portland 

 Point anticline, from the present name of the point, though 

 it was formerly known as Shurger's Point and is so 

 named on the topographic sheet. Its axis across Cayuga 

 Lake trends nearly 5° south of E-W with a westerly pitch 

 of about 44' per mile, that is, about Mj . This westward 

 pitch of the anticline combined with the general southerly 

 dip of the strata serves to give an ever increasing height 

 to the strata in a northeasterly direction. 



Faults in the Encrinal limestone. 



Faulting, like the other dynamic movements of the 

 region, is on an unobtrusive scale and would deserve little 

 or no attention were it not for the possibility of throwing 

 some light on the history of the region, indicating some- 

 thing of the nature and direction of the forces applied, 

 and illustrating in nature, even though in miniature, some 

 of the principles involved in rock movement. All of the 

 faults under observation occur in the Hamilton shale. 

 The difference in physical properties between the Enclinal 

 bed of the Hamilton and the vastly greater shaly portion 

 throw the faults therein occurring into two obvious 

 classes, though both are of the "low-angle" type. Those 

 in the Encrinal are conspicuous enough to one on the look- 

 out for them, but undoubtedly there are distributed 

 through the shale countless thousands, the existence of 

 which one will never guess. Vast thicknesses of the shale 

 have no visible bedding planes and even in situ are so 

 broken up into small flat lenses, often less than an inch in 

 either direction, that only by virtue of an offset in some of 

 the numerous joint planes is the presence of a fault 

 detected. But little is therefore known of the movements 

 within the shale, for its tendency to split up into this mul- 

 titude of lamellae at once destroys any record which might 



