GEOLOGY OF THE VICINITY OF LITTLE FALLS 71 



Now this region has been continuously above sea level for a 

 long time, long enough fior erosion to have pared away all rocks, 

 hard as well as soft, down close to base level, and this not onlv 

 once but more likely several times. That the district is not in 

 this leveled condition but has, well developed, the topographic 

 features outlined above, hard rock escarpments, soft rock valleys 

 and terraces, is in itself indicative of renewed uplift, and that of 

 no very remote date. 



There appears also to be evidence that, prior to this uplift, the 

 region had persisted sufficiently long at the previous elevation to 

 have become pretty thoroughly worn down. Such evidence of 

 this as exists in the immediate neighborhood is found in the con- 

 cordant altitudes of the Adirondack hilltops to the north, and the 

 hard rock plateau summits to the south of the Little Falls sheet. 

 But the district in question is not sufficiently covered by the new 

 maps, nor is the writer's personal acquaintance with it sufficiently 

 extensive to warrant more than the simple statement of his belief 

 that the Cretaceous peneplain, recognized as of wide extent over 

 much of the eastern United States, is re<;ognizable in the south- 

 western Adirondack region. 



Influence of the faults on the topography 



As newly formed, faults like that at Little Falls produce lines 

 of cliff known as fault scarps along the edge of the upthroAvn 

 block. Though faulting is a slow process, and though the rising 

 upthrow side is subject to more rapid erosion than the other side 

 because of its greater elevation, so that in all likelihood no fault 

 scarp has ever had a hight equal to the amount of the fault's throw, 

 yet newly formed faults should present scarps whose hight should 

 represent a very respectable percentage of the amount of throw 

 at least. 



As time passes, the greater wear on the upthrow side will cut 

 it down to the level of the other and the scarp will cease to exist. 

 It may be made to reappear in one of two ways : first, by renewed 

 faulting taking place along the same line; second, by renewed 

 uplift of the region without faulting. In the latter case the rock 



