22 NEW YORK STATE MUSEUM 



strata into the crystallines. As described by Darton they are normal 

 faults with a downthrow to the east, amounting to 800 feet in the 

 Little Falls fault and to 1600 feet in that at Hoffman. The faults 

 cut the latest of the stratified rocks represented, the Utica shale. 



An earlier period of faulting occurred in Precambric time, though 

 the displacements can be distinguished from those of later age in 

 but few cases. The ore bodies on Arnold hill have been broken by 

 a system of cross faults, and along some of these diabase dikes have 

 been intruded. The dikes are, as already stated, of late Precambric 

 age. As they show no effects themselves of any disturbance, it 

 would appear that the displacements occurred before their intrusion. 



