Cushing — Geology of Clinton County. 



531 



insignificant breaks, to great dislocations which have a throw of 2,000 feet, 

 and possibly more, and which can l>e traced for several miles. The possibility 

 of the presence of thrust faults has been constantly borne in mind, but the 

 evidence for their existence has not been forthcoming. In the majority of 

 cases the hade of the fault is not to be made out, but it is at least high. Some 

 can be demonstrated to be normal faults. By them the palaeozoic rocks are 

 chopped up into a series of small blocks, and they are so prevalent that 

 whenever the rocks are concealed much uncertainty necessarily prevails as to 

 what is beneath. It may, however, be laid down as a general proposition 

 that, in passing eastward from the Pre-Cambrian rocks toward the lake, 

 progressively younger rocks are met with. The exceptions to this in the 

 county are but few. The greater breaks have a northeast and southwest, or 

 a north and south trend, while the smaller ones range at some angle to these, 

 and so far as observed do not pass across them. 



The Pre-Cambrian rocks have necessarily suffered als«> from the distur- 

 bances of this period, but in them the fractures are often difficult to locate, 

 nor is it possible to definitely distinguish them from possible earlier faults. 

 The topography often implies faults of great magnitude, but is wholly silent 

 as to their date. Kemp has written of the frequent faulting of the ore-beds. 

 Along contacts, too, decisive evidence of faulting is often forthcoming. The 

 dikes are often faulted, the shift at the surface varying from a few inches only 

 up to the complete disappearance of the dike on one side of the break. 

 These faulted dikes give us the only evidence of faults which can, with 

 certainty, be ascribed to the later period. 



Township Geology. 



The more prominent features of the local geology in the various town- 

 ships will now be considered. The townships, in alphabetical order, are as 

 follows : 



Altona, . . . 



• Pag 



e 562 



Dannenn >ra, 



Page 



535 



Ausable, . . . 



u 



545 



Ellenburgh, 



u 



533 



Beekniantown, . 



11 



559 



Mooers, . . . 



u 



532 



Black Brook, . 



a 



541 



Peru, .... 



u 



549 



Champlain, . 



a 



571 



Plattsburgh, 



a 



553 



Chazy, . . 



u 



566 



Saranac, . 



u 



538 



Clinton, . . . 



a 



582 



Sehuyler Kails, 



a 



552 



