ELIZABETHTOWN AND PORT HENRY QUADRANGLES 79 



Operated in 1880, it was visited by Bayard T. Putnam as agent 

 for the Tenth Census. Putnam was a most careful observer, who 

 combined the keen sight of the geologist with the habits of record 

 of the engineer. He plotted a cross section of the Cheever ore 

 shoot, which shows it to be broken by nine little faults, all normal 

 ones, although dipping first in one direction and then in another. 

 They ranged from 28 to 78 feet apart and revealed displacements 

 varying from 1.5 to 31.1 feet.^ Some years after Putnam's visit 

 the workings encountered a much larger fault which is stated to 

 have cut off the ore. 



In the large mines at Mineville not only are faults indicated by 

 the relations of the ore, but at the western side of the Old Bed pit, 

 the crushed and decomposed rock and slickensided faces can be 

 seen over a width of about a foot. In the subsequent descriptions 

 of the ore bodies these features will be again referred to. 



The accurate and instructive exhibitions of faults which the 

 mines reveal may with justice lead to the inference or at least the 

 suspicion that faults are far more abundant than we have supposed, 

 rather than that they are fewer. At all events increasing experi- 

 ence inclines us to a greater and greater faith in their existence. 

 One is even justified in regarding each topographical depression 

 as not only the possible but the probable location of one. The only 

 other probable line of weakness in the Precambric areas is a bed 

 of limestone. 



Chapter 7 



AREAL DISTRIBUTION OF THE SEVERAL FORMATIONS 



Introduction. The delimitation of the areal geology involves 

 great difficulties. The region has been heavily glaciated and in the 

 higher altitudes drift is very abundant and serves to conceal the 

 outcrops. Along Lake Champlain in the Paleozoic areas the Cham- 

 plain clays mantle the surface and afford comparatively few ledges. 

 The more mountainous districts are forested, and have been at 

 least once and often several times cut over. The younger growth 

 is thick and difficult to traverse. One might pass a ledge at a 

 short distance without detecting it. But the most unsatisfactory 

 features of all are involved in the nature of the ancient crystalHnes 

 themselves. In the preceding descriptive pages their characteristic 

 features have been set forth in as definite a way as possible in 



1 Tenth Census. 1885. 15:112-14. The 31. i feet may be a misprint 

 for 3.1 since Putnam states specifically that 13.5 is the greatest dis- 

 placement observed. 



