FRACTURES AND DISLOCATIONS. 133 



Before I pass to the consideration of another subject, it seems proper to state that this 

 fault probably forms the most western limit of that disturbed district so often referred to in 

 these reports, and which occupies the whole of the territory between the Hudson river and 

 the Green mountains. The rocks, it is true, are inclined as they approach the primary : 

 still their dip is much less than towards the Hudson river. Not far from Schenectady, the 

 slates and shales of (he Hudson river are horizontal ; but three or four miles east upon the 

 canal, they are greatly disturbed. Draw a line then north or a little east of north from 

 Schenectady to Saratoga-springs, and then onwards to Baker's falls on the Hudson, and it 

 will pass near the line of fracture, where, upon the west side, the rocks are but slightly 

 inclined, and on the other they dip precipitously to the east, and in this state underlie an 

 immense extent of territory. This fault appears to be cpjite similar to that at the falls 

 of Montmorenci in Lower Canada. 



The disturbed district does not end or terminate, as has been described by Mr. Rogers, 

 by a gradual opening of the curves of dip ; but the dips continue with very little variation 

 to the very line or place where they terminate abruptly in horizontal strata, and with a 

 simple fault or fracture. This is the fact throughout the whole extent of New-York. It 

 may be observed at numerous places along the Hudson valley, as at Coeymans, Coxsackie, 

 and Kingston. Still there are numerous inverted curves, and undoubtedly many points 

 where the phenomena indicate lateral pressure. Indeed it seems impossible that the strata 

 under consideration could have been fractured and broken without this lateral pressure, 

 which would produce very frequently curves and arches of various kinds. 



§ 14. Fractures and dislocations of the rocks belonging to the champlain division. 



It is frequently impossible to determine the era of any given fracture, for the reason that 

 the series of rocks may be incomplete and deficient. It is notwithstanding well determined 

 that the consolidated sediments have been fractured or broken, and also that this has taken 

 place at certain periods, though it is not pretended that these intervals were regular ; that 

 is, that disturbances have prevailed and continued during certain periods, when they have 

 ceased, and the territory has remained in a quiescent state for an indefinite time. In one 

 word, it is supposed and maintained that changes of the kind which are under considera- 

 tion, have been paroxysmal. A feature which is very common in faults and fractures of 

 strata, is the nearly linear direction they pursue : in this feature they are analogous to 

 dykes, which may often be traced forty or fifty miles in a continuous route. 



Two other facts render the subject of faults interesting and important. It is not un- 

 common that they have been made the repositories of valuable ores, when they become 

 in fact metallic veins ; and, again, from them issue some of the most important mineral 

 springs. For these reasons, I propose to notice some of the faults and fractures which 

 traverse the strata composing the Champlain group. 



Commencing, then, with the lowest member, the Potsdam sandstone, we find this rock 



