iS NEW YORK STATE MUSEUM 



Another district in this geologic province in which postglacial 

 faults have been described lies along the northern border of Ver- 

 mont and New Hampshire in southwestern Quebec. Mr R. 

 Chalmers of the Geological Survey of Canada has recently- 

 described numerous and yet more pronounced instances of these 

 dislocations in the Cambric and Cambro-Siluric slates of that 

 field, viz, in the southern part of the seigniory of Aubert Gallion ; 

 at St Evariste de Forsyth, Beauce county; east of Jersey Mills; 

 near the mouth of Gilbert river, at MacLeod crossing, Canadian 

 Pacific Railroad; east of Scotstown; between Sherbrooke and 

 Stoke Centre, etc. Some of these localities are shown on the 

 accompanying sketch map [pi. i]. 



The prevalent downthrows are stated to be toward the north, 

 but throws on the south or southeast occur. Chalmers reports 

 instances of dislocations of from 4 to 6 feet. He states that the 

 faults in this district " seem to have occurred near some ridge or 

 mountain or mass of resisting rocks, the downthrow being 

 usually on the side towards it, or rather the sliding up of the 

 slates has taken place on the side farthest from it." ^ 



An instance in New Hampshire noted by Professor Hitchcock 

 is referred to in the following pages. 



The above citations show that there is a group of postglacial 

 faults found in the belts of Cambric and Lower Siluric slates 

 over a large area with a dominant upthrow from the southeast. 



m 



Personal observations 



The following notes serve to show the character of the locali- 

 ties cursorily described by Mather and the details of examples 

 recently discovered. The localities which appear not to have been 

 earlier described by others are as follows : South Troy, Rensse- 

 laer, Defreestville, and Pumpkin Hollow. The position of these 

 places is indicated by the locality marks on the accompanying 

 sketch map [fig. i]. 



Faults in South Troy. An instructive locality of small post- 

 glacial faults was to be seen in the summer of 1904 in the south- 

 ern part of Troy, on the east bank of the Hudson gorge, south 

 of the Poesten kill. At this point the Albany clays have been 

 largely stripped off from the basal portion of the slate wall of 



^Chalmers, R. Report on the Surface Geology and Auriferous Deposits of South-eastern 

 Quebec. Geol. Sur. Can. An. Rep't. Pt J. 1898. io:oj-i2j. 



