New York State Education Department 



New York State Museum 



John M. Clarke, Director 



Bulletin 107 



GEOLOGY 12 



GEOLOGICAL PAPERS 



POSTGLACIAL FAULTS OF EASTERN NEW YORK 



BY 



J. B. WOODWORTH 



Introduction 



While investigating the changes of level which have affected 

 the Pleistocene river and lake deposits of the Hudson and Cham- 

 plain valleys, the writer noted certain small dislocations of the 

 bed rock which have taken place in the comparatively recent 

 time since the glaciation of the surface. The importance of 

 these fractures as indexes of a rock movement which appears to 

 be associated in time at least with the tilting of the continent in 

 the postglacial epoch led to the following study of the distribu- 

 tion and character of the fractures. 



A reference to the literature of the State showed that Mather 

 in the original geological survey of the first district noted the 

 occurrence of postglacial faults on the east side of the Hudson 

 valley. Having first referred to a class of faults much more 



