44 NEW YORK STATE MUSEUM 



the two. Southwest of Bunker hill the course is purely conjectural 

 but it may connect with the Cranberry Creek fault as shown on 

 the map. 



BATCHELLERVILLE FAULT 



The Batchellerville fault is here described for the first time, and 

 considering the boldness of topographic form due to the faulting 

 it is not -a little surprising that earlier observers have not called 

 attention to it. From the standpoint of amount of displacement, 

 and possibly also of length, this fault takes rank as one of the 

 greatest along the southern border of the Adirondacks. The up- 

 throw side is on the east and this is of particular interest because 

 we have here by far the greatest of the few Mohawk valley faults 

 which show upthrow on the east side. 



From a point two and one-half miles southeast of Northampton 

 the fault is clearly traceable northward along the base of Bald 

 Bluff where it gradually changes strike to the north-northeast and 

 then passes on a nearly straight line along the base of the mountain 

 through Batchellerville and to the map limit. The northern ex- 

 tension of the fault has not been investigated but it certainly runs 

 some two or three miles beyond the map. The southern extremity 

 of the fault is completely drift covered so that the relations there 

 are not well shown. In spite of the fact that the actual fault plane 

 is everywhere talus or drift covered it can be pretty accurately 

 mapped. 



Except for a small area to the north, the upthrow side consists 

 of a great block of Grenville gneiss which everywhere dips at angles 

 of from 15 to 30 away from the fault. Close to the fault 

 on the downthrow side, east of Northampton, there are no actual 

 outcrops but the numerous drift fragments make it quite certain 

 that the Theresa transition beds are present as shown on the map. 

 From Bald Bluff northward all the available evidence points to the 

 presence of Little Falls dolomite on the immediate downthrow side 

 except possibly near Batchellerville where the Potsdam or passage 

 beds from the vicinity of Edinburg may reach across the river. 

 The dolomite, which outcrops at several places along the western 

 side of the river, always dips at a low angle toward the fault. On 

 the mountain side, just above the feldspar mine (two and one-half 

 miles north-northeast of Batchellerville) fault breccia indicates 

 minor fracturing which most likely accompanied the major faulting. 



The amount of dislocation may be fairly well determined by 

 comparing the altitude of the Precambric on each side of the fault. 





