54 ^'E\V YORK STATE MUSEUM 



a fine display of fault-breccia in the Grenville gneiss. Excellent 

 broken rock zones occur along the river three-fourths of a mile 

 south of ^leco lake and also i mile west of Rock lake. A short 

 branch fault passes through INIeco lake. 



Blue Ridge-Three Ponds Mountain fault 

 There is strong topographic evidence for the existence of a fault 

 along the western bases of Blue Ridge and Three Ponds mountains, 

 but since the evidence is not conclusive, this fault is represented on 

 the geologic map by a broken line. 



Grant- Woods Lake fault 



This fault bounds the Groff-Cathead mountain ridge on the west. 

 It strikes north-northeast along a nearly straight line apparently 

 joining the Elbow-Three Ponds Mountain fault just north of Groff 

 m.ountain. Its presence is clearly proved by the t\'pe of topography 

 and the occurrence of a distinct crushed zone in the notch one-half 

 of a mile south of Grant lake. From Grant lake to Woods lake the 

 displacement is fully 700 to 800 feet with upthrow side on the east. 



Abner Brook fault 



This fault branches oft the Grant-Woods Lake fault and is 

 clearly traceable by the topography along Abner brook ; thence along 

 the eastern base of the small mountain west of Benson Center: and 

 along the western base of the Pinnacle (Gloversville sheet). The 

 upthrow side is on the west with a displacement of some hundreds 

 of feet. One and one-half miles north-northwest of Benson Center 

 the fault scarp is over 500 feet high and very steep. 



Whitman Mountain fault 

 A short but important cross-fault lies in the river valley at the 

 base of Whitman mountain. It appears to terminate abruptly against 

 the Elbow-Three Ponds ^lountain fault on the west and the Colombe 

 Creek fault on the east. Its topographic effect is yer>^ pronounced. 

 Xear its eastern end where it strikes the river, there is a fine large 

 broken rock zone with strike north 60° west. The fault which 

 bounds the Wells outlier on the east appears to end abruptly against 

 this fault. 



Other faults 



The other faults shown on the geologic map require little or no 

 description. 



