I08 NEW YORK STATE MUSEUM 



In general the rock is a medium-grained, grayish or reddish, 

 somewhat gneissoid granite. Parts of the exposure are thoroughly 

 massive. There is a more or less marked tendency toward pegmati- 

 zation ; streaks, dikes and irregular bodies of reddish pegmatite are 

 in evidence in most outcrops, and the granite itself shows coarser 

 phases produced by disseminated crystals of the same red 'feldspar 

 that occurs in the pegmatite. Inclusions of a dark hornblendic 

 rock also occur. They may represent dikes which have been broken 

 and crumpled, or perhaps are bands of the surrounding gneisses 

 which have been caught up in the granite at the time of its intrusion. 



Jointing is usually a marked feature, but is irregular in direction 

 except in the case of shear zones which are not infrequent. In 

 these zones the rock is usually too broken to afford much dimension 

 material. The surfaces of the sheared granite show some decom- 

 position and are often coated with chloritic minerals. 



The granite from this area could hardly be quarried economicall)' 

 for architectural building stone, but is serviceable for foundation or 

 rough work, as well as for crushed stone. For crushing purposes it 

 is fully equal to the average granite, as the foliation is not suffi- 

 ciently developed to affect its strength or to cause the stone to 

 fracture readily in that direction. 



Quarries on Breakneck ridge 



Quarry sites are found along the south side of Breakneck ridge 

 for a mile or more back from the river and in the past have' yielded 

 large quantities of constructional stone, paving blocks and crushed 

 stone. Quarry work began here in the early part of the last century, 

 probably before 1825. For the last few years the output has been 

 intermittent and small. 



The principal operations have been carried on at Bailey's quarry 

 just east of the river and 100 feet above the base of the ridge. The 

 quarry face extends 300 feet east and west and, is cjuite 100 feet in 

 height. The quarries were equipped at one time with a crushing 

 plant which supplied material for highways and railroads but this 

 has been dismantled. The quarry work itself has not demanded 

 much ecjuipment as the plan usually followed is to break down the 

 stone in large blasts and to utilize the product for different purposes 

 according to its quality and size. 



Microscopic examination. The granite belongs to the hornblende 

 variety, having a dark green hornblende as the ferromagnesian 



