QUARRY MATERIALS OF NEW YORK toy 



quartz, biotite and a little hornblende are the other ingredients. 

 There are no sulphides, so far as observed. The material is well 

 adapted for all general construction purposes, as it is strong and 

 no doubt as durable as any massive granite of similar composition. 



GRANITE AT WHITE LAKE, ONEIDA COUNTY 



A pink granite has been quarried to some extent near White Lake 

 station on the Mohawk and Malone branch of the New York 

 Central Railroad. It is a medium-grained, compact, slightly 

 gneissoid rock with very little dark components which consist of 

 scattered grains of garnet and minute flakes of biotite. It repre- 

 sents a rather massive phase of the granite gneisses that are of 

 widespread occurrence in the western Adirondacks. 



GRANITIC ROCKS IN THE HIGHLANDS SECTION 



THE STORM KING GNEISSOID GRANITE 



The prominence at the northern portal of the Hudson gorge, 

 known as Breakneck ridge, is made up of a homogeneous gneissoid 

 rock that is generally called the Storm King granite. There is 

 little doubt of its granitic derivation, and the foliated appearance 

 which it generally exhibits is a secondary character superinduced 

 since its first consolidation. The granite is exposed over many 

 square miles, forming one of the larger areas of that rock in the 

 Highlands. From the characteristic members of the gneiss series in 

 the vicinity it is distinguished by its greater uniformity of com- 

 position and appearance and its usually more massive structures, 

 while it is also lacking in any marked banding or similarity to a 

 bedded arrangement. 



The granite area is limited on the north by a great unconformity 

 that separates the Highlands Precambric crystalline formations 

 from the less metamorphosed Cambro-Siluric strata of the Middle 

 Hudson region. This break marks also an extensive fault. On the 

 other sides the area is not sharply defined by topographic or struc- 

 tural features, and the granite gives way to gneisses which are for 

 the most part laminated and more or less conspicuously banded and 

 which include siliceous and calcareous members. The gneisses are 

 of early Precambric age, the banded sedimentary types being classed 

 by Berkey as Grenville. The relations of the granite to these 

 gneisses have not been definitely determined, but it appears likely 

 from what has been learned that its intrusion took place early in 

 Precambric time among the first igneous invasions that are clearly 

 demonstrated in the region. 



