160 NEW YORK STATE MUSEUM 



site, as we are uncertain how far the area there partially colored 

 may extend. 



The prevailing strikes of the gneisses are northeast and north- 

 west. The dip is more often to the east than to the west, though 

 some western ones have been recorded. These relations are prob- 

 ably due in part at least to faulted blocks, whose steep escarp- 

 ments look off to the westward. The drainage lines are in most 

 cases either northeast and southwest or northwest and southeast^ 

 following great structural breaks along these directions. 



Hornblende schists or amphibolites are occasionally present in 

 the areas colored as gneiss, and in one or two cases either in the 

 township or just across its northern boundary they contain very 

 coarse crystals or crystalline masses of garnet. The garnet has 

 proved of economic value as an abrasive and is mined, crushed, 

 sized and marketed. Moore's mine, on Gore mountain, is one 

 locality, and the North River garnet co.'s mine just north of the 

 boundary of the township is another. 



Series 2. The limestones and their associated beds are found in 

 four separated areas, as drawn on the map, but, though the sign 

 for gneiss appears between them, it is quite possible that under 

 the concealing drift, they may be present instead of the gneiss. 

 The typical limestones are coarsely crystalline varieties, almost 

 always containing disseminated serpentine. They seldom reach 

 more than a few feet in thickness, and are interbedded with 

 quartzites, thinly schistose gneisses, hornblende schists and 

 granular, pyroxenic aggregates. Scapolite rocks seem likewise 

 to be present. 



In addition to the areas mapped there is a small bed of lime- 

 stone in the ledges west of the town of North River, a continua- 

 tion or associate of the much larger exposures on the east bank of 

 the Hudson in Chester. 



Graphite is quite commonly present in the limestones and is 

 somewhat richly disseminated in some of the quartzites asso- 

 ciated with them. In one or two instances it has attracted some 

 attention from prospectors. 



Series 3. The anorthosites have been discovered by Mr New- 

 land in two localities. One is on the west shore of Thirteenth 



