REPORT OF THE DIRECTOR AND STATE GEOLOGIST 



the extreme from south to north and about 8 miles from east 

 to west. In the southern part, except along the western edge, 

 ' it is a sandy plain, through which occasional ledges of Ordovician 

 strata appears, more particularly near the Hudson. The plain is 

 prolonged to the north in two valleys, one of which, the smaller, 

 traverses Caldwell to the head of Lake George. The other, which 

 is larger and more open, extends northward on the eastern side 

 of the township and reaches Lake George some 3 miles from its 

 head. Both these depressions are primarily due to faulting, as 

 several observers, but more particularly X. H. Darton, who is 

 cited under Caldwell, have already noted. 



From the sandy plain and in marked contrast with it, Luzerne 

 mountain rises abruptly along the western side, and attains an 

 altitude of 1500 feet or more. It marks the boundary between 

 Queensbury on the east and Luzerne on the west. Farther north 

 French mountain forms an abrupt and isolated ridge along the 

 boundary with Caldwell and separates the two valleys, just re- 

 ferred to, which extend to Lake George. The peaks of French 

 mountain range from above 1400 to slightly more than 1500 at 

 the extreme crest. Both French mountain and Luzerne moun- 

 tain are gneiss, while the paleozoic strata lie in the valleys. 



The northeastern boundary of Queensbury runs along the base 

 of a high ridge of gneiss, of which Sugar Loaf, in the town of 

 Fort Ann, is the southern extremity, but which is almost en- 

 tirely in the latter town. 



Geology. The large geologic map of the state gives the dis- 

 tribution of the geologic formations with such correctness that 

 it seems unnecessary to redraw it at this time. Our attention 

 being specially directed to the old crystalline rocks, we have 

 given but passing notice to the paleozoic strata. The latter have 

 however been studied by several observers within the last few 

 years, and as noted below. 



Mr Hill crossed Luzerne mountain on the highway due west 

 of Glens Falls, and collected specimens 54 and 55, of the gneiss — 

 that is the country rock. Specimen 55 is a green, granulated rock 

 with a well developed foliation. When examined microscopi- 

 cally, it is found to be an aggregate of microperthite, orthoclase, 



