LEWIS COUNTY. 267 



Specular iron ore is found in several places, associated with highly crystaUine limestone. 

 It exists near to Lewisburg furnace ; on the land of Mr. Lafarge, near Harrisville ; and in 

 localities adjoining, which belong to the second district. When first discovered, there appeared 

 to be a promise of abundance, but soon the spot was exhausted. It seems to have separated 

 from the limestone by crystalline action, like gypsum and other minerals, being frequently 

 enveloped by the limestone. Where found, it is but a superficial mass ; and though its 

 matrix is mixed in with primary rock, the origin of the two was subsequent to that rock, 

 appearing to have been local deposits of calcareous marl and oxide of iron, similar to those 

 met with in the gypseous region ; the marl and oxide separating from each other by crystalliza- 

 tion, being placed in a position which facts elsewhere prove was highly favorable to this opera- 

 tion. 



That a deposit of iron was made upon the Primary rocks subsequent to their elevation and 

 alteration of surface, is evident from the third deposit of iron ore, which, near Lewisburg 

 furnace and in St. Lawrence county, is under the Potsdam sandstone, in places intermixing 

 with the base or lower part of that rock ; showing also at Lewisburg the same limestone and 

 specular ore, the supposed associates of the Primary rocks, intermixed with the red ore ; and 

 thus proving a coimection with the Potsdam, as intimate, if not more so, than could be disco- 

 vered for the Primary mass. 



Near the Natural bridge, on the land of Mr. Cleaveland, there is a considerable deposit of 

 plumbago in small particles, much mixed with the rock. Where the particles of the rock 

 are large enough to be seen, they show that it is composed of chlorite, idocrase, quartz and 

 probably feldspar, the latter not recognized ; and more rarely minute scales of red oxide of 

 iron, which in one specimen formed a vein as to form, of a quarter of an inch in thickness. 

 The deposit has given rise to some Uttle excitement, from a belief that it was a silver ore. 

 Associated with the plumbago rock, there are others which were noticed in St. Lawrence, 

 probably of similar composition ; some containing pyrites in cubes, and a peculiar white 

 fibrous and cellular mass with plumbago, never before seen excepting between the ore beds 

 of Parrish and Kearney near Somerville. In the rear of the deposit, are the usual gneiss 

 and granite rocks ; but the whole of the former products appear to be referable to the Ta- 

 conic or Intermediate period of the Primary and the Potsdam sandstone. 



The Potsdam sandstone forms two low short ridges on the Lewisburg furnace tract, and 

 one near Harrisville. It appeeirs in all three ridges with the same characters as at Potsdam, 

 and equally valuable for ordinary building and for the lining of furnaces. Besides its utility 

 for such purposes, it is an important rock in that section ; for under it, and upon the Primary 

 rock, the specular and red oxide of iron were deposited, such being the position of these ores ; 

 and whatever ore the rock covered, must there exist. It is certain that ore exists under the 

 two ridges near the furnace, but the quantity is yet to be determined. 



The fucoidal layers of the Calciferous group were seen on the road from the furnace to 

 the Natural bridge, and from the bridge to Carthage, the latter locahty being in Jefferson 

 county. The rock appears there with the same characters as on the Mohawk, and the Calci- 

 ferous sandrock proper was not seen in any part of that section. 



