6*2 GEOLOGY OF THE SECOND DISTRICT. 



then at numerous places along the eastern shore of Black lake. At Mineral Point, a lead 

 vein is connected with this rock. In a district seven miles north of Rossie, are beds of the 

 same, at the Wilson settlement. This portion of the belt of limestone disappears farther 

 north, under the transition rocks of Lisbon, Madrid and Norfolk. Eight miles to the east of 

 Rossie, in the neighborliood of the (Ixbow, there are numerous beds of primitive limestone, 

 bearing in general the same characters and the same relations to other rocks as at Grass lake. 

 They appear in low indistinct ridges, bearing a direction east of north, with granite or gneiss 

 on both sides, but frequently so intermingled together that it is difficult to find distinct lines of 

 demarcation between them. Still farther east, as we travel from Oxbow to Gouverneur, 

 insulated beds often appear. At the latter place, one of the largest of the beds of this rock 

 makes its appearance about three-fourths of a mile south of the village. It may be traced, 

 with few interruptions, south to Antwerp. Following down the Oswegatchie, numerous bluffs 

 arise, and form its banks. This portion of the limestone belt is lost, or passes beneath the 

 transition rocks, in its progress onward, as it meets the southeastern edge of the Potsdam 

 sandstone, near Parishville, Hopkinton and Dickinson. 



Another partial bell runs nearly parallel with the preceding, touching the eastern bounds of 

 Antwerp, and extending to Fowler, Edviards, and then into the unsettled parts of the county. 



If the section of country I have just described, embraces one belt of limestone only, it may 

 be estimated as bearing an average width of about thirty miles, or from Black lake to Pitcairn 

 or the eastern part of Russell. I am to state, however, that beds of limestone appear at 

 intervals from Black lake to Champlain lake. They are not as common upon the high table 

 land of Racket and Long lakes. 



I now pass to the eastern slope of the mountainous region which stretches diagonally across 

 this portion of the State, dividing St. Lawrence from Essex county. 



The most important belt of limestone on the eastern slope, commences at Johnsburgh and 

 Alhol, and pursues a northeast course along Brant and Paradox lakes, through to Port Henry 

 on Lake Champlain. In some portions of this belt, the rock is highly crystalline, forming 

 the variety usually called calcareous spar ; in others, it is merely granular. It is connected 

 with serpentine wherever the mass is large, and with which it is intimately blended, forming 

 by its mixture a beautiful compound rock. Extensive portions of this limestone are thus 

 intermingled at Johnsburgh and Port Henry. 



There arc only slight differences between this belt of limestone, and that already described 

 as passing through Jefferson and St. Lawrence counties. There are fewer beds of granite 

 with which it is intermingled ; and as a whole, it contains fewer of those interesting minerals 

 which are so abundant at Rossie and Gouverneur. Near Port Henry, there are rmasses of 

 rose quartz, veins of asbeslus, green coccolitc, blood-red mica, spinelle, etc. 



There arc still several insulated bods which require a passing notice. On Lake Newcomb, 

 in the western part of the county of Essex, limestone appears, surrounded as usual by gneiss 

 and granite. Most of this mass is impure, being a mixture of coccolite and quartz. Lime- 

 stone of a very good quality exists at Pendleton ; it is very similar to the beds at Port Henry. 



In Hamilton county, at Lake Pleasant, there are several beds associated with serpentine ; 



