RANGE OF I'RIAIITIVE LIMESTONE. 61 



3. Another very handsome variety occurs in Warrensbui-gh, on the school lot, and a part of 

 which is owned by Mr. Pressor, who furnished the fine polished slab in the State I\Iuseuin. 

 The ground is a grey limestone, with large spots of green serpentine ; which, being diffused 

 through the mass, gives it rather a mottled or clouded appearance. This is not always the 

 character of the serpentine : in many places the particles of serpentine may be separated from 

 the mass, like grains of coccohte. 



Range and Extent of Primitive Limestone. 



It is my object, in the next place, to indicate generally the range and extent of this rock ; 

 though I am obliged to remark, that I labor under the same difficulties in defining the boun- 

 daries of this mass, as in the case of granite : the same difficulties are to be encountered, 

 since the same obsciurities exist. This rock occurs so frequently in limited patches or beds, 

 or is concealed by other rocks and soil, that it is impossible to trace out the relations which 

 may exist. In carrying out my plan, I shall proceed, however, on the supposition that the 

 primitive limestone pursues a somewhat direct course or range, and that the beds which lie in 

 given directions from each other are connected beds, though there may be breaks and inter- 

 ruptions by the inten'ention of other rocks, or concealment from overlying masses of soil and 

 diluvial products. Even though this view may not prove literally correct, still it will assist in 

 description, and give an order to my remarks ; and then the localities may, if chosen, be con- 

 sidered as insulated beds, and no error need be committed by following the plan proposed. 



I shall commence the description of the range and extent of this rock at Rossie, St. Law- 

 rence county. The first beds worthy of notice, lie in the vicinity of Grass lake. They 

 occur in low parallel ridges in gneiss or granite, and pursue a northerly course. 



We raa-Y probably regard these beds as forming a part of a belt of limestone wliich comes 

 up from Jefferson county, and which lies along the eastern margin of the Potsdam sandstone, 

 or that part of the rock which runs along between Hammond and Rossie. This sandstone, 

 on the east of the main settlement of Hammond, is not broken up, so as to disclose the beds 

 of limestone beneath it ; but to the east of Rossie, on Grass lake, the sandstone is broken 

 up, and appears in parallel ridges with low grounds intervening, in which it is not uncommon 

 to find ranges of limestone accompanied with granite or gneiss. 



If the mass of limestone at Grass lake is a continuation of the rock from Jefferson county, 

 we may assume Theresa falls as its western limit, and consider it as pursuing a northerly 

 course. In following dowai Indian river, it appears as a very pure coarse limestone in a suc- 

 cession of bluffs, sometimes on one, and then upon the other side of the river. It is ever\' 

 where accompanied by primitive rocks, which bear at one place the characters of gneiss, and 

 at another those of granite. At Muscolunge lake, we find that remarkable mixture of granite 

 and hmestone, forming together a mass very subject to disintegration. Following the range 

 of countrj' adjacent to Indian river, numerous beds crop out by the side of the primitive rocks, 

 passing on to the north on both sides of the river, as well as at Grass lake. Tracing this 

 range stiU farther north, it appears first about half a mile north of the village of Rossie, and 



