CALCIFEROUS GROUP. 31 



Other masses. They make a good building stone, and are quarried for the enlarged Erie 

 canal at Sage & Reed's quarry, south of the Mohawk ; at Canajoharie, at Tripes hill, &c. 



Fossils are rare in the calciferous sandrock ; but in the fucoidal layers there are many 

 individuals, though the kinds are few. Most of them are peculiar to this rock, and will subse- 

 quently be noticed. 



The Calciferous group is confined entirely to the counties of Montgomery, Herkimer, 

 Oneida and Lewis. It occupies a large portion of the space in Montgomery county, which 

 lies between the Mohawk river and the Primary region, but is concealed to a considerable 

 extent by alluvion, which is abundant in all that part of the county where this group forms the 

 surface rock. The calciferous sandrock is found but in few places on the south side of the 

 river, in none of which does it extend for more than a mile from the river. In Herkimer, it 

 is confined to the margin of East Canada creek, to the valley of Spruce creek, to the uplift 

 at Little-Falls extending on both sides of the river, and lastly to West Canada creek, com- 

 mencing about three and a half miles below Middleville, and extending to the line of Oneida 

 county, into which it projects a mile or two, being the only place where the group was observed 

 in that county. In Lewis, which is the last of the counties where the group exists, it is 

 equally as limited as in Oneida, appearing only on the road between Lewisburg furnace and 

 the Natural bridge, and on the road from the bridge to Carthage ; the latter locality, however, 

 may be in Jefferson county. 



It is not unlikely that the calciferous sandrock runs out in its progress through Oneida by 

 East Canada creek, as it was not seen in any part along the range of the primary through 

 Ohio, Oneida and the Black river ; nor was there any fact observed along the same range, to 

 induce the belief that a fault existed by which the primary was upraised, concealing the rocks 

 below the Black river limestone in Lewis county. It is very possible, that from a change of 

 character not attended to, the calciferous may in part form the base of that limestone. Not 

 knowing the calciferous sandrock in New-York, but as it appears on the south side of the 

 primary range in the third district, there was nothing to show that a change of character had 

 taken place, especially if connected with a rock little developed in the district. 



The fact made known by Dr. Emmons, that the calciferous rock which rests upon the 

 fucoidal layers is thicker in the second district than the same mass below the layers with 

 fucoids, which knowledge was acquired at the close of the survey; the fact also of the 

 water lime burnt at Van Eps's on the Mohawk, near the line of the third district, being above 

 those layers ; the presence of similar layers in the northeast part of Lewis county, and of the 

 Potsdam sandstone ; these" facts, together with that of the total absence of the calciferous sand- 

 stone in all that region, so far as was observed, require, in order to obtain greater accuracy, 

 that as the Black river limestone is of considerable thickness in Lewis county, the lower part 

 should be re-examined, and by one acquainted with these masses as they exist in the second 

 district, where, according to Dr. Emmons, they are of great thickness, and embrace his Chazy 

 limestone, a mass not noticed in the third district. 



As a marked difference of character exists between the calciferous sandrock and the fucoi- 



