SI GEOLOGY OF THE TfflRD DISTRICT. 



in firtuments or parts are very numerous in the upper bed, but they are not so much so in the 



lower one. 



In the fourth district, these two beds appear to be separated by the calcareous shale which 

 contains the Pentamenis oblongus, one of the very characteristic fossils of this group, though 

 it is not continuous with the group in all places. Though in such vast quantities in that dis- 

 trict, being found also in Indiana and in the Caradoc sandstone of England, holding the same 

 relative position, it is rare in the third district, having been seen in place only at Donnelly's 

 ore bed in the town of Lenox, and to the west and south of Verona, and in fragments merely, 

 believed to belong to the upper, which is there a broken up bed, the whole of the surface 

 being uncovered to near the lower ore bed. 



The ore is very near the surface at Wadsworth's pits, and is of easy extraction. None is 

 used, nor will much of this extensive deposit be used, so long as individual interests predomi- 

 nate over national or social ones ; it being more advantageous to use Scotch pigs, either with 

 a portion of the ore, or by themselves, than to obtain iron from the ore, though it exists so 

 abundantly and conveniently. 



The ore at Wadsworth's belongs to the lower bed. It is highly oolitic ; it has brown 

 shale, and contains the Broad agnostis. In the shale which covers the ore, a few arborescent 

 appearances occasionally are seen ; they are flat, smooth, and of lighter color than ihe mass. 

 The same have often been observed upon the surface of other rocks, such as the Trenton 

 limestone. It is difficult to determine whether the cause is due to organization, or to a ramose 

 transudation of moisture collecting and arranging the fine particles of which they are com- 

 posed. They are probably referable to the latter cause, though no difficulty exists in attribut- 

 ing to them an organic origin. 



One of the best localities for observing this group is on Swift creek, which flows by the side 

 of Rodgers' machine manufactory, into Sauquoit creek ; more of its members are there seen, 

 and the order of superposition is better exposed. A series of shales, and thin layers of sand- 

 stone with fucoids, occurs between the factory and the entrance of the ravine ; the Oneida 

 conglomerate not being visible, the same mass of sandstone which is quarried at Black- 

 stone and Davis' appears, and is also quarried, and presents the same peculiar characteristic 

 fucoids and other bodies in relief, etc. The shaie above the quarry contains fossils, among 

 which is the Broad agnostis. 



The shale above the sandstone which is quarried, is from thirty-five to forty feet thick, 

 making the third mass of the group in the ascending order. The top of the shale is covered 

 by a layer of hard greenish grey sandstone, fourteen inches in thickness, upon which rests 

 the lower bed of iron ore. The ore is about a foot thick, highly oolitic, and the purest of the 

 two masses : no fossils were observed in it. Above the ore there is about twenty feet of 

 greenish blue shale, with thin layers of the same colored sandstone with fucoids, upon which 

 is the second ore bed. This is not so pure as the lower one, from a mixture of limestone 

 chiefly. It is oolitic and encrinal. The mass, for a few feet below and above the ore, is a 

 mixture of limestone, shale, etc. containing numerous fossils, among which is the Clinton 

 strophomena (S. clintonii), a shell which is flat, semi-elliptical, vnth numerous rays, well 



