96 GEOLOGY OF THE SECOND DISTRICT. 



the impression that it might have been an aqueous deposite upon the gneiss, and previous to 

 the formation of the sandstone ; and that the serpentine, which is so constant an attendant on 

 the ore, was merely a pecuhar mud. But taking all the phenomena together, it is evident 

 that such an explanation by no means meets the case ; and furthermore, that it is more 

 rational to suppose the ore and serpentine to have been forced out from beneath through pre- 

 existing fissures. 



Serpentine Breccia. 



I have already adverted to the singidar breccia formed of serpentine and quartz, among the 

 beds of specular oxide. At first, the green mass which I have so constantly found in them, 

 was not recognized as serpentine ; and it was not until after a careful examination, that I was 

 satisfied of its being this rock. Usually the quartz is so perfectly incorporated with it, that it 

 appears to-be cotemporaneous in its origin ; but I fell in with masses of it at the Sterling bed 

 in Jefferson county, where it is perfectly easy to separate the angular mass from the rock, 

 and in this state they present no appearances of a union or incorporation with the mass at all, 

 no more at least than what would take place by the inclosure of the fragments in a paste 

 which forms the breccia of any rock, whether volcanic or aqueous. 



Topographical Position of the Specular Oxide. 



The topographical position of the specular oxide is, for the most part, in valleys, a position 

 due to the physical changes of the surface of the country. There has been first, a slight up- 

 heaval of the beds of sandstone, beneath which lie those of the oxide of iron. In the second 

 place, currents of water have swept over the surface, bearing away the loose fragments which 

 had been formed by fracture, and also apparently extending wider and deeper the breach of 

 continuity by abrasions. 



It appears from an inspection of the surface in the immediate vicinity of these beds, that a 

 large amount of ore has been swept away and carried to the south, to form new deposites, 

 which will be found to consist of the peroxide of iron, in combination with lime, silcx and 

 alumina. Such a combination we find in the oolitic and argillaceous iron in the county of 

 Wayne, and also far westward. I have even seen masses of the ore in boulders, far south of 

 any of the known beds of the specular o.\ide. It is not my purpose, neither is it my province, 

 to speak of the argillaceous ores south of Lake Ontario. Neither do I suppose that the same 

 current which transported the boulders of the specular oxide, and which we find intermixed 

 with diluvial, transported also the materials which compose those ancient beds of the oolitic 



Note. It i.s clear that the specular ore in Jefferson and St. Lawrence counties is much older than the oolitic of Wayne, and 

 that the latter must have been derived from a distance, and deposited in the same manner as the sedimentary rocks in connection 

 ■with it. But the diluvial action which transported the boulders of this ore south, and which we now find upon the surface, was 

 much more recent than that which carried the ferruginous matter into those seas in which the oolitic ore was deposited. Still it 

 is not improbable that the beds of specular oxide at the north may have furnished the materials for the beds of ore at the south. 



