SPECULAR OXIDE OF IRON. 



93 



for, ill many points, the masses have been penetrated through, and to the rock beneath, and 

 upon which it appears to rest. 



In order to exhibit this form, I shall give several diagrams, which will serve to illustrate its 

 mode of occurrence, as well as the geological relations of the rock itself. 



The first in order, is a section of the Parish ore bed in St. Lawrence county : 



S4. 



0, a, High blulTof specular osido ; h, Adil wtiich has l)een cut through the hill 

 line ; d, Gneiss ; e, e, Potsdam sandstone. 



, Serpen- 



This mass covers a wide area ; its extent has not been determined by the excavations, but 

 its depth, particularly at the south end, is found to extend to but eight or ten feet, as the ore is 

 cut entirely through, so as to disclose the serpentine beneath. It appears, from an inspection 

 of the locality, that a large amount of ore must at some former period have been swept away, 

 as there are extensive removals of rock and materials which must once have covered this par- 

 ticular mass. 



The next diagi-am of this series, (fig. 25,) shows a continuation or extension of the Parish 

 bed to the northwest about forty rods, where an extensive excavation has been made, which is 

 called the Kearney bed. A few rods to the south of the Parish, and also to the north of the 

 Kearney bed, we find the Potsdam sandstone ; at the former place, dipping to the south, and 

 at the latter, to the north ; or, in other words, thrown off in opposite directions from the 

 masses of ore. An arrangement of this kind clearly indicates the nature and cause of changes 

 at this place, which appear to have resulted from an uplift, or an outburst of the ore in con- 

 nection with the serpentine beneath it. That the serpentine and the specular oxide were the 



c, a, Sandstone ; 6, Excavation of the Keaniey bed ; c, Adit in the Parish bed ; d, d, Ore ; e, Serpentine. 



rocks which created this disturbance in the position of the sandstone, seems highly probable 

 from the fact that no igneous rocks, as trap or greenstone, appear in the vicinity. This fact, 



