ST. LAWRENCE COUNTY. 
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stated, has prevented the exact determination of the geology at numerous places ; and hence 
I have been obliged to rely upon established principles in designating the geology of these 
points, instead of observations made upon the spot. I trust few material errors will require 
correction by subsequent examinations. 
In the above remarks in relation to hornblende, it is not intended to convey the impression 
that it does not occur in the southwestern towns ; it is, however, rather a mineral than a rock, 
and is of frequent occurrence, but more frequently in distinct crystals. A range of gneiss 
and hornblende, of the ordinary kind, forms the shores of the St. Lawrence river southwest 
of Alexandria bay; and the same rocks also form the greater part of Wells’ island. 
This district differs also from the gneiss and hornblende districts already described. I stated 
in the preceding pages, that the granite of Alexandria, and I may add that of Hammond 
twelve miles north, is similar to the New-England granite. The same remark may be made 
in relation to the gneiss and hornblende. They occupy but a few miles of the surface ; they 
all form low ridges, and never rise higher than moderately elevated hills; they furnish no 
interesting minerals, and none of the mines of the north are connected or associated with the 
rocks of this limited district. 
Iron Ores of the Primary District of St. Lawrence County. 
One very remarkable difference in the iron ores of St. Lawrence and Essex or Clinton, is 
found in the state of oxidation. In the latter counties, though the peroxide often occurs, it 
does not appear in that distinct state of peroxidation which it does in St. Lawrence ; for here 
it is either in fine perfect crystals belonging to the forms peculiar to this mineral species, or 
else it is in the red massive or pulverulent state. It is impossible to offer a satisfactory ratio¬ 
nale of this difference. One of the great features, however, of the section in which this oxide 
occurs, is the great development of the primary limestone, and I have been disposed to look 
upon this fact as in some way connected with the differences here adverted to. 
The localities of the specular ores are quite numerous, though but few are really important, 
and furnish sufficient amount of ore to make it an object to work them. 
One of the most important localities is the Parish mine, in Gouverneur. This mine is in 
gneiss. The ore formerly formed a hill in a small valley, fifty or sixty feet high, and in cir¬ 
cumference twenty-five or thirty rods. The upper or superior part was the potsdam sandstone, 
highly charged with the oxide of iron, and some portions of it with sulphuret of iron. It 
appeared as if the whole mass of sandstone was raised up by some force applied beneath. 
Whether this conjecture is right or not, we find on either side the sandstone thrown off in 
different directions, and on each side dipping from the great mass of ore. Now upon the 
subject of the position of the specular ore when it occurs under this form, it scarcely admits 
of a question but that the mass has been projected upwards from below. It is true that the 
oxides of iron do occur interlaminated with sedimentary rocks; but the circumstances and 
condition of the masses of ore in St. Lawrence do not favor at all the theory that they have 
