136 
[Assembly 
II. SPECULAR OXIDE OF IRON. 
General Remarks. 
The specular iron ore, with the variety micaceous oxide of iron, 
is extensively distributed throughout a great part of St. Lawrence 
county; forming extensive beds of frequent occurrence, in most 
cases rising to or above the general surface of the surrounding 
country. I have not observed this ore except in St. Lawrence 
county, though it will, probably, hereafter be found in the north 
part of Herkimer and Hamilton counties, and perhaps in the south 
part of Franklin county. From many circumstances, I am inclin- 
ed to believe that this ore will prove far more abundant in St. 
Lawrence county than is generally supposed; but more extended 
operations are required to develop the valuable character of many 
beds, which will otherwise remain unknown. 
Geological situation and associated Rocks. 
This ore occurs in beds which are more nearly horizontal than 
those of the magnetic ore, though still conforming to the stratifi- 
cation of the rocks with which they are associated. From their 
position being nearly horizontal, and having frequently a conside- 
rable extent of length and breadth upon the surface, we have less 
difficulty in conceiving them to be beds than we have of the mag- 
netic ores. 
The rock with which this ore is associated is the primitive lime- 
stone, though the gangue or matrix is frequently quartz of a por- 
ous or corroded texture, which is embedded in limestone. Al- 
though the proper geological situation of this ore is in the lime- 
stone, yet granite and gneiss are frequently interstratified with it: 
limestone, howevei', is the prevailing rock in the vicinity of these 
ore beds. 
Extent and thickness of Beds. 
Beds of this ore frequently extend to 20 or 30 rods in length and 
breadth upon the surface, and in some instances much more than 
this. The depth of none of the beds has been ascertained, though 
some have been penetrated to the depth of 30 or even to 50 feet, 
the ore continuing undiminished. 
