MAGNETITE IRON DEPOSITS OF SOUTHEASTERN NEW YORK 109 
obtain sorted ore rich enough to smelt. The high sulphur content 
made roasting necessary, but modern methods of concentration would 
remove much of the sulphur existing as pyrite provided the pyrite 
was not too intimately mixed with the magnetite; pyrrhotite is more 
difficult to handle by magnetic methods. 
There are no additional data obtainable with respect to this 
property. 
The O’Neill (or Nail) and the Forshee mines. These two old 
workings lie about 3 miles south of Monroe; the Forshee mine is 
one-half of a mile southwest of the O'Neill. Both mines have been 
inoperative since 188o. 
They were operated by the open-cut method; the openings on the 
O'Neill ore-band along the strike of the ore cover a distance of nearly 
1500 feet, and in places are fully too feet or more in depth, and 
from 100 to 200 feet wide. They are now brush-grown and more or 
less filled with fallen blocks. Judging from the size of the rock 
dump, and the extent of the workings, it was necessary to mine 
much mixed rock and ore in order to obtain picked material of 
furnace grade. The deposit was probably lean and streaky. Accord- 
ing to Putnam’*”’, who seems to have regarded the O’Neill and 
Forshee as one mine, the ore alternates with rock in “ layers,” and 
carries 40.33 per cent iron, 0.02 per cent phosphorus and 0.453 per 
cent sulphur. 
The Forshee mine, separated from the O’Neill by an area of low 
ground, was worked through an open cut some 4oo feet long. Here 
may be seen beautiful examples of swamped blocks of Grenville in 
all stages of assimilation; in places may be found partly assimilated 
fragments surrounded by reaction rims of hornblende, some of it 
very coarse, which in turn is surrounded with coarse hornblendic 
pegmatite, the dioritic facies of the Pochuck. 
On the dumps of both mines, but more especially the O’Neill, 
specimens may be secured carrying characteristic contact minerals, 
such as chondrodite, garnet, spinel, coccolite, tremolite, glaucophane, 
epidote, serpentine, actinolite, and the like (see plate 14, figure 1) ; 
almost pure glaucophane rock forms part of the northwest wall of 
the cut at the O’Neill mine, which shows replacement in part by 
magnetite (see plate 14, figure 2). In addition, coarse Pochuck 
granite, and in places coarse Pochuck pegmatite occur in the walls, 
and occasionally partially assimilated Grenville in the form of more 
or less completely absorbed blocks having finer texture and carry- 
162 Putnam B, T, Tenth Census Report, 1880, 
