MAGNETITE IRON DEPOSITS OF SOUTHEASTERN NEW YORK 93 
Near the north end of the Scott the ore is cut by a dike of 
pegmatite, which appears at the surface, but which wedges out down- 
ward and totally disappears on the 400-foot level, although on the 
200-foot level the drift cut through what seemed to be a very thick 
dike. 
The ore body at this point is offset by a small fault which causes 
a horizontal displacement of 40 feet, and which was encountered in 
the lower levels of the mine at the north end. 
Both the ore and the pegmatite dike are cut off by the major fault, 
which is a branch of or an extension of the one at the south end 
of Sterling lake (see figs. 6 and g). At this point on the surface 
the rock, rising in a very steep escarpment judged to be a fault 
line scarp, is very strongly granitized Pochuck-Grenville, carrying 
so much injection-quartz as to be essentially a facies of the Pochuck 
granite. | 
Much development work has been done on these properties by the 
operating company, and the mines promise to produce a large tonnage 
of excellent ore in the near future. 
The Long mine. This body of ore, about 4000 feet northeast 
of the Scott mine, was discovered in 1761 by David Jones *; it may 
be traced for nearly a mile in a sharply curving northwesterly 
direction, along which lie the old workings. The ore is split by a 
horse of country rock, making two parallel bodies, for an unknown 
distance and depth. Between the time of the discovery, 1761, and 
the date Doctor Horton’s report was issued, 37,500 tons of ore 
were taken from this mine; the ore was said to be of especially 
excellent quality, and it was used mixed with ore from the Sterling 
mine, in the manufacture of the great chain which was extended 
across the Hudson river in order to impede the movement of the 
British warships up the river during the Revolution. 
An open cut about 500 feet long, and numerous smaller pits and 
cuts constitute the workings of this mine. 
The ore was followed by drifting down the dip, under the hanging 
wall, but it is impossible to determine what the extent of these old 
workings may be. The underground portions are drowned and the 
pits are more or less caved and brush-grown. At the northwest end 
of the line of workings a large prominent pegmatite dike cuts across © 
the strike of the belt of ore, and probably cuts the ore below. 
The reputed good quality of this ore and the tonnage raised 
134 Appendix to 3d Annual Report, Dr William Horton’s Report to W. W. 
Mather, 1839. 
