IRON-ORE DEPOSITS OE THE CRANRERRY DISTRICT, NORTH 
CAROLINA-TENNESSEE." 
By Arthur Keith. 
MAGNETITE. 
Deposits of magnetic iron oxide occur along a line passing through 
Cranberry in a northwest direction. The ore has long been worked 
at Cranberry and produces iron well known for its purity. Beginning 
near Old Fields on North Toe River, the magnetite has been traced 
with small intervals, south of Smoky Gap, through Cranberry, and 
on to Shell Creek in Tennessee. This line of outcrop lies in the 
Cranberry granite, which is in places mashed and metamorphosed so 
as to resemble gneiss, and it is nearly parallel to the boundary of the 
granite and Roan gneiss, a relation which is repeated in other districts 
toward the west. 
At the Cranberry mines open cuts have been made at intervals 
over an area 000 by 300 feet and through a vertical distance of 250 
feet. From these tunnels are run in for considerable distances. The 
ore occurs as a series of lenticular bodies of magnetite in a gangue of 
hornblende, pyroxene, epidote, with a little feldspar and quartz, and 
a few unimportant minerals. The ore and gangue occur as a series 
of great lenses dipping toward the southwest at angles of 45° to 50°, 
about parallel to the planes of schistosity in the gneiss. The ore is 
found in the gangue in the shape of smaller lenses, dipping southwest 
from 40° to 60°. These vary from 50 feet down to a few inches in 
thickness, and are from two to five times as long as they are thick. 
Sometimes the lenses have sharp limits, but usually the gangue and 
ore grade into each other at the contact. Considerable ore is sprinkled 
through the gangue, and more or less gangue is scattered through the 
ore bodies. The ore is very free from the objectionable elements, 
phosphorus and sulphur, though it is not high in iron. It yields an 
average of 42 to 4G per cent of iron with ordinary concentration. 
Considerable trouble is experienced in freeing the ore from the 
gangue before smelting, on account of the tough and refractory nature 
given to the mass by the epidote. 
Because of the occurrence of the ore as a series of lenses the quan- 
(i Abstracted from descriptive text of the Cranberry Geologic Folio, now in press. 
243 
