keith] IRON ORE OF CRANBERRY DISTRICT, N. C.-TENN. 245 
granites near Cranberry small veins and stringers of magnetite are 
found at many places. These may represent deposition from the min- 
eralizing solutions, where there was no body of readily altered rock 
which could have been changed into an ore deposit. Also, northwest 
of Cranberry the gangue minerals and even magnetite are developed 
in the mass of the red granite along more or less mashed zones. 
These perhaps represent the places where alteration was most active; 
that is to to say, the actual channels through which the mineralizing 
solutions passed. 
As to the cause that put into action the mineralizing solution some 
suggestions can be made. In many areas the heated solutions and 
vapors arising from bodies of intrusive rock have produced mineral 
alterations and deposits. As stated above, the magnetite deposits are 
later than the folding movements. That is also true of the Bakers- 
ville gabbro. These intrusive masses are frequent in the area of 
Roan gneiss west and southwest of Cranberry, and the magnetite 
bodies swing around their circumference. It is thus suggested that 
the magnetites are due to alterations begun by the gabbro intrusions. 
Whether true or not in this locality, this explanation does not hold 
for the magnetite deposits in Ashe County, for there are no recent 
igneous rocks in that area. 
Of the source of the iron there is as little evidence. The adjacent 
formations, the Cranberry granite and the Roan gneiss, both carry 
iron chemically combined in the biotite and hornblende. Solution of 
either might furnish the iron. There is, however, no apparent altera- 
tion or diminution of the ferruginous minerals in the adjacent granite. 
From the Roan gneiss iron might more readily have been obtained on 
account of the extreme abundance of hornblende in that formation. 
That the mineralizing solutions passed through these formations at 
more than one epoch is clear from the existence of a band of titan- 
iferous magnetite deposits parallel to and southeast of this band. 
These are as regularly titaniferous as the ores of the Cranberry band 
are free from that mineral. Inasmuch as the two belts are in close 
proximity and each is extensive without overlapping the other, their 
depositing solutions were probably active at different times. Still 
another period of mineralization left its record in the pegmatite veins 
and lenses so common in this region. These, however, were crushed 
and distorted during the folding of the strata, and thus are so much 
older than the magnetite deposits that they can have no origin in 
common. 
RED HEMATITE. 
This ore is found in one locality in this area, on the east side of 
Bull Ruffin Mountain. It occurs in the schistose metarhyolite next 
to a fault plane, and it is rather an impregnation of the schist with 
hematite than a distinct and pure deposit of ore. Little work has 
been done in development of the ore, and its value and amount are 
questionable. 
