276 
GEOLOGY OF NORTH CAROLINA. 
The rock of the region is a gray (and usually) thin-bedded gneiss, 
with mica schists and slates. These have a prevalent strike a little 
east of northeast, and dip east at a tolerably high angle ; though 
both dip and strike are subject to considerable variation. The walls 
of the copper vein are micaceous gneiss and mica slates, with a 
strike N. 57° E., and dipping southeast at an angle of 40° to 45°. The 
copper vein is coincident in strike with the rocks, but is vertical, cutting 
across the strata in dip, so that it is a true fissure vein, and not bedded, like 
those at Ducktown. It is traceable by an outcrop of gossan for more 
than a mile, and has been proved by trial shafts and trenches for nearly 
2,000 feet. The breadth of the lode varies from about 6 feet to 15 feet, 
(is stated to measure 20 in some cases), averaging about 10 probably. 
Seven shafts have been sunk vertically in the vein, and levels driven, at 
the depths of 90 and 150 feet, these shafts and drifts often not touching 
either wall ; so that the vein is opened for a linear distance of 650 feet. 
There is, properly speaking, no gangue stone, the whole breadth of the 
fissure being filled with ore. The gossan, which is decomposed oxydised 
ore, extends to an average depth of over 50 feet in the different shafts, 
the lower half containing however a valuable percentage of copper in the 
form of oxyd and malachite. Below this level of oxydation, the ore is 
sulphuret of copper. The quantity of ore removed in the mere process 
of opening the mine is very great, (estimated at over 3,500 tons), as there 
was no loss of work, every foot of excavation being represented by its 
equivalent of ore on the surface. Some parts of the vein contain small 
portions of magnetite, quartz and garnet. Dr. T. S. Hunt had examined 
the mine a few weeks before my visit, and I give his analyses of the ores. 
He says : “ Two samples of the gossan, taken at distances of two or three 
feet above the sulphurets, yielded respectively 14 and 22 per cent, of 
copper. It is evident that a large proportion of this gossan can be treat- 
ed advantageously for copper.” Of the unaltered portion of the vein, 
he says : “ Some parts of the vein are filled with copper pyrites, mixed 
with more or less magnetite, and yielding in different specimens 17 to 22 
per cent, of copper, while a larger portion consists chiefly of an impure 
variegated ore, giving in different assays, 35, 39 and 45 per cent, of cop- 
per.” “ An average sample of fresh and undried ore from a large pile 
gave 25 per cent., and another from a large pile, chiefly of iron-black ore 
gave 36 per cent, of copper.” The average of the ores which were un- 
dergoing reduction in August, 1874, was estimated by Mr. Clayton to 
range between 12 and 20 per cent. 
