The Xorth Carolina (Fentress) mine is 9 to 10 miles south of Greensboro. The general strike of the vein is N. 25° E.; its dip ranges from 38° to 60°. The quartz outcrop has been traced for three miles. The ore is chalcopyrite in quartz and siderite, containing gold. It was formerly worked for copper. The mine has been opened to a depth of 310 feet, where the ore-shoot was 80 to 90 feet long and 31 inches wide. The thickness of the vein varies from this to as high as 13 feet. It was last worked in 1856, and the ores which were shipped ranged from 14 to 23 per cent, copper.
The Twin mine is six miles southwest of Greensboro. There are two parallel veins separated by 4 feet of slate. The strike is 1ST. 40° E. and the dip S.E. The thickness of the vein is about 18 inches, the ore being auriferous quartz, carrying chalcopyrite.
The Gardner Hill mine is three miles northeast of Jamestown. There are supposed to be three veins on the property. The main vein strikes X. 20° E. and dips westward. Its thickness is from a few inches to 3 feet. The vein-matter is auriferous quartz, carrying chalcopyrite and some pyrite. The wall-rock is granite, with a slaty gouge on each side of the veins. The mine has been opened to a depth of 110 feet. It is stated * that the ore ran from $10 to $20 per ton and that the mine yielded $100,000. It is estimated that the present dumps contain 25,000 tons of ore. Tentative assays show $3 to $10 per ton.
The North State (McCullough) mine is situated about two miles west of south from Jamestown. The vein strikes northeast and dips 45° to 80° S.E. The mine was opened to a depth of 325 feet, where the vein wTas 4 to 8 feet thick. At the surface it was 2 feet; at the 60-foot level, 4 feet; at the 90-foot level, 10 feet; and at the 130-foot level, 24 feet in thickness. The ore is quartz carrying gold and sulphurets (pyrite and chalcopyrite). The brown ores extend to a depth of 130 feet and are said to have yielded from $1.50 to $5 per bushel ($15 to $50 per ton).
The last work was done at the depth of 325 feet, where the vein varied from 4 to 8 feet in width. The equipment consisted of 20 stamps and other machinery, which were last operated in 1884.
The Jacks Hill is on the northern, and the Lindsay on the southern extension of the North State vein.
MINES IN RANDOLPH COUNTY.
The mines are in the central and western part of the county. The country-rock is argillaceous and chloritic schist, probably in large part sheared eruptives. At the Hoover Hill the rock is a massive porphyrite.
1 Emmons, Geo!. Rept. Midland counties of N. ., 1856, pp. 174, etc.
