246 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 25, 



ghanies, crossed nearly at right angles by the Ocooee river*. This 

 district and the corresponding rocks in the State of Virginia, about 

 100 miles to the north, are remarkable for the presence of several 

 large lodes, all indicated by a strongly marked gossan, underneath 

 which has been found a quantity of rich copper-ore of peculiar 

 quality. These lodes have attracted great attention in America, and 

 the ore lying under the gossan has been rather extensively worked in 

 four mines, and partly opened in others, but hitherto without much 

 profit, owing to the enormous cost of conveyance from the mines to 

 a market. Notices of the mines will be found in Whitney's ' Metallic 

 "Wealth of the United States,' and reports on the district have been 

 published by some American geologists ; but little attention has been 

 paid to what seems to me a most essential feature, and I propose 

 here to describe the lodes and the mineral field from notes made 

 during a careful investigation in the winter of 1854-1855. 



The country consists of altered talcose and chloritic schists, pro- 

 bably of Silurian date, alternating with hard micaceous grits and 

 with other rocks distinctly crystalline and of a porphyritic character. 

 All these have the same general strike as the mountain-range, which 

 bears N. 30° E. by S. 30° W., and all show a great uniformity in the 

 direction and amount of their dip, which may be described as uni- 

 formly S.E. at a high pitch. The talcose schists occasionally pass 

 into garnet-schists, and sometimes become steatitic. 



The schists and other rocks are traversed by, or alternate with, 

 numerous bands, veins, or strings of quartz, hard and crystalline, 

 irregular in extension and thickness, but on the whole corresponding 

 in bearing with the schists. These quartz-strings are neither regu- 

 larly stratified with the other metamorphic rocks, nor do they cross 

 the stratified rocks after the manner of true metalliferous veins. 

 They rather suggest a different origin, reminding one of the segre- 

 gated strings of calc-spar in certain lime-rocks, or of strings of sul- 

 phate of baryta and gypsum in clays. In the Ducktown district, as 

 indicated in the map (diagram, fig. 4), they occasionally diverge from 

 or converge towards each other ; they unite in one place to form a 

 large quartz-knot, and they are sometimes seen crossing the schists 

 nearly at right angles to the direction of their strike. 



The width of these veins varies from a few inches to 10 or 15 feet ; 

 and either at or near the surface the quartz often has a strong ferru- 

 ginous stain, or contains, disseminated through it, a quantity of iron- 

 oxide, forming a gossan, as already alluded to in the case of the 

 cupriferous lodes. The iron-oxide is generally a brown haematite ; 

 but magnetic iron-ore is not unfrequent, and in the spot marked on 

 the map as a quartz-knot, I observed the compass to be strongly 

 affected, although there was no surface-indication whatever of a 

 lode. Stains of iron-oxide are not uncommon in the schists, even at 

 some distance from the quartz-outcrops, so that the soil is in many 

 places either of a deep ochraceous yellow, dark reddish-brown, or ver- 

 milion tint, from the large quantity of decomposed iron-oxide close to 



* This river afterwards runs through a narrow gorge in the mountains, and 

 ultimately enters the Hiwassee, an important tributary to the Ohio. 



