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GOLD IUIXIXG IX KOKI'H CAKOLINA.
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sition of their mineral contents in the open spaces through which they circulated, by relief of pressure, reduction of temperature, and perhaps certain chemical reactions. The frequent siliciheation of the slates and schists has been noted, and must be ascribed to this permeation of the silicified waters.
The character of the quartz varies from saccharoidal to vitreous, usually inclining to the latter. The sulphurets are chiefly pyrites; chalcopyrite, galena, mispickel and zinc-blende occur in certain localities, notably at the Silver Hill and Silver Valley mines, in Randolph county, 1ST. C. Copper ores (chalcopyrite) in some of the Xorth Carolina mines are auriferous to such an extent as to make them valuable for gold also, as for instance at the Conrad Hill. Tellurides have been found in very small quantities, as at the Kings Mountain mine, X. C. Among the more common gangue minerals, besides quartz and sulphurets, are chlorite, barite and carbonates.1
THE AGE OF THE OKE DEPOSITS.
The formation of the ores took place subsequent to the production of schistosity. The fact that the Jura-trias conglomerates, on the east, contain gold proves that the origin of the gold must have, been pre-.Tura Triassic. The presence of gold-bearing fissure-veins in the Monroe slates shows that their age must be Algonkian or later. The existence of orebodies in the pre-Cambrian volcanic rocks furnishes another clue; and thus it becomes probable that the age of the gold ores in the Carolina belt is Algonkian.
4. THE SOUTH MOUNTAIN BELT.
This belt is situated in the western part of Xorth Carolina, and takes its name from the South mountains, one of the eastern outliers of the Blue Ridge. The principal mining region embraces an area of 250 to 300 square miles, in Burke, McDowell and Rutherford counties, extending from Morganton to near Rutherford ton, a distance of about 25 miles, with an average width of 10 to 12 miles. The gold veins of northern Burke and Caldwell counties on the north, and Cleveland and Polk counties, X. C, on the south, as well as Spartanburg, Greenville and Pickens counties, S. C, might be considered as belonging to this general belt; but no extensive operations have been carried on there.
THE COUXTRY-KOCKS.
In the South mountain region, the crystalline rocks are for the most part Archaean micaceous (biotite) and hornblendic gneisses and schists,
1 Mr. Becker, in the paper referred to above, pp. 2T4-2T8, tabulates no less than 60 gangue minerals, besides quartz, pyrite, and the ordinary products of decomposition.
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