GEOGRAPHICAL AXD GEOLOGICAL DESCRIPTION OF GOLD BELTS. 17 THE GOLD OKES.
The gold ores in the Carolina belt exist in two principal structural forms: (1) as quartz fissure-reins; (2) as pyritic impregnations, accompanied by irregular stringer-like and lenticular quartz intercalations in the country schists and slates. The fissure-reins in the slates and schists are generally difficult to distinguish as such. Their structure is much more evident in the granitic and other eruptires. In the schists the larger and more regular quartz lodes lie apparently interlaminated with the country, or hare the appearance of lenticular intercalations; however, even here they can usually be shown to intersect the schistosity, generally at very low angles.
The age of the ore deposits is later than that of the force which produced schistosity, from the fact that fragmental inclusions of sheared country-rock are not rare in quartz. The Assuring force was, therefore, subsequent to the shearing force. Certain maximum lines of faulting may have been developed, which made room for the larger fissureveins, on either side of which smaller dislocations formed belts of variable width. It is certainly most natural that, in a rock like slate or schist, the rupturing force should hare been exerted along the lines of least resistance, that is, along the cleavage planes, and that the predominating fissures should, therefore, hare been formed in that direction. Isolated instances of cross-fissures occur, but they are rare.
A very usual occurrence of the ores is that of irregular, finely-divided disseminations of auriferous sulpliurets and fine gold, accompanied by small stringers and lenses of quartz in the country slates and schists, which are usually silicified, at least to some extent. This form of deposit bears close resemblance to the Scandinavian " fahlbands," which are described as belts of schists impregnated with sulphides. In the Southern Appalachian field they form the small and large bodies of low-grade ores (Haile mine, Eussell mine, etc.). The shape of these ore-bodies is lenticular; their outline, however, does not necessarily conform with the strike and dip of the schists, but is determined rather by the degree of impregnation. Very often, also, the wall-rock of the quartz fissure-veins is impregnated for some distance with auriferous sulpliurets.
The gravel placers of the Carolina belt present no features differing from those of similar deposits in other gold regions.
GEXESIS OF THE ORE-BODIES.
Xo definite proof of metasomatic formation of the ores has been observed; and the most reasonable hypothesis for their formation is that of the ascension and percolation of heated carbonated and alkaline waters carrying silica, metallic elements and sulphides in solution, and the depo-
