If it be taken for fact, that the quartz of the mining district was intruded in a melted state, it must also be considerd that gold was intruded with it. To account for the friable state of the quartz, moisture must be supposd to have been present, whilst the quartz was in a heated state.
Such a state of things would produce a disintegration of the quartz rock, and set at liberty the imbedded gold, to be carrid downward by gravitation from the hills into ravines, creeks and rivers. To account next, for the difference between massive imbedded gold in quartz rock, and gold disseminated in small particles, needs only to consider the quartz acting as a flux during a state of fusion, to bring the gold together, in the same manner as borax, glass or quartz will do in the artist’s crucible—and the only probable difference between the gold of California and that of Georgia, is, during a melted state of the quartz, a higher degree of heat existed in the quartz of California than that of Georgia, thereby bringing about a more perfect work of separation between the quartz and the gold.
CHAPTER XX.
Three varieties of Gold, with their distinctions, and the reasons given why they are found in separate localities.—Philosophy of running water.
FIRST VARIETY.
The first variety of Gold may be considerd as that which is in dry ravines, or between hills, where there is no running water, except in the time of showers, or the melting of snows.—This variety is calld dry ravine or angular gold, from the fact that whatever be its form, whether in plates or heavy solid masses, or in thin scales,—the edges are all sharp and angular, as nature formd it, having never been rounded off by attrition among moving pebbles or sand, in violent streams of water. The agent of deposit seems to have been mostly that of gravitation during the decomposition of the rocks of the hills containing gold, aided probably by the moistening influences of rains upon the alluvium of the hills, and the general movement of alluvium from higher to lower levels. When once deposited in these situations, it never after receives a secondary removal, except by the hand of the miner.
Dry ravine deposits vary in their advantages for obtaining gold, according to the slope of the hills, through which the ravine passes. At the heads of ravines, where the country is but an undulating one, of moderate hills, and wide-spread valleys, the deposits are generally so disseminated, that but little advantages are gaind, by searching for gold in such situations.
Downward, towards the mouths of ravines, where the hills are in close contiguity, gold is deposited in a line along the center of ravines, varying somewhat in richness, according to the richness of the adjoining hills that deposited it, or the inclination, or basin-shapd appearance of the ravine along its course to its mouth. If ravines are of rapid descent from their sources to their outlets, they mostly contribute their gold to the streams into which they empty themselves.