86 GEOLOGICAL SURVEY 
The “deposit or branch mines” generally consist of beds of gravel, and pebbles of quartz, frequent- 
ly water-worn and rounded, but sometimes angular fragments are intermingled in the beds. They 
are confined to the beds of streams in valleys and low places, but very often the soil on hill sides 
is washed for gold. They vary in thickness from two to ten feet, although the auriferous portion 
seldom exceeds two or three feet. 
The gold is not scattered indiscriminately through these beds, but is found very generally near 
the bottom, resting upon the underlying rock, which, if at all disintegrated, the miners call slate, 
although it is frequently granite. Occasionally beds of clay, sand, or gravel are interposed between 
the gold-bearing beds. ‘The space covered by these deposits is frequently quite considerable. In 
Tomassic Valley a deposit occurs covering an area of many acres; and on one of the branches 
of Tyger a mine of this character occurs, extending a mile in Jength, and having a breadth of 100 
yards. At this locality the auriferous gravel varies from eight inches to three feet in thickness, and 
is overlaid by a bed of pebbles six to eight feet thick; the whole occupying a flat between two hills, 
and covered by a fertile soil of considerable depth. This interesting deposit rests upon mica slate, 
having a very irregular surface, and exhibiting unequivocal marks of the action of water. 
Although these deposits occur upon the banks of streams, yet it is quit evident that these 
streams, for the most part, had no agency in their formation. The quartzose pebbles, rounded and 
polished as they are, by attrition, and spread over a large area, cannot be referred to the action of 
causes at present in operation in the State. Other deposits there are, composed principally of angu- 
lar fragments of quartz, intermingled with the ruins of rocks from adjoining hills, which can gener- 
ally be traced to their original site. Such deposits as these belong to the present era. Indeed the 
operation of the formation of such may be seen in the vicinity of the mines that are situated on 
hill sides. The small veins that appear at the surface are broken down and washed, together with 
portions of the slates, by the rains, into the ravines and low places at the base of the hills. 
The deposit mines, then, as regards age, may be referred to two distinct periods: those consist- 
ing of beds of rounded and water-worn quartz pebbles, of various sizes, but seldom exceeding six 
inches in diameter, and generally corresponding in size with fragments into which the quartzose 
veins of the slates break by their natural fissures. ‘These constitute the most extensive beds in 
the State. Many such are found near the summit of the Blue Ridge, and in such positions as to 
preclude the possibility of the pebbles being rounded and transported by any stream or other aque- 
ous force that could have existed since that region received its present form. 
The gold of those older deposits can rarely, if ever, be traced to its original source in the veins 
in place. Partly, no doubt, from their being transported from a great distance, and partly from the 
total destruction of the veins, by denuding forces. 
A very interesting example of this sort occurs upon the summit of the Blue Ridge, where the 
western waters are divided from those that flow into the Atlantic. The deposit is composed of 
rolled rocks and angular pieces of feldspar, with garnets torn from the adjoining rocks. 'The whole 
deposit bears evidence of having been brought from the opposite or northern side of the mountain. 
The Tomassic beds: those on the Tyger, already mentioned, belonging to Mr. Carson, are of 
this character. At the foot of Poor Mountain, and at Rankin’s, on Little River, similar deposits 
occur. At none of these localities could the existing streams have had the slightest agency in the 
deposition of these beds. 
