156 
GEOLOGY OF NORTH CAROLINA. 
ing towards the mountains to 10 and 20 occasionally. The coarser pebbles 
are generally collected in a stratum at the bottom of the bed and imme- 
diately upon the irregularly eroded surface formed by the upturned edges 
of the Archaean rocks, which preserve perfectly their form and bedding 
in the quartz and mica seams, and in the differently colored earths into 
which they have passed by weathering, showing that denudation had 
overtaken the forces of disintegration, and that the whole region was 
planed down to the living rock, and all soils and earths swept away r . 
The gold gravels are no doubt to be referred to this period. The most 
notable and extensive of these are found on the flanks of the spurs and 
low ridges of the Uwharrie Mountains in Montgomery county and along 
the foot hills and inclined upper valleys and benches of the South Moun- 
tains. Some of these beds on the head waters of Silver Creek and Muddy 
Creek, and First Broad and Second Broad Rivers, — Brindletown, Brack- 
ettown, Ac., are 20 and sometimes even 30 feet thick. They consist in 
their upper portions where they lie against the steeper slopes of the 
mountains, of masses of ferruginous earth or soil, showing slight evi- 
dence of incipient stratification, the lower part of the mass for 1 or 2 to 
4 or 5 feet being filled with angular and slightly worn fragments of hard 
rocks, mostly quartz. At a few points where these accumulations have 
descended upon a slight depression or ancient ravine, the old dark soil 
remains beneath, with its roots and stumps and trunks and leaves of trees, 
grass and fruits, &c., and not unfrequently the lower 3 to 6 feet is 
bleached to a light colored earth, by the chemical action of the organic 
matter, while the upper part of the bed is brick-red. 
Such are some of the richest gold gravels of the State, on Silver Creek, 
for example, in Burke county, which have often yielded ten dollars a day 
to the hand. No better example of these pnenomena can be found than 
on the flanks and around the base of the Pilot Mountain, in the mines of 
Col. J. C. Mills. The gold-bearing gravel beds of Montgomery are of 
the same description, the famous Christian Mine among others. 
Evidently these materials have descended the slopes of the mountains 
and ridges, at whose bases, or on whose lower and gentle inclines they 
are found. By what force? Certainly not of water. Neither are they 
moraines — accumulations at the foot of descending ice masses. They are 
simply beds of till , which have crept down the declivities of the hills and 
.mountains, exactly as a glacier descends an Alpine valley, by successive 
freezing and thawing of the whole water-saturated mass, both the expan- 
sion of freezing and gravitation contributing to the downward movement; 
and with each thawing and advance, the embedded stones and gold par- 
ticles dropping a little nearer the bottom. If these till beds are followed 
