372 F. H.. Bradley—sSilurian age of the Southern Appalachians. 
borhood, there are also local foldings of the overlying strata, 
but not such as to interfere greatly with the general regularity 
of the bedding. 
ough the materials of the several outcrops are quite vari- 
able, yet the variation is of so constant a character in all, that 
one would have little hesitation in recognizing them as parts of 
one bed, even without the stratigraphical reasons for the conclu- 
sion. Along Valley River, and southwestward, the rock is 
mainly a bluish or grayish-white, fine-grained marble, the pink 
tinge of the Nantahala outcrops being rarely seen and then in 
very pale tints. One layer, from eight to twelve feet thick, is 
nearly black, or black-and-white striped, compact, and capable 
of taking a fine polish, thus forming a very beautiful ornamental 
stone, but still showing, under the glass, an odlitic structure 
like that of many of the lower layers of the unaltered Knox 
limestone. This was particularly noticed on J. T. Young's 
land, about a mile northeast of Valleytown, and at the 
mouth of Lenoir’s shaft on lot “No. 6,” near Murphy. The 
full thickness of the marble, near Murphy, is estimated at about 
four hundred feet. 
Aside from disseminated grains of sand, which are sometimes 
very abundant, though at others entirely absent, the principal 
impurity of the marble is tremolite, which is sometimes present 
in quantity, either in separate, long, bladed crystals, or in 
finely radiated clusters, or in large, almost granular masses. It 
is said to form, at some points, considerable layers, consisting 
solely of it, which is certainly true at outcrops further south, 
near Gainesville, Hall County, Ga. As this mineral is essen- 
tially a silicate of lime and magnesia, it is natural to refer its 
origin to the abundant chert of the unaltered Knox dolomyte, 
which carries so much dolomyte in its intimate structure that 
it very readily disintegrates when exposed for some time to the 
action of percolating rain-water. At some points, as near Col- 
lett’s, the marble is coarse-grained, and filled with small crys- 
tals of pyrite. At “No. 6,” there isa thin layer of cellular 
quartz, possibly a true vein, filled with crystals of calcite, dis- 
minated grains and masses of argentiferous galenite and some 
free gold.* The gravel along the outcrop, for several miles, 
* The deep weathering away of the marble has caused the accumulation, upon 
the outcrop, of the gold originally disseminated through a large amount of rock; 
and surface-washings have therefore paid enormously. 
The vein-stuff, at ‘‘ No. 6,” as exposed by shaft and drift, about fifty feet below 
the outcrop, shows the following section :— 
White, fine-grained marble, with galenite, calcite and thin 
Flinty quartz, with little calcite, 
Yellowish-brown and greenish slaty limestone, 
Gree rown, compact, knotty, hydromica slate, with 
disseminated pyrite, including streak F chit ayees of 
eA. 
coarse-granular marble, 
Vv 
5 
4 feet. 
