DISTRIBUTION AND EXTENT OF AURIFEROUS ROCKS. 
165 
oid granite, at many places; and the Potsdam sandstone, or in 
its absence the calciferous sandrock, rests unconformably upon 
the Taconic slates and other members of the same system. The 
auriferous rocks, therefore, are inferior to two systems, and the 
lines of demarkation between the systems are so distinctly 
drawn, that they should not be overlooked. There is no evi¬ 
dence that the lower Silurian are metamorphic rocks, which 
contain the gold of this country, though this veiw is taken by a 
distinguished geologist in the governmental survey of Canada. 
Several rich auriferous veins traverse a hornblendic gneiss 
in Rutherford, N. C., at the eastern base of the Blue ridge. On 
the west side of the same ridge gold is derived from mica slate, 
four miles west of Sowannanoe gap. I entertain the opinion 
that we have no facts which sustain the doctrine that the rocks 
of the Blue ridge are altered Hudson river sandstones and 
shales, and yet the Blue ridge, where it is auriferous, is identi¬ 
cal with the Green Mountain range. 
DISTRIBUTION AND EXTENT OF THE AURIFEROUS ROCKS 
EAST OF THE MISSISSIPPI VALLEY. 
§ 101. We can not with certainty determine the extent of the 
auriferous belt of the Atlantic slope. Its width in North Caro¬ 
lina is at least one hundred miles on a line, passing through the 
state from southeast to northwest; but the area over which 
gold has been found, is equal to 10,000 square miles. It is found 
in this state, in all the counties lying west of Wake, and is from 
fifteen to thirty miles wide in Virginia. One gold vein only is 
known in Maryland; but the slates which usually contain gold are 
about ten miles wide. The gold vein in Maryland is at Brook- 
ville, in Montgomery county. Gold is not found in this direc¬ 
tion until it appears in Somerset, Vt., on the east side of the 
Green mountains. All that is interesting at Somerset is the 
fact that gold occurs in the same relations as at other places in 
the South. Still farther north, in Canada East, it reappears 
again, at Sherbrooke and La Chandiere river. It is associated 
