304 
GEOLOGY OF NORTH CAROLINA. 
dersonville and Hickory Nut Gap; in Hickory Nut Mountain, McDowell 
county, in the spurs of the Blue Ridge, among the head waters of the 
Catawba, and again on the turnpike road, just below Blowing Rock, in 
Caldwell county, furnish numerous quarries of a very good building stone. 
There are also very notable, bare ledges of light gray granite of great ex- 
tent, near Mt. Airy, in Surry county. But it would be tedious and need- 
less to particularize, as granite and gneiss are everywhere. 
Sandstone . — The Red or Brown Sandstone of the Triassie has been 
already described, and its extent and general characteristics indicated. It 
is found in two tracts, — narrow zones, one lying along the valley of Dan 
River, near and almost parallel to the northern boundary of the State, as 
may be seen by reference to the map. The other lies in a northeast and 
southwest direction, nearly across the eastern side of the middle division 
of the State. A considerable part of this formation consists of sand- 
stone — red, gray and variously colored, and of various grain and texture. 
These afford many quarries of fine building stone. One of the best yet 
opened is near W adesboro, in Anson county. It is reddish-brown to buff 
colored, and of fine and very uniform grain. I have seen nothing from 
Portland, Conn., of on Fifth Avenue, superior to it. Quarries have been 
long opened in most of the other counties along the line of its outcrops; 
in Chatham, for example, near Egypt, above and below, on the river and 
on the railroad. Other quarries of note are found on the North Carolina 
Railroad, near Durham, in Orange. Stone from this locality has been 
long used for building in Raleigh. Two specimens examined lately with 
reference to constitution and probable durability, showed that the cement- 
ins material of the quartz sand consisted mainly of iron oxide and clay, 
each about four and a half per cent, in one, which is of a dark-reddish 
brown color, and two per cent, in the other, which is light gray. The 
former also contained one and three-quarter per cent, of lime, an equal 
quantity of magnesia, and eight-tenths per cent, of soluble silica; the lat- 
ter respectively three-quarters and nine-tenths percent, of the same sub- 
stances. These, however, did not appear to have much cementing effect. 
The samples were taken from large blocks, fresh from the quarries, and may 
be regarded as giving a fair representation of these sand-stones, in their 
general character. 
Marble. As elsewhere stated, there are several ranges of beds of 
crystalline limestone in the middle and western regions. The first be- 
longing to the Ring’s Mountain belt, contains so far as yet known, very 
little marble, that may be considered as available for the purposes of orna- 
mental architecture, or regarded as better than other common building 
stones. In the extreme west, however, in Macon and Cherokee, the 
