94 GEOLOGICAL SURVEY 
being a continuation of the gold-bearing rocks of that State; and towards the South it terminates 
with the granite of Kershaw, or sinks under the beds of sand of the Tertiary series. 
A few miles over the line, on the North Carolina side, an excellent opportunity is presented for 
the study of the gold-bearing rocks of this part of the State; for the hill, known as Lawson’s mine, 
has been more or less opened over a space of one mile in length, and, in some places, to a depth of 
forty feet. The slates, which are very hard at that depth, seem to be composed of a flinty talcose 
rock, somewhat disintegrated towards the surface. Owing to the hardness of the slates, the sides 
of the open ents do not fall in readily, and the auriferous beds can consequently be seen to great 
advantage. Very generally they follow the contortions and windings of the slates, but in one or 
two instances I saw them crossing the ordinary slates, without veins, or any other appearance to dis- 
tinguish the productive from the unproductive portions of the slates, excepting the presence of 
oxide of iron, and the more disintegrated state of the auriferous portion, which gives it an arena- 
ceous ‘character that may be detected by the touch. From what I have seen here and elsewhere, 
Iam convinced that in many of these “slate-mines,” the gold is often disseminated through the 
slates, and only becomes evident where they are somewhat disintegrated, or where the sulphuret of 
iron, which frequently envelopes the gold, is converted into oxide of iron. The gold, which is often 
found lining the lamine of the slates, like a covering of gold leaf, is also in much smaller particles 
in these mines than in those where the gangue is massive quartz. The productive beds at this 
mine vary in thickness between half an inch and ten inches. 
The slates of this range enter South Carolina at a point a little north of Bellair, Lancaster Dis- 
trict. 'They are composed of a series of white arenaceous slates, containing tale and mica, very 
rough to the touch, and occupying a belt of country about six or eight miles wide, extending from 
this point almost to the village. It must not be supposed, however, that all of these slates contain 
gold: on the contrary, the auriferous portions are confined to patches of limited extent, scattered 
over this area. Cureton’s and Ezell’s mines are near the line, and when I saw them they were 
quite promising. At the latter mine I found as fine hand specimens as I have seen any where. It 
requires great caution and much skill to judge correctly of mines that change so suddenly from a 
soft, easily excavated rock to one of flinty hardness, and where, if the difficulty is great in the 
mine, it is increased ten-fold at the mill; for nothing short of the finest levigation can extricate the 
exceedingly fine particles of gold from these tenacious slates. So that, as a general rule, other 
things being nearly the same, the value of these “slate mines” will depend on the depth to which 
disintegration has proceeded. It is curious to observe how nearly the trap dykes of this region 
agree with the slates, which they intersect, as to the depth to which they are disintegrated: at the 
precise point where the slates become solid, there the dykes assume their true character, although 
above that they may have been nothing more than ferruginous earth. 
I first observed this interesting fact at Lawson’s mine, where a small dyke is exposed in the shaft, 
from top to bottom. At first it is, like the slates, a loose earth; a little lower, where they become 
more tenacious, it is a whitish wacke, that may be cut with a knife; still lower, where the slates 
resemble hornstone, the dyke becomes a true trap rock. 
At my second visit to this locality, Ezell’s mine was re-opened, and a shaft-sunk upon a dyke 
which, at first, was little more than a red earth, but soon exhibited its true character. 
