92 GOLD AND TIN DEPOSITS OF SOUTHERN APPALACHIANS. 
masses. Apparently this is another instance where descending, decomposing waters have 
found easiest passage along the same channel which gave to the original ore-bearing solutions 
their easiest ascent. 
In certain places solution has gone on to the extent of forming cavities or vugs in the 
rock. One of these, encountered in the underground workings at the west side of the 
main pit, is 3 feet wide, 15 feet long, and 20 feet high. The two greater of these dimensions 
lie in the plane of a zone of the white sand above described. 
The values of the ore mined in the early days can only be inferred from those known 
more recently; if what seems to be the general rule in this region applies to this particular 
mine, the first ore was considerably richer than that mined at greater depths. In their 
report in 1897 Nit?,e and Wilkens a state that the better grade of ore assays $5 to $7 per 
ton, while the average run of the mine is about $3. As a matter of fact the best ore has 
all been the decomposed, sandy material, or the residual nodules inside of it, with the one 
exception of a streak, near the southeast corner of the pit, of very siliceous rock which 
probably originally corresponded to the portions now decomposed, but which was so 
thoroughly sealed up by the siliceous cement that surface waters have not been able to 
penetrate it. At present only the sandy material is being sought for and the mining 
operations consist in gouging out and following the bodies of this character wherever they 
may lead. The resulting workings suggest and are indeed closely related in form to the 
honeycombed structure of much weathered limestone. It is said that under present con- 
ditions GO-cent ore can be put through the mill without loss, and $2 is about as good an 
average as can be obtained. In spite of the selection of the best ore, the grade of the 
ore is thus evidently decreasing, which probably indicates that the limits of the body 
from the standpoint of economy are being reached. Nitre's sketch plan of the mine,b 
which shows the unsiliciiied rock (mapped as granite) closing in on all sides, seems likewise 
to indicate that the limits of the ore are not far beyond the walls of the present cuts and 
stopes. It is not improbable, however, that other ore bodies, perhaps connected with the 
main deposit by comparatively narrow strips of profitable ground, might be discovered 
by more careful prospecting than has apparently been done. It seems, in fact, that the 
smaller pit is on such an ore body rather than on the same one as the main pit exposes. 
BLACKMON MINE. C 
The Blackmon mine, situated in Lancaster County, S. C, a little northwest of White 
Bind' post-officer and about 14 miles north of Kershaw, has also been known since the early 
days of gold mining in this region. It is the property of the Piedmont Mining and 
Development Company, of Charlotte, N. C, and Mr. O. J. Thies is manager. 
L T ntil recently the mine has been idle for many years, although at one time considerable 
ore was taken out from an open cut.d Since the resumption of work all operations have 
been conducted underground. A shaft started in the hanging wall goes down vertically 
for 113 feet, where it reaches the foot wall and continues as an incline at about 40° to a 
point 180 feet from the surface, measured vertically. Drifts and crosscuts, probably 
amounting in all to 600 feet, have been run at the 80-, 11 3-, 153-, and 180-foot levels. The 
surface improvements consist of a 20-stamp simple amalgamation mill and a shaft house, 
with steam hoist and compressor. 
The geology in this vicinity is much obscured by decomposition and by vegetable growth. 
While the rock relations are fairly plain in the mine, their significance is not so readily 
grasped. A body of extremely foliated sericite schist which strikes northeasterly and dips 
30° to 70° NW. is cut by a porphyritic rock, also somewhat foliated, which lies to the 
southeast and has followed the planes of foliation of the schist. Both of these are crossed 
by a dike of diabase which has a northwesterly strike and dips steeply. 
a Bull. North Carolina Geol. Survey No. 10, 1897, p. 144. 
b Nitze and Wilkens, op. cit., p. 146. 
c Formerly known as Blaekman's mine; cf. Tuomey, M., Rept. Geol. and Agr. Survey, South Carolina, 
1844, p. 23. 
d Tuomey, M., Geology of South Carolina, 1848, p. 95. 
