1889. ] NEW YORK ACADEMY OF SCIENCES. 143 
side a small vein of quartz. Following this fissure, it becomes 
a simple vein and again assumes distinctly a banded structure. 
When we consider the extent of territory occupied by this 
tin formation, its great length, and the thickness of the veins, 
it is natural to conclude that somewhere along this line there 
should be deposits of value. Examining the entire field, I have 
become convinced, although it is possible to be mistaken, that 
from near Lincolnton, N. C., to about Black’s Station, S. C., is 
that portion where valuable deposits are most likely to occur. 
The best part is probably from King’s Mountain village, some 
two miles to the northeast, and five or six miles, possibly seven, to 
the southwest. Myreasonis this: In the first place, in and near 
the village of King’s Mountain larger pieces of cassiterite have 
been found than anywhere else. Some pieces gathered on the 
surface have weighed as much as two pounds. Without any 
difficulty, one can pick up specimens of cassiterite anywhere 
from the village to a distance two miles northeast and about 
five miles southwest. 
When we remember that these tin deposits, if I am correct, rep- 
resent the youngest period of time there, viz., the vein-making 
period, following as it does that represented by the trap dikes, 
I think we may fairly suppose that the forces of nature were 
not severe in their action when the veins were forming. 
Therefore I doubt whether any very great amount of erosion 
has taken place since the tin veins were formed, and believe 
rather that the great period of erosion preceded the formation 
of those veins. Again, in regard to surface disintegration, the 
evidence is that since the tin veins were formed there has been 
comparatively very little of it. The decomposition or surface 
change apparent is mostly in place to-day,—7.e., it has not been 
eroded and carried off. This is conclusively proved by beds of 
kaolin in place, and by veins of quartz also, in the clay which 
was slate. Both Lyell and Agassiz note precisely the same oc- 
currence. Again, the forests with their carpetings must be 
remembered as a protection. 
I think that these tin veins are due also to the action of water; 
that is, that water was the great agent in their deposition. It 
would seem that in getting nearer the surface or to the top of 
the slates, which become firmer and more crystalline as depth is 
attained, there was greater room for expansion, and that the 
capping of the veins found greater room for deposition near the 
surface of the formation, whereas deeper down they were con- 
fined entirely between the walls. 
Again, when we take into account the fact that greisen lodes 
occur in the trap, and that we find a distinct fissure, filled with 
greisen, cutting the trap formation in two, it appears to me that 
