METAMORPHIC ROCKS. 
19 
hales or other argillaceous rocks. They are associated with beds of manganese oxide and 
feaphite and may represent deposits in comparatively shallow water. 
A beautiful deep-green rock, which resembles a talc schist, forms the wall rock of the 
Slackmon mine in Lancaster County. In places the green color gives way to a silvery gray 
ind pink, suggesting mother-of-pearl. This rock is almost completely made up of exceed- 
ngly fine fibers of sericite and contains, in addition, a few small dark-red garnets. It is 
>robably a sediment much altered by regional metamorphism and by an intrusion of 
>orphyry which has penetrated it. 
LIMESTONE. 
The limestones of this area can hardly be called schists, but they have been subjected to 
he same forces of metamorphism as the surrounding rocks and in many places, particularly 
lear the limits of the beds, they are foliated and composed of other minerals in addition 
o calcite; in such places they possess a truly schistose appearance. These limestones are 
ather magnesian; the upper portion of the beds is in places too high in magnesia to make 
ime, and is practically a dolomite. The dolomitic portions are usually light gray to white 
n color and the more calcareous varieties are generally blue. The quarry men are pleased 
o find " blue rock," while the white they speak of as " dead." Below are given the analyses 
if some typical limestones of this area, which the writer owes to the courtesy of Dr. Earle 
>loan, State geologist of South Carolina: 
Analyses of typical limestones. 
1. 
2. 
3. 
,i0 2 
0. 71 
.23 
.47 
1. 16 
54.24 
.02 
.01 
.02 
Trace. 
Trace. 
43. 27 
.11 
1.28 
.23 
.47 
5.60 
48. 66 
.08 
.01 
.06 
Trace. 
Trace. 
43.52 
.12 
1. 16 
U 2 3 
.96 
4gO 
25.48 
}aO 
30.50 
s[a 2 w 
C 2 
I 2 at 100 
.03 
ri0 2 
3 2 0-, 
jo 2 . 
8 ""t>" '"' 
100. 24 
100. 03 
All these specimens are from near Gaffney. No. 1 represents very pure limestone; No. 2 
ndicates a rock that is somewhat less pure, but makes very good lime; No. 3 is a partial 
malysis of a magnesian or dolomitic phase, which is not burned for lime. 
Mineralogically, these rocks consist principally of granular carbonate, whether calcite 
)r dolomite can not be told by means of the microscope. Small lenses and bunches of 
piartz, probably introduced at the time of the metamorphism of the region, occur in some 
specimens. A little colorless amphibole, probably actinolite, and thin blades of a colorless 
)r whitish mineral, presumably wollastonite, are rather commonly observed. At the edges 
>f the limestone masses the rock passes over within a short distance, yet by gradations, into 
:he adjoining rock — feldspathic quartzite in some places, quartz-biotite schist in others. 
The limestones are known to occur at numerous points through practically the whole 
jxtent of the Kings Mountain Range. A good view of the limestone in one of the quarries 
it Gaffney is shown in PI. II. 
