REPORT OX THE PHOSPHATE FIELDS OF SOUTH CAROLINA. O 
Shepard, published by Chazal. 1 shows the various strata and their 
content of phosphoric acid. 
Table I. — Thickness and character of strata in phosphate regions of South. Carolina as 
determined from a ■ 
Character of stratum. 
r, ., , Content of 
E quivalent 
in bone 
phosphate 
of lime. 
Clay 
Phosphatic nodules . 
Marl 
Do 
Argillaceous marl . . 
Phosphatic nodules 
Argillaceous marl. . 
Do 
Phosphatic nodules . 
Do 
Argillaceous marl » . 
Phosphatic nodules. 
Hard marl 
Argillaceous marl. . . 
Do 
Do 
Do 
Phosphatic nodules 
Argillaceous marl 
Marl and phosphatic grains. 
Argillaceous marl 
Sand v marl 
Do 
Hard marl 
Phosphatic pebbles 
Hard pebbly marl 
Sandy limestone 
Firm limestone 
Sandv limestone 
Feet. 
17- 20 
26- 30 
26- 30 
34 
46 
70 
85 
90 
104 
110-112 
110-112 
125-128 
125-128 
145 
170 
22 s 
255 
280 
286 
287-290 
Per cent. 
0.42 
26.79 
3.07 
3.01 
2.03 
22. 72 
1.26 
1.51 
13.38 
23.60 
10.65 
15. 81 
1.23 
Traces. 
Traces. 
Traces. 
Traces. 
22.47 
.60 
Per cent. 
0.92 
58.48 
6.70 
6.57 
4. 43 
49.59 
2.74 
3.30 
29.20 
51.52 
23.24 
34.91 
- i 
300-305 1 
3.37 
305-306 
.90 
307 
.80 
309-311 
.63 
312-313 
27. 72 
312-313 , 
2.47 
31-5-316 
1.02 
321-322 
.95 
323 
1.05 
49. 05 
1.31 
13.01 
7.37 
1.96 
1.75 
1.37 
60.52 
5.39 
2.22 
2.07 
2.29 
1 Including phosphatic nodules. 
PHYSICAL AND CHEMICAL PROPERTIES. 
The South Carolina phosphates occur in nodules varying from the 
size of sand grain- to bowlders weighing several tons. The rock 
varies in hardness and texture from soft porous material to hard, 
lustrous, flintlike pieces. The nodules are sometimes smooth 
rounded or kidney shaped, closely resembling " coprolites." but more 
often they are irregular in shape, pitted, or completely perforated, 
the holes usually being filled with sand and clay, which has to be 
removed by washing. In color the rock varies from grayish white 
to almost jet black, and between these two extremes there are a 
variety of shades of red. yellow, and brown. 
The River Rock and that found in the marshes is usually darker in 
color than that found farther inland, owing probably to a larger 
percentage of organic matter. The rock varies in specific gravity 
from 2 to 2.5: and from a large number of determinations made by 
Shepard the average is 2.4. The nodules are usually denser and 
harder on their surface than in the interior, but this is not always so. 
: ketch of the South Carolina Phosphate Industry, p. 26 (1904). 
