28 Phosphate Rocks of South Carolina, 
have been derived from an older formation, viz : 
the Eocene Marl, or the ‘Great Carolinian Bed 
of Marl,” which is the foundation of the whole sea- 
board country of South Carolina, and as represented 
in Plate I, is composed of the Santee, Cooper and 
Ashley River Marls, which in the aggregate are 
seven hundred feet thick, and extend from North 
Carolina into Georgia. Before the low country of 
South Carolina was raised above the level of the 
Ocean, the waves of the Atlantic beat upon the 
granitic hills of Edgefield, Lexington and Richland. 
The shallow water of the coast with its submarine 
formation of undulating sand-banks was then, as now, 
resting upon this surface of the great Marl formation, 
of Eocene age; both were below the level of the 
Ocean, (see Plate II,) exposed to the degrading influ- 
ence of its waves, and bored by Mollusca and other 
marine animals, as represented in the diagram. 
Examine this Plate II; it speaks for itself. The 
Eocene Marl is here represented as we have found it, 
with its surface washed into deep cavities and holes, 
bored by the animals just named and honey-combed 
to the depth of five or six feet. This is its condition 
off Charleston harbor at the present time; and wher- 
ever the surface of the bed inland has been uncovered, 
it is found irregular and broken, and the Phosphate- 
rocks show this plainly. From the coarsely honey- 
combed surface of this mother-bed, fragments were 
being continually broken off by the waves, rolled over 
the sand-beds, which wore off their angular edges, 
and finally deposited them in extensive masses in 
