OF SOUTH CAROLINA. 141 
‘These underlying beds are best examined along the upper edge of the formation, where they are 
cut through by the rivers and streams. On the Savannah a good section occurs, at Silver Bluff, 
below the mouth of Hollow Creek; it is composed of beds of sand, and blue tenacious clay. I 
examined this locality with care, because it is one of those mentioned by Bartram, as Cretaceous, 
for he says that he found ammonites here. I found a bed of lignite a few miles up the creek, which 
is doubtless what he saw and described. Its dark color, so much like that of other Cretaceous beds 
of the State, deceived him. 
A bed of white clay underlies the lignite, which is three feet thick, very compact, and containing 
iron pyrites. In portions of the bed the structure of the wood no longer remains, it being reduced 
to a jet black homogeneous mass. ‘The superincumbent bed is twelve feet thick, and is composed 
of sand and gravel. ‘There are indications of this bed on other parts of the creek, but I could find 
no fossils in it, and from the identity of the mineral character of the associated strata, I must refer 
it to the Eocene of this region. 
At the ferry, below Augusta, a section of considerable height occupies the left bank of the river. 
It is made up of beds of clay and sand, the latter obliquely stratified, and presenting evidence of 
deposition from water violently agitated. Nearly all the sections among these beds present very 
striking proofs of having been deposited during alternating periods of repose and violence, for the 
sand and gravel are thrown up obliquely to the general planes of stratification, in a manner such 
as one may see on the coast, after a storm. These beds are followed by others, composed of clay, 
deposited in horizontal planes, evidently fine, sedimentary matter, once held in suspension, and 
thrown down in still water. Porcelain clay, or kaolin, mixed with grains of quartz, and scales of 
mica, the ruins of granitic rocks, form a large part of this bluff, and to these it owes its white color. 
At Hamburg, some high red cliffs, overlooking the town, belong to this formation. In the vicinity, 
a locality, known as the “Chalk Hills,” was pointed out to me, by Dr. Wray, of Augusta. The 
name of these hills is derived from the very fine beds of porcelain clay found there, which are over- 
laid by red loam and sand. he surface is very much broken and washed into ravines by the 
rains, and the alternating red and snow-white beds give the place a picturesque appearance. 
Among the beds of white clay I found crystals of hornblende, showing their origin to be the 
sienite, of which there is none found nearer than Abbeville. ‘The whole of these beds are obviously 
the remains of the granitic rocks, brought from above—the kaolin being derived from those abound- 
ing in feldspar. It appears also that the kaolin of many of these beds had been separated from 
the original granite, before their transportation hither, for I found interspersed rounded pieces of 
kaolin, evidently formed by the breaking up of previously existing beds. 
Nearly the whole of this region, known as the “ Sand-hills,” is underlaid by beds of this mineral, 
frequently of unsurpassed purity. Those near Hamburg are ten to fifteen feet in thickness. 
Similar deposits occur between Aikin and Graniteville, but of far greater extent, the beds being, 
in many cases, sixty feet thick. ‘They are, however, intermixed with bright red and yellow clays. 
For a mile in extent these beds may be traced in the ravines on the surface. The overlying sands 
are often washed away, and leave a series of bald, round and snow-white hills, relieved by an occa- 
sional stunted pine, or a clump of kalmias—often producing a pretty little picture amid the mono- 
tony of pine woods scenery. 
36 
