152 GEOLOGICAL SURVEY 
The locality below Tyler’s landing is but three or four miles from Johnson’s, or Binnaker’s 
bridge, which is the upper edge of the marl, on the S. Edisto, 
The bed of silicious clay is also found in Beaufort District, on Huspa Creek. It is hard, and of 
a dark gray color, and in every respect resembles menilite. On the surface it becomes white, the 
result of partial decomposition. 
I found no fossil shells here. ‘The superincumbent bed consists of sand, smooth pebbles of 
quartz, and water-worn nodules of white marl. The only organic remains that I discovered in this 
bed were some sharks’ teeth. 
The locality is altogether a curious one: the bed of the creek, at low water, is covered with this 
remarkable rock, apparently having no connection with the loose, incoherent materials with which 
it is associated, and yet, even in the absence of the evidence of organic remains, its physical charac- 
ters are so well marked that it must be referred to the Buhr-stone formation. 
Beds of pebbles and sand, with sharks’ teeth, are found at other localities in the District. A bed 
of green sand was also said to occur here ; and if I am right in referring the Huspa rock to the 
Buhr-stone formation, there is nothing against this; on the contrary, it is the position for it. But 
after a very careful examination of the localities around Pocotaligo and Huspa Creek, with the 
advantage of every facility and assistance, politely aflorded me by Walter Blake, Esq. I was unable 
to find any indications of such deposit. I did, indeed, see sand that was green, but it was not the 
green sand. 
I have been, perhaps, tediously minute, in describing and pointing out localities of that part of 
this formation which borders on the calcareous rocks; but it was because I deemed the determina- 
tion of the fact, as to its precise position, one of great practical value; and I think that I have now 
placed the matter at rest. Indeed had I not absolutely traced the Buhr-stone formation imme- 
diately under these beds, I would have been satisfied that that was its true position, after having 
seen beds two hundred feet in thickness, on the Congaree, as low down as McCord’s ferry, con- 
taining Eocene fossils, which it was impossible could have thinned out so suddenly as to overlie 
the marl on Stout’s Creek. 
It must be borne in mind that I include under the name of Buhr-stone formation, those beds 
described in the section at Aiken, consisting of sand, porcelain and common clays, grit, and sand- 
stone, as well as silicified shells, which, taken together, are 200 feet in thickness. 
As to the bed of silicified shells, or buhr-stone, which has given name to the formation, I con- 
sider it as merely the upper edge of the marl, in which, from peculiar causes, silica has taken place 
of the lime. Every thing in the aspect of this rock and its associated beds of sand, indicates a 
sea beach: the sands are thrown up and mixed with comminuted and broken shells, whilst here 
and there a bed remains undisturbed; and the embedded fossils show, very clearly, its littoral 
character. 
This rock, then, may rest upon the marl, at its upper verge, although I have not found it so in 
South Carolina, while the rest of the formation sinks beneath it. 
The stratum that I have called, for want of a better name, the silicious clay bed, must not be 
confounded with one somewhat resembling it, that is sometimes found on the marl. ‘There is no 
difficulty in distinguishing the two: the former is always more or less laminated, and is poor 
in organic remains. The bed of clay, associated with the marl, being deposited under similar 
