OF SOUTH CAROLINA. 151 
on the road, towards the foot of the hill. It seems, at this point, to be associated with beds of sand, 
and, as usual in such cases, every particle of carbonate of lime is removed, although a few hun- 
dred yards lower, it is mixed with calcareous particles, in considerable quantity. 
Gates’s quarry, in this neighborhood, is a noted locality of buhr-stone, where the rock has been 
procured for economical purposes. 'The buhr-stone is about four feet thick, rests upon a stratum of 
sand and clay, and although the fossils are very numerous, it is not easy to make them out: I 
found, however, Cardita planicosta and Crassatella aleformis, pretty well characterised. A bed of 
dark colored sand underlies the whole, and is exposed in the bed of a small stream below the 
quarry. 
Following the outcrop of the calcareous rocks to Cawcaw Swamp, about three miles from 
Orangeburg Court House, we found the finest locality in the State, of the Buhr-stone formation, so 
far, at least, as its fossils are concerned. As high up the swamp as Poosei’s silicified shells are 
found; but they occur at Legare’s mill in greatest abundance and perfection. 'They are embed- 
ded in red loam, which is enclosed in whitish clay, at an excavation made near the mill-pond. 
‘The red loam in which the fossils are embedded presents the appearance of having been rolled, very 
much as we have seen balls and cylinders of clay moved backwards and forwards by the waves, 
on the coast, and attaching to themselves whole and comminuted shells. 
The section at the mill, in the descending order, is as follows: Eight feet, sandy, whitish loam 
and clay, containing masses of red loam with fossils; two feet, greenish clay ; four feet, white sili- 
cious clay, containing casts of Cardita planicosta and Lutraria lapidosa. When the excavations 
are washed by rains the fossils are detached from their matrix, and may be collected in great num- 
bers. On the road side, where the swamp is crossed, red loam is again exposed, and here also a vast 
number of well preserved fossils may be collected. From these two localitities on Cawcaw Swamp, 
nearly all the fossils in the appended list were procured. 
The red and yellow loam appears at the surface, nearly all the way, but the junction of the 
buhr-stone with the marl, in the village, is not seen. 
The formation is again exposed on S. Edisto. On Goodman’s Swamp a bed of quartzose rock is 
quarried, for mill-stones; and on Dean’s Swamp the buhr-stone shows itself, at some height above 
the swamp. Near the mill, on the road, lower down, it is again laid bare, and shells and casts are 
found, composed of quartz that is almost transparent. wk 
The buhr-stone rises fifteen feet above the surface, at Stroman’s mill, on Rocky Swamp. 'The 
section at this place is nearly the counterpart of Gates’s quarry. It consists of five feet of buhr- 
stone, underlaid by three feet of fine, deep-yellow sand, which rests upon a bed eight feet thick, 
composed of red clay and silicified shells. The strike of the bed, at this place, is N. 20° E. and 
the dip about 15°. Below the surface there is a thick stratum of clay, containing pieces of wad, or 
impure oxide of manganese. At the mouth of the swamp a thick bed of white, silicified shells 
occurs: the shells have all the appearance of being carbonate of lime, although they contain not a 
particle of that substance. The common Eocene fossils abound in it. 
At Tyler’s Landing, on the Edisto, about one mile below Willow Swamp, the silicious clay bed 
is found on the left bank of the river, cropping out in thick layers; and a little higher up the 
swamp, near the bridge, the buhr-stone is seen crossing the road. A portion of the bed is converted 
into red and brown jasper. | 
