176 GEOLOGICAL SURVEY 
Fossils are scarce in the lower, soft bed, where alone they can be extricated. I could only 
identify the following. 
Fissurella redimicula, Chama congregata, 
Dispotea ramosa, a arcinella, 
Oliva litterata, Venus alveata, 
Pyrula carica, Artemis acetabulum, 
Fusus quadricostus, Solecurtes caribeus, 
Panopea reflexa, Lutraria canaliculata, 
Pecten Peedeensis, Cardium magnum, 
“ — Mortoni, Modiola Dueateli, 
et eboreus, Cardita tridentata. 
‘ septemnarius, 
At Witherspoon’s Bluff, about two miles higher on the river, the Pliocene marl is seen rising 
from the water’s edge, in a bed ten feet thick, the upper portion of which is more silicious than the 
rest. The only fossils found here are Modiola Ducateli, and Panopea reflera. 
The position of these beds, as well as those on the Waccamaw, shows that they were deposited 
on the very uneven surface of the Cretaceous rocks. At Giles’s Bluff the lower bed of marl is 
twenty feet above the river, while at this locality it is level with it. A difference of level of about 
ten feet occurs on the Waccamaw, in an equally short distance. 
The marl is covered by a thick bed of sand, showing diagonal bedding. This is the highest 
point, on the Peedee, at which the Tertiary has been seen. 
Leaving the river and proceeding towards Darlington Court House, mar! of this formation occurs 
at wide intervals. First at Mr. Cannon’s, near Black Creek, where the bed is a thick, calcareous 
mass, only exposed in an artificial excavation, and containing but few fossils, among which I could 
only distinguish Balanus proteus and Petricola pholadiformis. 'The country between Black Creek 
and Lynch’s Creek is level, and much covered with swamps, and hence there are but few natural 
exposures of marl. 
At Mr. F. Williamson’s a similar bed has been discovered, which is also below the surface, and 
requiring a considerable excavation for its exposure. I found here, 
Fulgur carica, Pectunculus subovatus, 
“  perversus, : Pecten eboreus, 
Voluta mutabilis, Arca transversa, 
Fusus quadricostatus, Cardita granulata, 
Oliva litterata, O. disparilis, 
Trochus philantropus, O. Virginiana. 
Mitra Caroliniensis, 
Both here and at Cannon’s the marl is rich, containing 70 per cent. of calcareous matter. 
Not far from this, marl is found, at a natural exposure, at Mr. Fountain’s, but it was difficult to 
ascertain its thickness. The fossils on the surface, however, were sufficiently numerous and char- 
acteristic to show that it was Pliocene. It rests, as in other parts of the District, on the black 
shale of the Cretaceous formation. - 
