Jfesozoic and Coinozoic Geology and Palaeontology. 265 



3. Next in order above the Santee beds, are the Ashley and Cooper 

 beds, which are the newest Eocene beds of this State. The marl of 

 these is characterized by its dark gra}^ color and granular texture, 

 while the remains of fishes and^mammalia give its fossil remains a 

 peculiar character. These, together with the Santee beds, have a 

 thickness of from 600 to 700 feet. 



Artesian boring has shown that the Ashley marl occurs at a depth 

 of about 300 feet, at the City of Charleston. 



The Eocene is succeeded, in South Carolina, by isolated patches of 

 highly fossiliferous beds of sand and marl, in which Tuomey estimated 

 the proportion of living species to amount to 40 per cent, and for this 

 reason referred the beds to the age of the Older Pliocene. On the 

 Waccamaw and Peedee, this older Pliocene is found super-imposed 

 upon Cretaceous rocks, and, in general, the strata appear to have 

 been deposited on a plane that rises gently from the Atlantic till it 

 reaches its greatest elevation in Darlington district. The protected 

 patches may be traced, at short intervals, from Horry to Darlington, 

 and from thence by Lynch' s creek to Sumter. It occurs on Cooper 

 river, and at various other places. 



The Post-pliocene, of South Carolina, is confined to a belt along the 

 coast of about 8 or 9 miles in breadth. The fossils are nearl}^ all re- 

 ferable to living species now inhabiting the coast ; a few, however, 

 belong to the fauna of Florida and the West Indies. There appears 

 to have been a slight elevation of the coast during this period. 



T. A. Conrad* separated the Eocene into the Upper or Newer Eocene, 

 found at Vicksburg, Miss., and including the white limestone of St. 

 Stephens, and of Claiborne, Ala., and part of that in Charleston county, 

 South Carolina, characterized by Scutella lyelU, 8. rogersi^ Pecten 

 povlsoni, and XummuUtes mantelli\ and the limestone in the vicinity 

 of Tampa bay, Florida, characterized by NummuUtes Jloridana, C^Hs- 

 tellaria rotella^ and Ostrea georgiana ; and into the Lower or Older 

 Eocene, consisting of the fossiliferous sands of Claiborne, and St. 

 Stephens, Ala., of the Washita river, near Monroe, La. ; of Pamunk}^ 

 river, ■ at Marlborne, and the greensand on James river, below City 

 Point, Va., and at Fort Washington, Piscataway, and Upper Marl- 

 borough, Mar3^1and, characterized by Cardita pla7iicosta^ C. blan- 

 dingi, Crassatella alta, Ostrea seUaformis, and Turritella mor- 

 toni. He described,* from the Eocene, in the vicinity of 

 Vicksburg, Mississippi, Dentalium mississippiense^ Fissurella mis- 



■■' Proc. Acad. Nat. Sci., vol. iii. 



