81 



curacy by the lino drawn by tyr. Maclure for the boundary of his 

 Alluvium, through Fredericksburg, Richmond, Petersburg, &c. 



Ill- South Carolina, I have traced the formation in question, as 

 mentioned in the introduction, at Vance's Ferry on the Santee 

 river, in Orangeburgh county, my means of a fine series of fossils, 

 collected by my friend Dr. William Blanding, who also found in 

 the vicinity a Jjeleinmte imbedded in limestone, (Upper division of 

 the cretaceous group, Morton) which constitutes the prevailing, 

 and indeed, almost the only formation between Vance's Ferry and 

 Charleston. At the former place then, we find the Eocene superim- 

 posed upon the Cretaceous strata, and capped by a superficial de- 

 posit of Older Pliocene sands. The latter have been discovered 

 also near the junction of the Congaree and Wateree rivers, a dis- 

 tance of seventy-five miles, in a direct line, to Hull's Bay the near- 

 est point on the coast. 



From Vance's Ferry, the line of the Eocene runs a little to the 

 south of west and passing through the town of Orangeburgh, cross- 

 es the Savamiiih river at Shell Bluff which is its boundary on the 

 west. This formation appears at intervals, in a distance of forty 

 miles, following the course of the river.* Shell Bluff, according to 

 the observations of Mr. Vanuxem, is "seventy feet high, formed of 

 various beds of impure carbonate of lime." The Ostrea Georgi- 

 ana is here "in a bed nearly six feet in thickness in the upper 

 part." A deposit of the same kind of oyster shells occurs near 

 Milledgeville in Georgia, accompanied by the Scutella quinquefa- 

 ria : (Say) imbedded in a white, friable limestone. Three parallel 

 ridges of these oyster shells are said to run from the Savannah to 

 the Alatarnaha river. 



The Eocene is extensively developed in Early county in the 

 form of sandstone with silicified fossils, corresponding with a rock 

 in the vicinity of Claiborne, Alabama, the dark surface of which 

 is paved, as it were, with beautifully translucent silicifiod shells. 

 Dr. N. Jones, of Mobile, remarks, that at Fort Gaines, on the 

 Chattahochie, a bluff occurs more than one hundred and fifty feet 

 in elevation, the close resemblance of which to the Claiborne es- 

 carpment is very striking, it is certainly of the same ago as the 

 latter. 



At Claiborne, 1 have had the best opportunity of investigating 

 the organic remains and superposition of the Eocene strata. The 

 escarpment, or bluff, facing the Alabama river at Claiborne, is, at 



*Vide Appendix to Cuvier's Theory of the Earth " by Dr. Mitchell. 



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