14 



Gibbes, Dr. Hume, of the Military Academy, and Dr. Burden, of 

 John's Island, were no mean helpers, and contributed largely to the 

 success of the work. In regard to the assistance given by Prof. F. S. 

 Holmes, Tuomey's own words are: "It would be impossible, if it 

 were necessary, for me to separate my own labors from those of 

 F. S. Holmes, Esq., both on the Ashley and in the post-Pliocene of 

 the State. His fine and valuable collections of fossils were placed 

 at my disposal, and I have used them without reserve. It is chiefly 

 through his labors that the Ashley has already become noted for its 

 organic remains." Tuomey assigned the Coastal Plain formations to 

 four classes or ages: Cretaceous, Eocene, Pliocene and post-Plio- 

 cene. We are at once struck by the absence of the Miocene from 

 this enumeration. He regarded the Miocene, now clearly established 

 about Darlington and Sumter, as Pliocene, and so put both Miocene 

 and Pliocene as Pliocene. In his map to show extent of formations 

 he uses the word Miocene for all that extent of territory which he 

 has carefully designated Pliocene in the treatise, but this is clearly 

 a misprint. 



The Cretaceous was traced, by means of characteristic fossils, 

 throughout the region described by Ruffin under the "Peedee Marl," 

 and in addition was found exposed in patches farther to the west in 

 Darlington and Florence counties along Lynches Creek to the mouth 

 of Sparrow Swamp, and farther to the east it was found on Little 

 Peedee River just where it is joined by Lumber River, and on the 

 Waccamaw, in Horry County, from three or four miles below Con- 

 way to within eight or ten miles of the North Carolina line. His 

 supposition was that the Cretaceous underlay that whole section of 

 country from its most western exposure at Sparrow Swamp on out 

 to and beneath the ocean. The Eocene was divided in this survey 

 into three groups : ( I ) The Buhrstone formation underlying the 

 calcareous beds described by Lyell and by Ruffin. The Buhrstone 

 was described as being 400 feet thick, its upper portion containing 

 silicified shells, being largely exposed up to the line drawn from 

 Columbia in a direction a little south of west by Lexington Court- 

 house and Aiken, on to Augusta, and its southern exposure running 

 in an irregular line across from Stout's Creek on the Santee to the 

 Lower Three Runs on the Savannah. (2) The Santee beds, the thick 

 beds of white limestone, marl and greensand, whose northern or 

 western exposures coincide with the line just given for the southern 

 limit of the Buhrstone. (3) The Ashley and Cooper beds, the newest 

 Eocene beds in the State, overlying the Santee beds just mentioned, 



