AMERICAN GEOLOGY DECADE OF 1840-1849. 407 



mining - of sand and mud flats on which they grew and the consequent 

 settling of the stumps, retained in an upright position by their wide- 

 spreading roots, and not to a subsidence of the coast, as taught by 

 Lyell, Bartram, and later by Lieber and Cook." The origin and nature 

 of the soils, the mining and preparation of fertilizers, including lime 

 burning, the washing and milling of gold ores, and kindred subjects, 

 were touched upon. Many soil and fertilizer analyses were given, the 

 latter and their discussion being largely by Prof. C. U. Shepard, then 

 professor of chemistry in the Medical College of the State, at Charles- 

 ton. The fossils were identified by Conrad and Gibbs. 



It is but natural that a considerable portion of the work should be 

 given up to a discussion and description of the Tertiary deposits, which 

 cover more than half the area of the State. Concerning these he 

 recapitulated as follows: 



1. That they are situated in a vast depression in the Cretaceous rocks, which, 

 however, are only visible on the east and northeast. 



2. That the Eocene consists of three well-defined groups: (1) The Buhr-stone 

 formation, composed of thick beds of sand, gravel, grit, clay, and buhr-stone, amount- 

 ing to at least 400 feet in thickness and underlying the calcareous beds. Its upper 

 portions are characterized by beds abounding in silicified shells, for the most part 

 identical with the Claiborne fossils. As these are littoral shells, they probably 

 occupied the coast while the Santee beds were forming in deep water. The materials 

 of which this formation is composed are the ruins of the granitic and metamorphic 

 rocks of the upper districts, which may often be traced to their origin. (2) The 

 Santee beds, consisting of thick beds of white limestone, marl, and greensand. 

 These are best seen on the Santee, where, interstratified with the greensand, they 

 dip gently toward the south. The coralline marl of Eutaw is found near the upper 

 edge of these beds. (3) The Ashley and Cooper beds, which are the newest Eocene 

 beds of the State. The marl of these is characterized by its dark gray color and 

 granular texture, while the remains of fishes and mammalia give its fossil remains a 

 peculiar character and leave no doubt of the position assigned it — at the top of the 

 Eocene series. These, together with the Santee beds, must amount at least to a 

 thickness of 600 or 700 feet, 



3. That although these strata contain throughout characteristic Eocene fossils, yet 

 they also inclose some Cretaceous forms. 



4. That the Middle Tertiary of the State, composed of beds of sand and mail, 

 highly fossiliferous, is scattered, like similar beds in other places, over the Eocene 

 and Cretaceous formations in isolated patches. That the proportion of recent species 

 increases toward the south, and that the extinction of species seems to proceed in 

 that direction, as is proved by the fact that the recent forms, which are also fossil, 

 belong to a more southern fauna, there being but one or two exceptions. 



5. That in South Carolina the proportion of recent species in this formation amounts 

 to 40 per cent. I have, therefore, referred it to the older Pliocene. 



6. That the post-Pliocene is confined to a belt along the coast of about 8 or !» 

 miles in breadth. The fossils are nearly al»l referable to living species now inhabit- 

 ing the coast; a few, however, belong to the fauna of Florida and the West Indies. 

 An elevation of the coast has taken place since the deposition of these beds, which, 

 it is probable, has given the rivers of the Atlantic slope a w r estern tendency. 



"Tuomey's view wasupheld by Prof. N. S. Shaler as recentlyas 1870. Proceedings 

 of the Boston Society of Natural History, XIII, p. 22S. 



