68 Review of M. Tuomey s Final Report 



the granite, the gneiss, and the clay slates of this region. Along 

 this line too, are found the first falls in ascending the rivers caused 

 by the tertiary which come in contact with the harder rocks, be- 

 ing washed away. 



One striking fact mentioned in relation to this boundary is the 

 change observable in the botanical features of the country in 

 crossing it. The Pinus americanus here finds its inland limit, and 

 the common grass of the pine woods of the genus Aristida, here 

 gives place to the brown grass ( Andropogon) of the higher lands. 



Eocene. — The eocene deposits are represented as occupying a 

 deep depression of the cretaceous strata, which latter are observed 

 only in the northeastern section of the state where they sink 

 beneath the tertiary rocks, not to appear again at the surface ; 

 though undoubtedly underlying the vast beds of a later period, 

 which in this region are seen to rest upon them. 



The eocene strata Mr. Tuomey describes as occurring in three 

 well marked groups. The Burr-stone, the Santee beds, and the 

 Ashley and Cooper beds. 



The Burr-stone formation, the oldest of these eocene strata, 

 is extensively developed at numerous localities, and is made up of 

 sandstone, clay, beds of gravel and sand, and silicified shell or 

 burr-stone ; which last gives its name to the whole group. The 

 relative position of these deposits and the calcareous rocks of 

 the Charleston basin, has been a matter of some question, but 

 Mr. Tuomey has settled the point, having traced the burr-stone 

 beds, under those of the calcareous rocks. 



The fossils of this group are numerous, and a list is given of 



53 species Gasteropoda, 30 species Lamellibranchiata, and three 

 or four undescribed species of corals are mentioned as occurring 



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together with leaves of exogenous plants of the genera Quercus 

 Fag us and Salix, and some remains of Crustacea. 



The predominance of Gasteropods among these fossils indi- 

 cates, says Mr. Tuomey, the littoral character of the formation, 

 and he draws the inference from this fact and from the existence 

 of land shells and remains of plants, among the fossils, " that the 

 whole group was deposited on the coast of the eocene sea." This 

 formation it will be seen by reference to the map, has its principal 

 development at the surface in the districts of Orangeburg and 

 Lexington. 



The Santee beds or Calcareous Strata of the Charleston basin 

 occupy a large area of the surface of the state south of the San- 

 tee, and have been called the Carolina bed, because of their great 

 development in the state. They outcrop at numerous localities 

 along the right bank of the Santee, also along the southern line 

 of the burr-stone between the Santee and the Savannah, and on 

 the Savannah. These deposits consist of beds of thick white 

 limestone, marl and green-sand. 



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