384 PALAEOZOIC TIME. 



6. Tennessee Section. 



Lower Silurian. 



Potsdam, Potsdam Epoch. — " Chilhowee" sandstones and sandy shales, at least 

 1000 feet in east Tennessee. 

 Calciferous Epoch. — Fine sandstones and shales, with magnesian lime- 

 stone : sandstone member (lowest), 600-1000 feet in east Tennessee; 

 shales, 1500-2000 feet; limestone, 3500-3800 feet. 



Trenton, Trenton Epoch. — " Stones River" blue and dove-colored limestones, 

 with more or less chert, 500-600 feet in east Tennessee; lower part 

 of "Nashville Group." 



Hudson, Utica and Hudson Epochs. — Upper part of "Nashville Group," calca- 

 reous shales and argillaceous limestones, including beds of fine marble, 

 1000-2000 feet in east Tennessee. 



Upper Silurian. 



Niagara, Medina Epoch. — "Clinch Mountain" white and gray sandstone, and 



"White Oak Mountain" brown sandstones and shales, 800-1000 feet. 



Clinton Epoch. — " Dyestone Group," variegated calcareous shales with 



some sandstone, 200-300 feet in east Tennessee. 

 Niagara Epoch. — " Sneedville" gray limestone, 200 feet thick. 

 Lower Helderberg. — Gray crinoidal limestone, 75-100 feet in middle Ten- 

 nessee ; absent elsewhere (?). 



Devonian. 



Hamilton (?), Genesee Epoch. — " Black Slate," a brownish-black slate, often 

 pyritiferous and bituminous, 100 feet or more in east Tennessee. 



Carboniferous. 



Subcarboniferous, Lower. — " Siliceous Group," shales and sandstone, 400 feet 

 at Cumberland Gap (perhaps Upper Devonian) ; blue and gray lime- 

 stone, mostly cherty, with some shale, 300-550 feet. 

 Upper. — " Mountain" limestone, blue, thick-bedded, and in great part 

 oolitic, 500-750 feet in middle Tennessee. 



Coal Measures. — Sandy conglomerates, sandstones with six or more coal- 

 beds, and shales, 2500 feet or more in middle Tennessee. 



In the Eastern border region, about the Gulf of St. Lawrence (which 

 was probably an interior basin like the Interior Continental) there 

 were limestones forming almost continuously from the Calciferous 

 epoch in the Lower Silurian to the close of the Clinton epoch in the 

 Upper Silurian, which is the last of the formations there observed. 

 With regard to other parts of the Eastern border region our know- 

 ledge is yet imperfect, and in great measure because the crystalli- 

 zation which the rocks have undergone has obliterated most of 

 their original features. This is the case over New England and the 



