119 



CHAPTEE IX. 



CARBONIFEROUS SERIES. 



CARBONIFEROUS EOCKS. In the south and middle of 

 England, the Carboniferous rocks consist chiefly of 

 Limestone at the base and Coal-measures above. In- 

 cluding the South Wales, the Forest of Dean, the 

 Somersetshire and other areas, a typical section of the 

 beds is as follows : 



Feet. Feet. 



Coal-measures 1,000 to 12,000 



Millstone grit 500 , 1,000 



Yoredale rocks 100 



Carboniferous or Mountain Limestone . 500 

 Carboniferous Limestone shale . . .100 

 Yellow Sandstone with plants, Ireland, &c. 100 



1,000 



2,500 



500 



200 



Generally resting on Old Red Sandstone. 



The Yellow Sandstone beds often form a passage 

 from the Old Eed Sandstone to the Carboniferous rocks, 

 and the plants have carboniferous affinities. The ac- 

 companying shales in Pembrokeshire and elsewhere, 

 contain numerous fish-teeth, Spirifers, Productas, and 

 a few Lingulas ; and the Carboniferous Limestone, 

 which is more than 2,000 feet thick in South Wales, 

 and in Somersetshire, is so highly fossiliferous that it 

 may be stated that the whole of the limestone once 

 formed parts of animals. The lowest 500 feet consists 

 chiefly of fragments of Encrinites. The Yoredale rocks 

 of Yorkshire have no precise lithological parallel in 



