140 Permian Strata. 



the Vale of Eden, in the north, only a few thin beds 

 of Magnesian Limestone lie in the middle of red 

 sandstones and marls. Hard and fast lines of division 

 by no means hold good in this case. 



The Permian strata were for long considered as form- 

 ing a lower part of the New Red Sandstone, till separated 

 from it by Professor Sedgwick, in his celebrated Memoir 

 on the Magnesian Limestone. They were afterwards 

 called Permian by Sir Roderick Murchison, from the 

 ancient Government of Perm in European Russia, 

 where they are extensively developed. 



Between the neighbourhood of Nottingham and 

 Tynemouth in Northumberland, they have been sub- 

 divided by Professor King, into 



Crystalline and other limestones. 

 Brecciated limestone. 

 Fossiliferous limestone. 

 Compact limestone. 

 Marl slate. 



The Marl slate lies at the base, but these sub- 

 divisions are by no means constant, and the lines 

 between them are not always definite. In many places 

 the rock consists of round masses of all sizes, often as 

 large as good-sized cannon balls, all cemented together. 

 The section is finely exposed on the sea -cliffs between 

 Hartlepool and South Shields, with great outlying 

 masses of rock rising out of the sands like ruined 

 castles, pierced by caverns with lofty ragged pillars and 

 arches, worn out by the restless sea, and through which 

 the daily tide flows. In their range from Nottingham 

 to this district the Magnesian Limestone is inter- 

 stratified with three minor beds of red marl. 



In Nottinghamshire the position of these Permian 

 strata to the underlying Coal-measures, and the over- 



