2IO NEW RED SANDSTONE. 



times when the sea had access to the area, but on the whole 

 the New Red Sandstone was deposited when the physical 

 conditions were somewhat similar to those of the Old Red 

 Sandstone. 



The red colour of the rocks is in many cases due to the com- 

 ponent materials being coated with films of peroxide of iron during 

 the formation of the beds. The deposition of iron-ore in this form 

 is not known to take place in modern marine accumulations, but 

 instances occur in some of the Swedish lakes. Hence the red 

 colouration, taken in conjunction with the occurrence of gypsum 

 and rock-salt, helps to confirm the view that the New Red rocks 

 were formed in lacustrine areas. 



Evidences of Glacial action during Permian times have been 

 brought forward by Sir A. C. Ramsay, but they have been 

 questioned. (See sequel.) ^ 



The New Red Sandstone series in the northern and midland counties of England 

 was traced out on the Geological Survey Maps, chiefly by Mr. H. H. Howell, 

 Prof. E. Hull, Mr. J. G. Goodchild, Mr. T. V. Holmes, Mr. C. E. De Ranee, 

 and Mr. A. Strahan ; in the south-west of England the rocks originally surveyed 

 by De la Beche and others, have been re-mapped in detail chiefly by Mr. W. A. 

 E. Ussher, 



PERMIAN OR DYAS. 



The name Permian was proposed by IMurchison in 1841, from 

 the ancient kingdom of Permia, in Russia. 



In England the Permian rocks consist of red sandstones, con- 

 glomerates, marls, and magnesian limestones, of which the following 

 series is generally established : — 



Durham. Yorkshire. 



l' Upper Red Marl and Sandstone. 

 50 feet. 

 Upper Magnesian Limestone. 



120 feet. 

 Middle Red Marl, Sandstone 



and Limestone. 200 feet. 

 Lower Magnesian Limestone. 

 ^ 120 feet. 



Lower Permian ) White or yellow false-bedded sand (Quicksand), with oc- 

 (Roth-liegende?). / casional seams of breccia. 20 feet or less. 



Red Sandstone and Marl. 

 Upper Permian I 50 feet. 

 or Magnesian J Magnesian Limestone. 

 500 to 600 feet. 

 Marl Slate (Kupfer 

 Schiefer). 10 to 60 feet. 



Limestone Series 

 (Zechstein). 



The total thickness of the Permian rocks is from 500 to 700 feet. 



Zechstein is a German term signifying ' Mine stone,' as it yields 

 copper-ore ; Kupfer Schiefer signifies copper-slate ; and Roth- 

 liegende (or Roth-todt-liegende), used by Werner, is a German 

 term signifying ' Red layers,' or ' Red dead layers,' as the copper 

 ceases or " dies off" before this bed is reached. 



' See also J. Gunn, G. Mag. 1SS4, p. 73. 



