THE PERMIAN PERIOD. 



199 



and shales, or of red or mottled marls, often gypsiferous, and 

 sometimes including beds of limestone. 



In North America, the Permian rocks appear to be confined 

 to the region west of the Mississippi, being especially well de- 

 veloped in Kansas. Their exact limits have not as yet been 

 made out, and their total thickness is not more than a few 

 hundred feet. They consist of sandstones, conglomerates, 

 limestones, marls, and beds of gypsum. 



The following diagrammatic section shows the general 

 sequence of the Permian deposits in the north of England, 

 where the series is extensively developed (fig. 133) : 



GENERALIZED SECTION OF THE PERMIAN ROCKS IN 

 THE NORTH OF ENGLAND. 



Fig. 133- 



oooo 



_,, 

 M j A 



r \ i 4- - ' . t -* T 



Upper Red Sand- 

 stones and Marls. 



: Magnesian Limestone. 



Marl Slate. 



Lower Red Sand- 

 stones and Breccias. 



Coal-measures. 



