Vol. 67.] THE PERMIAN ANJ) TEIAS OF NOTTINGHAMSHIRE. 79 



II. Stratigraphy 

 (1) South Nottinghamshire. 

 In this area the succession is as follows : — 



Rhsetic (fg) Rustic. 



Keuper Marl (fe) 1 



,. ^ \ Keuper. 



Waterstones (1°) J 



Pebble Beds (&) •> 



\ BUNTER. 



Lower Mottled Sandstone (f *) J 



Permian ( Middle) Marl (e 3 ) v 



Magnesian Limestone (e 2 ) | 



,,,,„,,,,,, V Permian. 



' Marl Slate ' (e 1 ) f 



Breccia ) 



[The symbols in parentheses are those used on the Geological Survey maps.] 



The upper divisions of the Trias may be dismissed in a few 

 words. The Rhsetic, the lowest beds of which are best seen at 

 Beaconhill (Newark), is sharply marked off from the Tea-green 

 Marls, which, as usual, form the highest beds of the Keuper. On 

 the other hand, the black shales seem to pass upwards, by the 

 incoming of limestone bands, into the Lias (well seen along the Great 

 Central Railway, south of East Leake Station). 



The Keuper Marl presents its usual character of a red silty clay 

 with thin sandstone bands, which increase in thickness and number 

 until sandstone predominates, and the Waterstones come in. 



Between the Waterstones and the Bunter Pebble Beds there is 

 probably a slight unconformity. This is indicated by some 

 discordance in strike, by a marked lithological change, and by the 

 presence, at certain places, of a few inches of conglomerate at the 

 base of the Waterstones. The absence of the Upper Mottled Sand- 

 stone (f 3 ) above the Pebble Beds cannot be regarded as evidence of 

 an unconformity, owing to the local character of the Bunter sub- 

 divisions. The thickness of the Keuper Marl may be taken as from 

 600 to 700 feet, and that of the Waterstones as from 80 to 200 feet. 



The two divisions of the Bunter differ markedly one from the 

 other, although there is a passage of the lower into the upper (except 

 at Mansfield). The Lower Mottled Sandstone is a fine-grained, rather 

 marly sandrock, of a deep red colour, with sometimes large yellow 

 patches. Rounded pebbles of the usual Bunter type are quite 

 absent, except in the passage-bed at the top, but it contains 

 thin gritty bands, which, at times, are sufficiently coarse to be 

 termed ' breccias.' False bedding occurs, but is much less common 

 than in the Pebble Beds above. The Pebble Beds are considerably 

 false-bedded, with rounded pebbles, either scattered sporadically, or 

 grouped into strings or thin conglomeratic bands, and the sand is 



