Vol. 67.] THE PERMIAN AND TRIAS OP NOTTINGHAMSHIRE. 81 



confused with the Bunter above. At Nottingham the limestone 

 is perhaps 20 feet thick ; it increases, however, in thickness north- 

 wards, at first slowly, but at Sutton-in-Ashfield rapidly, and then 

 becomes more varied in its characters. It contains a considerable 

 amount of insoluble sandy residue, especially near its southern 

 margin. Fossils are very rare, and consist of casts of lamellibranchs. 



The ' Marl Slate ' is of local occurrence only. Near Nottingham 

 it is a dolomitic flagstone, which passes upwards into the Magnesian 

 Limestone. Fragments of plants are found in it, together with an 

 occasional Schizodus or Myalina. 



The Breccia, which is even more local than the Marl Slate, is 

 well developed at the southern termination of the Permian outcrop, 

 marking the bouudary of the Permian sea. 



A little farther north, at the latitude of Kirkby-in-Ashfield, the 

 Marl Slate seems to be represented by grey clays, with occasional 

 thin bands of nearly pure limestone. These latter are interesting 

 on account of the fossils, chiefly lamellibranchs and foraminifera, 

 which they contain. The grey clay, when weathered, closely re- 

 sembles the soils over the Coal-Measure shales, and, in the absence 

 of the breccia, the Permo-Carboniferous boundary becomes very 

 difficult to trace. 



The best sections of the Permian in South Nottinghamshire are 

 along the Great Northern Railway (Derby & Nottingham Branch), 

 and in the cuttings on the Great Central and Midland Railways, 

 near Annesley. The former of these railway-sections was fully 

 described by E. Wilson in 1876, but the Great Central sections 

 have not been hitherto described, except very briefly by myself. 1 



(a) Sections on the Great Central and Midland 

 Railways, near Annesley. 



Two railways tunnel through the Robin Hood's Hills, 9| miles 

 north of Nottingham Market Place. One of these, the Great Central 

 main line, approaches the Mansfield Branch of the Midland Railway 

 obliquely, and finally passes under the latter line. The cuttings 

 at the extremities of the two tunnels together show a complete 

 succession, from almost the base of the Magnesian Limestone to 

 the top of the Lower Mottled Sandstone. 



Following first the Great Central Railway northwards (see fig. 2, 

 p. 80), the line begins to cut gradually into the plain of nearly hori- 

 zontal Lower Mottled Sandstone. As successively lower beds are 

 reached the character of the strata is seen to change gradually, the 

 red sandrock becoming very fine-grained with a considerable increase 

 in the proportion of clay, and at the same time developing clay- 

 partings, which give it a flaggy structure. At the entrance to the 

 tunnel, the beds at the bottom of the cutting, now about 50 feet 

 deep, are so fine-grained and marly that it becomes difficult to 

 decide whether they should be regarded as a sandy marl or as a marly 



1 W. Gibson & others, 1908, p. 129. 

 Q. J. G. S. No. 265. e 



