76 MR. E. L. SHERLOCK ON THE RELATIONSHIP OF THE [Feb. I9I I, 



less clear. It is usually stated that there is an unconformable 

 overlap of the Permian by the Trias in this area ; but several 

 geologists, and notably the late Edward Wilson, thought that the 

 gap between Permian and Trias was much overestimated, and that 

 there might even be an actual passage between them. 



In this paper I attempt to prove the upward passage of the 

 Middle Permian Marls into Bunter in Nottinghamshire, then, using 

 the Middle Marl as a datum-line, to trace it northwards and to 

 note its relatious to the beds above and below and any lithological 

 changes of the strata. The result of this investigation is to show 

 that the 'Bunter' of Nottinghamshire is contemporaneous with the 

 upper part of the Permian of Yorkshire and Durham. 



During the years 1903-7 I have mapped, on the 6-inch scale, 

 the Permian outcrop (together with much of the Trias) from its 

 southern limit at Nottingham as far north as Market Warsop. 

 The area of the Permian outcrop is far too great to permit of the 

 examination of the whole in equal detail, but the entire length of 

 it has been traversed, and the chief sections, recorded by Aveline 

 and other geologists, have been examined. In addition, the 

 Permian has been seen at St. Bee's Head and at Penrith. 



The chief importance of the work in Nottinghamshire lies in its 

 application to the correlation of the New Red deposits in other 

 districts. A brief account is, therefore, given of the rest of the 

 Permo-Triassic outcrop as far as Northumberland, as well as the 

 supposed equivalent deposits of Cumberland and Manchester, and 

 new correlations with the Nottingham succession are attempted. 

 The palaeontology of the Upper Magnesian Limestone is examined, 

 and is shown to lend some support to the new views. 



The first considerable paper on the Permian of the north-eastern 

 district is that of Sedgwick, 1 on the geological relations of the 

 Magnesian Limestone, which describes the beds from Northumber- 

 land to Nottingham. Later, attention was directed chiefly to the 

 northern part of the outcrop ; but in 1861 J. W. Kirkby published an 

 important paper in this Journal. ' On the Permian Rocks of South 

 Yorkshire ; & on their Palaeontological Relations.' 



Geological Survey maps have been issued of the whole area, and 

 memoirs describing the southern half of the outcrop have been 

 published. Recently, two maps and memoirs embodying the results 

 of a re-survey of the neighbourhood of Nottingham have been 

 published. 



A paper by Edward Wilson, entitled ' The Permian Formation in 

 the North-East of England,' and dealing chiefly with the mode 

 of origin of the deposits, appeared in the ' Midland Naturalist ' 

 vol. iv (1881) pp. 97, 121, etc. 



In the year 1877 there were several letters in the ' Geological 

 Magazine ' on the relations of the Permian to the Trias near 

 Nottingham. Aveline, 2 who opened the discussion, referred to the 



1 Trans. Geol. Soc. ser. 2, vol. iii, pt. i (1829) pp. 37-124. 



2 Geol. Mag. dec. 2, vol. iv (1877) pp. 155-56. 



