Yol. 67.] PERMIAN TO THE TRIAS IN NOTTINGHAMSHIRE. 113 



A small unconformity, between the Magnesian Limestone and 

 the Marl above it, is recorded by Goodchild as occurring at St. Bees 

 Head. The succession there is so similar to that of South 

 Nottinghamshire (showing in both alike the order : — limestone ; 

 small unconformity ; followed by Marl passing upwards through 

 beds resembling Waterstones into Bunter) that one is tempted to 

 correlate the two, although they were formed in distinct basins. 



In the Manchester district the Upper Magnesian Limestone is 

 shown, by the fossils, 1 to be represented by red clays with only 

 subordinate bands of limestone, and here also there is not known 

 to be any break between these beds and the Trias above, whieh is 

 said to be of Bunter type.' 2 



Dr. H. T. Brown has described 3 an unconformable junction of the 

 Trias and Permian at Swadlincote (Leicestershire), where there is 

 5 to 8 feet of Bunter conglomerate and sandstone resting uncon- 

 formably upon 27 feet of Permian sandstone, clay, and breccia, and 

 covered by Lower Keuper. It is evident that these thin beds 

 cannot represent, chronologically, much of the thick Bunter and 

 Permian deposits of other districts. The unconformity observed 

 at Swadlincote may, therefore, be supposed to represent some part 

 of the strata seen in the Nottingham area : if, indeed, the ' Bunter ' 

 is not really the basement- bed of the Keuper, such as may be seen 

 at Nottingham. 



Correlations of beds in distinct areas are, however, not very 

 certain, as was pointed out by Green. 4 He remarked that 

 deposits such as those of the Permian, formed in so many distinct 

 basins and under changing conditions, must necessarily be totally 

 different in different areas. He objected to the habit of desig- 

 nating subdivisions of the English New lied by German names. 

 For example, there was no proof that the New Bed Sandstone was 

 the time-equivalent of the Bunter. 



The question of the independence of the Permian and Triassic 

 Systems is a wide one, and can only be settled by a consideration 

 of the strata in other regions of the earth, as well as in Britain. 

 The evidence from Nottinghamshire, however, is of importance, 

 because the Nottingham district has been relied on for proof of a 

 break between Permian and Trias, which, elsewhere in this country, 

 has failed to bear investigation. Thus Mr. H. B. Woodward, 

 while supporting the indivisible character of the Permo-Trias, 

 points to Nottinghamshire as a difficulty, and writes : — 



' Near Nottingham there is evidence of the overlap of Permian rocks by the 

 Trias, which crosses some of its upper divisions, and finally rests on the Coal- 

 Measures. Even here there is no positive evidence of denudation between the 

 Permian and Bunter formations, inasmuch as the overlap by the Bunter Sand- 

 stone may have coincided with a depression of the area that took place after 

 the Upper Permian Beds were deposited.' (1887, p. 209.) 



1 H. B. Geinitz, 1890, p. 539. 2 See J. W. Gray & P. P. Kendall, 1894. 



3 ' The Permian Rocks of the Leicestershire Coal-Field ' Q. J. G. S. vol. xlv 

 (1889) pp. 1-40. 4 A. H. Green, 1887, p. 290. 



Q. J. G. S. No. 265. i 



