SECTIONAL TRANSACTIONS.— C. 323 



Does the unconformity at the base of the Bunter in the Midlands, or at the base 

 of the Hopwas Breccia where that occurs, represent the time-equivalent of the whole 

 of these vast processes of mountain-building, erosion and deposition, and the whole 

 of the Permian as it occurs in the rest of Britain and abroad ? It would seem so if 

 we are to believe those who roundly assert that tlie whole of the Enville Beds are 

 Carboniferous, and the Hopwas (Nechells) Breccia is Trias, and that no Permian 

 rocks are present in the Midlands. 



I have sho^vn elsewhere that there exists under a large area in Birmingham a 

 mass of coarse breccia and sandstone (Nechells Breccia), proved to be upwards of 

 400 feet thick in places, known to rest at Nechells discordantly on the Calcareous 

 Conglomerate and immediately overlain in different places by the Keuper Sandstone, 

 Upper Bunter Sandstone or Bunter Pebble Beds. It has affinities with the Hopwas 

 Breccia and is probably part of the same group. Some of these Nechells Breccias, 

 especially in their lower portions, are indistinguishable from the Warley Breccias 

 which lie to the west of Birmingham and which are classed by the Surve}"^ and 

 Wickham King with the Clent Breccia. Again, typical Bunter Pebble Beds at 

 Hocklc}' in West Birmingham rest upon Warley Breccia at a depth of 610 feet, while 

 only a mile to the east the Bunter is resting upon the Nechells Breccias, which 

 contains material of the Warley type. Further evidence bearing on this is now in my 

 possession and will be shortly published. 



It will thus be seen that if the present Survey reading of the general succession, 

 which is admittedly tentative, were to be taken as final, it would mean that we should 

 have a great breccia-sandstone-marl group, passing up from the Carboniferous to 

 the Trias, with no considerable break so far determined. We should have in fact a 

 state of things not unlike that in West Cumberland and the Vale of Eden, described 

 bj' Dr. Bernard Smith, where there appears to be a tran?ition breccia series linking up 

 the Permian with the Triassic deposits. But in the case of the Birmingham district, 

 the linking up is between the Carboniferous and Trias, with no room for a Permian 

 System. On the other hand, if a satisfactory dividing line can eventually be fixed 

 between the Nechells or Hopwas Breccia and the Warley or Clent Breccia to the west, 

 then the break between the Palaeozoic and Mesozoic eras would occur in the immediate 

 neighbourhood of Birmingham within the limits of a great Breccia group. 



In other words we should have very similar breccia groups, indicative of similar 

 physiographic conditions, and containing materials derived from much the same 

 source, both below and above the unconformable junction. 



Without going f lu-ther into details, enough has been said to show that the Permian 

 problem of the Midlands has not yet been cleared up, and except for the convenience 

 of map display the grouping of the Enville Beds with the Carboniferous does not 

 carry us very far, and in any case should be regarded as tentative and open to revision 

 whenever new facts emerge. 



In my opinion, the wise and safe course to pursue is to keep the Permian Sj'stem 

 in being, at any rate until there is a demand among the Permian specialists of the 

 world for its suppression. In the meantime let us be frank and admit that there are 

 certain deposits in this country bridging the Carboniferous and the Trias which at 

 present are incapable of exact classification, neither provably Carboniferous nor 

 provably Trias. To detach them and link them up with either is apt to produce, 

 after a while, self-deception and a false sense of security. There would always be the 

 probability that they are the time-equivalent of Permian rocks elsewhere. Patient 

 research in the future will reduce the number of doubtful and unknown elements in 

 the problem. 



Dr. H. C. Vebsey. — It is suggested that the difficulties in fixing limits to the 

 Permian System and in correct correlation between marine and continental develop- 

 ments can be overcome by adopting a new basis of correlation and re-defining the 

 system accordingly. The various episodes or phases of the Hercynian revolution 

 are all of sufficiently ^^■idespread character to afford reliable criteria for correlation, 

 accompanied, as they are, by important faunal and floral changes. The Sudetian 

 and Asturian phases are both used as limits to major divisions in the Carboniferous. 

 The generally accepted beginning of the Permian period, i.e. at the Autunian, is not 

 accompanied by any earth movement while the Autunian is so closely allied, litho- 

 logically and florally, to the Stephanian that it seems desirable to group them together 

 as the highest major division of the Carboniferous. After the Autunian ( = Lower 

 Rothliegende) the Saalian episode is shown by extensive unconformities and floral 



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