SECTIONAL TRANSACTIONS.— C. 319 



The Middle Gondwana of India'' is unconformable to the Lower Gondwana with 

 the glacial deposits and may be taken as representing the Zechstein-Trias or Epiric 

 System. 



In India it seems probable that the Chideru Beds of the Salt Range may be the 

 base of the Epiric. 



As regards the Permian flora, according to E. Weass,^ if the division between 

 Palaeozoic and Mesozoic was made in the fossil plants it would be placed between the 

 Rothliegende and the Zechstein. 



Dr. C. T. Trechsiann. — The Permian Magnesian Limestone of North-East England 

 should be regarded as one formation along its whole extent from Cullercoats in North- 

 umberland to Nottingham. It is as distinct and self-contained as, for instance, the 

 Lias or the Chalk. 



One of the chief points of evidence for questioning the validity of the Permian in 

 England seems to be the apparent direct upward passage of the Middle Permian Red 

 Marls into Lower Mottled Sandstones of the Bunter along a stretch of country about 

 Bulwell and Kirkby-in-Ashfield, some ten miles north of Nottingham. I have for 

 several years held the opinion, following observations in Durham, that this upward 

 passage must be more apparent than real and that the red beds after the close of 

 Magnesian Limestone times transgressed widely over the exposed edges of the Permian 

 and came to rest successively upon Upper Magnesian Limestone, Middle Red Marls, 

 and Lower Magnesian Limestone. Only Lower Magnesian Limestone and Middle Red 

 Marls occur in the immediate vicinity of Nottingham ; the Upper Magnesian Lime- 

 stone does not appear till one reaches Collingthwaite, some 17 miles north and east of 

 Nottingham. The section in the Annesly — Kirkbj'-in-Ashfield railway cutting con- 

 tains a more or less concealed break or non-sequence, the lower part of the section of 

 red beds being verj' argillaceous ; and passes up quite suddenly into red sands of 

 Triassic aspect. 



In Durham the Magnesian Limestone is thickly developed and dolomitic, that is 

 to say, it consists of material derived from minerals dissolved in the waters of the sea. 

 The Middle Magnesian Limestone in Durham, comprising the Shell Limestone Brj-ozoa 

 Reef and its eastern and western bedded equivalents, is always found to the east of 

 the outcrop of the lower beds. The Upper Magnesian Limestone, comprising In 

 ascending order the Flexible Limestone, the Cannon Ball concretionary, and the 

 Hartlepool and Roker oolitic Dolomites ; rests in places upon the Reef, but chiefly to 

 the east of it or down its eastern slope, but has never been seen to the west. This and 

 other evidence, such as the gradual extinction of the fauna as one ascends in the Reef, 

 points to a sea shrinking eastwards, desiccating and throwing down its dissolved salts. 



That this eastward retrogression of the beds in Durham is not due to subsequent 

 denudation is shown by borings beneath the Tria^ south of the great concealed fault 

 that lies between Seaton Carew and Hartlepool. Here passing eastwards from the 

 Lower Magnesian Limestone outcrop at AyclifFe the hidden Permian increases in 

 thickness from 299 feet at Whitehouse Farm near Norton, to 878 feet at Seaton Carew, 

 some seven miles to the north-east. Borings on the Tees near Middlesbrough brought 

 up Dolomitic Oolites of the Hartlepool type full of gypsum. 



Along its stretch in Yorkshire the Upper Magnesian Limestone keeps well away to 

 the east of the outcrop of the lower beds. Rather north of Knaresborough the Middle 

 Red Marls disappear beneath Triassic red beds and are replaced in Durham by the 

 Middle Permian Bryozoa Reef. 



There seems no reason to do away with the Permian so far as north-eastern England 

 is concerned, as it is a formation quite distinct from the Carboniferous below and the 

 Trias above. The Permian fauna is a verj^ distinct one and has apparently only one 

 fossil, Splrlferlna cristata, common to the Carboniferous, and none to the Trias. The 

 Permian and Trias beds of England are continental in character and deposition must 

 have been Intermittent, and there must be many instances of non-sequence to cor- 

 respond with the Marine Permian and Trias of other regions. 



Prof. J. W. Gkegory, F.R.S. — The continuity of Geological Evolution is accom- 

 panied by the absence of definite boundaries to the Geological systems. Hence, their 

 validity has been repeatedly questioned. A crusade against the Permian System 



* Wadia, D. N.— Geology of India, 1910. 



■ Kavser, E. — Lehrbuch der Geologic. Sechate und siebente Auflage, I. Band, 

 1923, p."409. 



