Rev. A. Irving — On the Permian and Trias. 163 



takes tlie contrary view, and calls these rocks Permian, in order to 

 make the Edenside rocks harmonize with his system. More recent 

 and detailed examination of these rocks has led to the adoption of 

 Harkness's views on this matter, and to the rejection of Murchison's. 

 Mr. J. H. Goodchild, who has worked at the systematic survey of 

 these rocks, writes to me : " My own idea is that Sedgwick was right 

 in putting the St. Bee's sandstone and the shales that form its natural 

 base in the set of rocks which we have to call Trias. Phillips and 

 Harkness, and may be others, followed Sedgwick in putting the beds 

 above the Magnesian Limestone of the Eden Valley in with the 

 'Trias'; and it was only because Murchison thought there ought 

 to be an unconformity between the Permian and Trias, and he 

 could find no evidence of unconformity in our Edenside rocks, that 

 he took upon himself to put the upper half of them into the Permian." 

 Possessed by the notion that symmetry in classification was gained 

 by introducing the notion of a " Palceozoic Trias " as well as a Mesozoic 

 one, the facts exhibited in the rocks themselves were expected to 

 conform to theory ; if not, so much the worse for the facts. (How 

 different this from the almost excessive caution of our other great 

 master Lyell, now, like Murchison, numbered among the honourable 

 ones of the past whose work still lives !) The classification put for- 

 ward by Murchison still finds favour in some quarters ; and quite 

 recently so high an authority as Prof. Hull has proposed it for the 

 acceptance of the British Committee. We must therefore inquire 

 further, but briefly, how far such views have been confirmed by 

 recent observations in other areas than the Vale of Eden. 



(a) In the north-eastern area, Notts, Yorkshire, and Durham. 

 Here, as in the north-west, certain thick-bedded sandstones, with 

 included breccias, are found at the base of the Lower Mottled Sand- 

 stone of the Bunter. In deference to so high an authority as Sir R. 

 I. Murchison, I was myself, in common with some other observers, 

 misled as to these beds ; and in consequence argued, from what was 

 observed in Nottinghamshire, that there was something like a 

 gradation upwards of the Permian rocks into the Trias in that 

 district. In the new edition of Mr. Aveline's " Memoir on the 

 Geology of the Country around Nottingham," these particular rocks 

 are included with the Bunter series, and good reasons are given for 

 this being done. Mr. Aveline quotes the opinion of Mr. E. Wilson, 

 F.G.S., an accurate observer, on this point ; and to the papers by 

 this gentleman, • as well as to the memoir itself, the reader must be 

 referred for further information. It is pointed out by Mr. Aveline 

 that there is an unconformity in the north-eastern area between the 

 Permian and the Trias, but that this is not greater than that which 

 exists between the Middle Marls and the Lower Magnesian Lime- 

 stone, or between the Bunter and the Keuper. It seems, therefore, 

 that we may dismiss the notion of an " Upper Permian " series 

 existing in this area. 



(&) In South Lancashire, as has been recently shown by Mr. 



1 Vide Quart. Journ. Geol. Soc. yoI. xxxii. ; also Mr. Wilson's paper in the 

 Midland Naturalist, and letters to the Editor of the Geol. Mag. 



