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



the great Permian breccias of the West of England, and of Thiiringen. 

 It forms here simply the basement-bed of the Magnesian Limestone 

 and Marl Slate Series. There is a marked unconformity between it 

 and the Coal-measures. 



3. Mr. Wilson, who has for some years given great attention to 

 the north-eastern area, has furnished good reasons, both in the papers 

 just referred to, and in a further contribution to the Midland Na- 

 turalist (vol. iv.), for believing that in this area the " Rothliegende " 

 is non-existent, and that the true base of the Permian series in the 

 north-east of England is the Marl-slate with its underlying breccia. 

 The so-called " Lower Red Sandstone," including the " Rotherham " 

 and " Pontefract " Rocks, are regarded as true upper Coal-measures, 

 as they have been for years past by the mining engineers of the 

 district. Sanction to this view is given in the new edition of the 

 Survey Map. It appears, therefore, that in our north-eastern area 

 the Dyas of Germany is represented by one, and that its uppermost, 

 formation only ; the Magnesian Limestone with its subordinated 

 Marls and thin-bedded Sandstones representing the Zechstein, while 

 the Marl Slate series may be taken as the equivalents of the Kup- 

 ferschiefer, which over a large part of Germany forms, as is well 

 known, the base of the Zechstein formation. 



If now we turn our attention to the Carlisle Basin, we find things 

 reversed or nearly so. Years ago the rocks of this area were well 

 described by Prof. Harkness.^ He described six different sections, 

 in four of which the rocks classed as Permian in the paper referred 

 to are shown to rest on Carboniferous strata ; in the other two 

 sections they rest immediately upon rocks of Silurian age. Intrusive 

 igneous rocks break in upon these deposits, as before mentioned, and 

 as they do upon the Rothliegende in Germany. There is no distinct 

 Dyassic division of the series here, though it is in the upper portion 

 that the dolomitic beds occur ; but even these are quite subordinated 

 to the sandstones and shales with which they are interstratified. 

 The fossil evidence is not very powerful, and is derived mostly from 

 plant-remains ; but these, as determined by Mr. Etheridge and Prof. 

 Heer, give a Dyassic aspect to the group. Petrographically the series 

 reminds one of the Lower formation of the Dyas, as it occurs in 

 Bohemia on the south side of the Riesengebirge, in which feeble 

 limestone deposits occur. In both cases the calcareous deposits are 

 suboi'dinated to those sedimentary deposits which are referable in 

 their origin to mechanical agencies. It is in their petrographical 

 character that these members of the same great system found in 

 these widely distant areas would seem to bear the closest resemblance 

 to one another. The enormous development of the breccias and 

 sandstones of the Eden Valley and the vicinity reminds us of the 

 gigantic proportions which similar deposits attain in Thiiringerwald. 

 In Annandale and some parts of Dumfriesshire and in the Eden 

 Yalley the breccias form the base of the series ; but in the Valley of 

 the Nith, on the west of Penrith, and in the section from " Great 

 Ormside to Roman Fell," the base is made up of massively-bedded 

 1 Vide Q.J.G.S. vol. xviii. 



