INTRODUCTION. 



xvii 



Our attention may, in the next place, be directed to the Permian rocks on the 

 Continent of Europe. In Thuringia, these rocks hold exactly the same relative 

 position as they do in the North of England : wherever the Carboniferous, or Triassic 

 rocks are associated with the Permian deposits, these are seen overlying the former, 

 and underlying the latter : the agreement is still further borne out in a more detailed 

 point of view, as shown by the following comparative table of the constituent members 

 of both the English and Thuringian Permians. 



Members of the Thuringian Permians. 



Stinkstein. 



Kauchwacke.^ 



Dolomit.2 



Zechstein. 



Mergerl-scbiefer.* 



Todte-liegende.* 



Members of the North of England Permians. 



Crystalline, and Non-crystalline Limestone. 

 Brecciated, and Pseudo-brecciated ditto. 

 Fossiliferous ditto. 

 Compact ditto. 

 Marl Slate. 

 Inferior Sandstone. 



The upper members of the Thuringian Permian rocks appear to assume the 

 character of the English Midland Permians ; and, like the latter, they often become 

 obscurely blended with the overlying strata of the Triassic system. In other parts of 

 Germany, as Saxony and Silesia, some, or all, of the same members are found ; and 

 they are met with still further to the east, particularly on the confines of European 

 Russia, where they become somewhat modified- Count Keyserling having discovered 

 true Permian rocks in Petschora-land, bordering the icy sea, it is extremely probable, 

 as surmised by De Koninck, from an examination of their fossils, that M. Robert met 

 with the same deposits in the still higher region of Spitzbergen. 



The localities noticed afford indisputable evidence, that the Permian Ocean 

 occupied an immense area, extending from Ireland to the Ural mountains, and 

 probably to Spitzbergen, with its northern boundary line defined by the Carboniferous, 

 Devonian, Silurian, and Igneous regions of Scotland, Scandinavia, and Northern 



1 I saw none of the beds of Rauchwacke and Stinkstein myself when in Thuringia ; but from the 

 description which Freiesleben gives of thern, as abridged by M. d'Aubuisson de Voisins, (vide 'Traits de 

 Geognosie,' tome i,) I have little or no doubt of their being the exact equivalents of the English brecciated, 

 and pseudo-brecciated limestones, and of the crystalline (coralloidal, globulo-concretionary), earthy, compact, 

 and oolitic limestones abounding in the county of Durham. 



2 This member has been variously named by German geologists. It is often called Upper Zechstein, 

 Zechstein-dolomit. The bed which I saw of it at Schlossberge von Konitz, agrees most remarkably in 

 colour, niineral and chemical characters, structure, and organic contents, with the one occurring at Hum- 

 bleton and TunstaU Hills. Near Konitz, it reposes on beds (Zechstein), agreeing with the compact grey 

 limestone at Thickley, Ferry-Hill, and other places. 



3 The principal difference between the Mergerl-schiefer and our Marl Slate is, that the former abounds in 

 some places with argentiferous and other copper ores, in which case it is called Kupfer-schiefer. 



* The Todte-hegende varies, like its English equivalent, in colours ; when light coloured, it is called 

 Weissliegende ; when red, rothe-todte-liegende. 



2 



