222 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Nov. 4, 



the breccias and conglomerates which form the grand mass of the 

 Permian rocks in that region. The mineral characters bear out 

 the analogy. They are described as " argillaceous and thick-bedded 

 sandstones, of a dark-red brick-colour," a description which might 

 be properly applied to what are here considered their representatives 

 in England. 



Hence we may infer, that before the introduction of those littoral 

 conditions of land and sea, accompanied by the outburst of volcanic 

 forces, which resulted in the production of the trappoid breccias of 

 Germany, and, as maintained by Professor Ramsay, accompanied by 

 glacial agencies in Britain, there appears to have been an introductory 

 stage, in which deeper seas and more tranquil modes of deposition 

 prevailed. 



In Worcestershire these basement-beds of purple sandstones and 

 marls attain a thickness of 400 feet. They repose unconformably on 

 the coal-measures near Bridgnorth, Enville, and Hales Owen, and 

 are succeeded by the zone of the trappoid breccias and calcareous 

 conglomerates, so prominently exhibited in the Clent, Lickey, and 

 Enville Hills*. 



So far, the analogy in the order of succession of the Permian beds 

 in both countries holds good. 



Zechstein. — This formation is very sparingly represented at Hei- 

 delberg, and is generally altogether absent. It consists of a band of 

 yellow magnesian limestone, with imperfect fossils. As the mag- 

 nesian limestone of the North of England is universally admitted to 

 be the representative of the Zechstein, it will be unnecessary to dwell 

 longer upon it here. 



Trias. 



Bunter Sandstein. — The sandstone of the Odenwald has given 

 rise to considerable controversy regarding its age, doubts having 

 been entertained whether it might not be referable to the " Lower 

 Bunter," or "Bunter Schiefer," of the German Geologists, a forma- 

 tion which Sir R. Murchison has truly shown to be of Permian age. 



An examination of this sandstone from its base at Heidelberg for 

 miles along the valley of the Neckar, up to the point where it is overlaid 

 by the Muschelkalk, leads me to the conclusion that the whole weight 

 of evidence is in favour of its Triassic age ; and in this opinion I am 

 borne out by the authority of Dr. von Leonhard, who has mapped and 

 described it as such in his memoir on the Geology of Baden j. 



At the Kaiserstuhl, which rises behind the town and castle of 

 Heidelberg to a height of about 1300 feet above the Neckar, and 

 1723 feet above the sea, the sandstone attains a thickness of 1400 

 or 1500 feet. Throughout the Odenwald it is but very slightly 

 inclined from the horizon, and gradually descends towards the boun- 

 dary of the Muschelkalk at an inclination of 4 or 5 degrees. 



* See Maps of the Geological Survey of Great Britain, Nos. 61, S.E., and 

 54, N.W. 



f The Sandstone of Heidelberg is also marked as Trias in von Becker's 

 " Geognostische Uebersichtskarte von dem Grossherzogthum Hessen," and in 

 SirR. I. Murchison and Prof. Nicol's Geological Map of Europe, 1856. 



