PROCEEDINGS 



OF 



THE GEOLOGICAL SOCIETY OF LONDON. 



1830. No. 17^ 



May 7.— Thomas England, Esq. B.A. of Pembroke College, Cam- 

 bridge; Howard Elphinstone, Esq. M.A. of Trinity College, Cam- 

 bridge ; and Robert Edmond Grant, M.D. F.R.S. Ed. Professor of 

 Comparative Anatomy and Zoology in the University of London, — 

 were elected Fellows of this Society. 



A Paper was read, entitled " Sketches explanatory of Geological 

 Maps of the Archduchy of Austria and of the South of Bavaria:" by 

 Ami Boue, M.D. For. Mem. G.S. &c. 



The accompanying maps of the Archduchy of Austria and of Ba- 

 varia were made during repeated visits to those countries, and partly 

 with the assistance of M. Partsch of Vienna. 



The author premises that in consequence of his last visit, in 1829, 

 he has changed some classifications, and rectified certain errors which 

 appear in his former works. 



I. Structure of the Archduchy of Austria. — Dr. Bou^ describes the 

 principal part of Austria as consisting of the primary chain of South- 

 ern Bohemia on the north, and of the great secondary calcareous 

 Alpine chain on the south, which are separated from each other by 

 the tertiary and alluvial valley of the Danube. He divides this last 

 region into three parts : — 



1 . The molasse and alluvial basin of Upper Austria, extending from 

 Bavaria to near Blindenmarkt and St. Leonhard. 



2. The basin of St. Polten, containing shelly sand, sandstone, marl, 

 alluvial marl, and gravel. 



3. The basin of Vienna, which is now united with that of St. Polten 

 by a narrow gorge of the Danube. 



The direction of the primary chain of Bohemia is from south-west 

 to north-eastj gneiss being the predominant rock, with some sub- 

 ordinate masses of granular limestone and diorite. Granite occurs in 

 the western, and sienite, leptinite, and serpentine in the eastern part 

 of this range. The central ridges of the Alps are primary, and these 

 are succeeded, in an ascending order, by talco-quartzose rocks, distin- 

 guished by masses of compact limestone with iron ore. Between the 

 preceding rocks and the escarpments of the Alpine limestone, are an- 

 cient longitudinal valleys, which certain rivers occupy in their early 

 course, and afterwards quitting abruptly, run at right angles 

 through newer and transverse rents in the secondary formations. At 

 the base of the Alpine limestone, and subordinate to it, are red sand- 

 stone and shale, with gypsum, but without porphyry. This group 

 can be traced from Mont Blanc to Hungary, and it again appears- 



