402 Professor Sedgwick and Mr. Murciiison on the 



bays of Lower Styria — as no igneous rocks follow the direction of the valleys 

 or inclined planes, presented by the existing- surface of the country. On the 

 contrary, they rise in steep insulated masses — formed, evidently, before the 

 rivers drained through their present channels ; and they offer most emphatic 

 proofs of the enormous degradation and waste of the country, since the for- 

 mation of one of the newest regular deposits known in Geology. 



5. Basin of Vienna : Comparison of its Principal Deposits with those of 



Loiver Styria, ^c. 



We stated in the first chapter of this paper *, that the central axis of the 

 Alps, in its extreme eastern prolongation, formed the boundary between the 

 basins of Vienna and Styria — and that after partially disappearing under the 

 newer deposits (connected^ in point of fact, with both these basins) it again 

 emerged in the neighbourhood of Presburg. 



In applying the term basin, to the physical regions containing the tertiary 

 formations of Vienna and Styria, we use the customary language of Geology. 

 They were, however, nothing more than two deep bays in the ancient tertiary 

 sea, separated from each other by a great promontory connected with the cen- 

 tral ridge of the Eastern Alps f : and we find, as might under such circum- 

 stances be expected — that the deposits they contain, are in the same horizontal 

 or slightly inclined position, and that they exhibit very nearly the same suc- 

 cession of phenomena. It is indeed owing to their slight inclination that the 

 lowest tertiary groups in the neighl)ourhood of Vienna are almost unknown ; 

 having been reached only by deep borings for water (through the inferior blue 

 clay called Tegel), and by other artificial means. 



We subjoin the following synopsis of the successive deposits in the basin of 

 Vienna on the authority of M. Partsch, who has been long employed in work- 

 ing out the most minute details of their structure. Some of the facts were 

 verified by our own observations. The section (partly taken from the borings 

 above mentioned) is in the descending order : 



Average thick- 

 ness in feet. 



1. Alluvial loam called LosSy with terrestrial shells, of existing species (of the ge- 



nera Pupa, Helix, and Succinea), mixed with bones of Elephants of extinct 

 species. The average thickness of this deposit is about 60 feet, but at some 

 places the thickness is much greater 60 



2. Gravel and sand, with subordinate, concretionary, calcareous masses, sometimes 



oolitic. This group contains bones of the Mastodon, Anthracotherium, 

 Tapir, &c 70 



* p. 305. t Plate XXXV. 



