382 Professor Sedgwick and Mr. Murchison on the 



Chap. V. 



On the Tertiary Formations of Lower St^ria, ^c. 



INTRODUCTION. 



We here quit the newer deposits on the north flank of the Eastern Alps, 

 and proceed at once to the tertiary formations of Lower Styria. They 

 occupy a region of extraordinary beauty, and are not only of great thickness, 

 but are well exposed in many fine natural sections : and they derive an addi- 

 tional interest from their being the extreme western prolongation of vast 

 groups of strata which form all the lower elevations between the Drave and 

 the Danube, and stretch into the heart of Hungary. As these widely ex- 

 tended groups are continuous, they must have had a common origin ; and 

 whatever we can prove respecting one portion of them^ ^^y, with proper 

 limitations, be safely predicated of all the others. By help of the clear suc- 

 cession of deposits in Lower Styria we may explain some of the phenomena 

 in the great plains beyond the termination of the Eastern Alps ; and in this 

 way we shall endeavour to account for the position and relations of the suc- 

 cessive newer groups in the basin of Vienna. 



The conglomerate, sandstones, and marls, entering into the composition of 

 the groups we are about to describe, appear to have been formed in a bay of 

 an inland sea; which once filled the basin of Hungary, and extended to the 

 base of the mountains forming the extreme eastern termination of the chain 

 of the Alps. For all these groups are of marine origin, and are nearly hori- 

 zontal ; and at their western extremity, among the older and more elevated 

 formations, they fill an irregular, trough-shaped depression, through which the 

 waters of the Mur, the Raab, and the Drave, make their way to the Lower 

 Danube. From this region they are gradually expanded into the plains on 

 the confines of Hungary*. 



The tertiary formations of Styria are bounded, towards the east, by the 

 frontier line of Hungary, and towards the south by the calcareous chain of 

 the Matzel Gebirge, and the great alluvial plain of the Drave. On the 

 south-western side the boundary line is irregular and ill defined. At Mar- 

 burg it comes up to the ridges connected with the Bacher Gebirge ; and, 

 after ascending the Drave for some way, leaves the ridge of the Radlberg 

 t«) the west, and descends towards Eibeswald. From this place the western 

 boundary ranges at the base of the woody ridges which descend from 



* See the accompanying map, Plate XXXV. 



