Structure of the Austrian Alps, 4' c - 85 



To explain more fully the structure of this part of the Alps, 

 we have added another parallel section (fig. 2), about thirty 

 miles west of the former, from the primary rocks at Gastein 

 across the transition formations of the Upper Salza, the 

 red sandstone series of Werfen, the older Alpine limestone of 

 the Tannen Gebirge, the saliferous deposits of Hallein, the 

 younger Alpine and hippurite-limestone of Untersberg, to the 

 tertiary plains of Bavaria. 



After these introductory remarks, we may proceed to notice 

 each of the successive deposits seen on the line of transverse 

 section, and on other corresponding parallels of the eastern 

 Alps. They may be subdivided into the following natural 

 groups in the ascending order. 1. Primary crystalline rocks 

 forming the central axis. 2. Crystalline rocks with calcareous 

 beds containing a few traces of organic remains ; the system 

 graduating into rocks agreeing with the ordinary transition 

 type. 3. Red marl, sandstone, and gypsum, &c. ; containing 

 in parts of their range large, subordinate masses of magnesian 

 limestone. 4. Older Alpine limestone. 5. Alpine limestone 

 with subordinate saliferous deposits. 6. Younger Alpine lime- 

 stone. 7- Tertiary formations. 



§ II. Successive Formations of the Eastern Alps. 

 1. Central Axis of primary Rocks. 



The primary rocks of the central axis have their culmina- 

 ting peaks on the eastern borders of the Tyrol, where the 

 Grosse Glockner and the Venediger Alp rise to the respec- 

 tive elevations of 11,775 and 11,698 Vienna feet* above the 

 level of the sea. To the east of these peaks the central ridges 

 diminish gradually in elevation; separating, in their range, 

 Carinthia on the south from the Salzburg country on the 

 north. Following the direction of the Mur for a considerable 

 distance, they are finally divided into two irregular branches; 

 one of which is prolonged in a south-easterly direction into the 

 Bacher Gebirge, and forms the south-western boundary of 

 the tertiary basin of Gratz; the other is continued in the di- 

 rection of the principal axis of the Alps, and forms the great 

 boundary between the tertiary basins of Vienna and Styria. 

 This latter branch, after disappearing under some of the re- 

 cent deposits connected with the Vienna basin, emerges near 

 Presburg, and is said finally to die away in the low ridges 

 extending thence towards the north-eastf. 



It 



* 12,281 and 12,201 English feet. 



f The gradual diminution in the elevation of the central axis, as it ranges 



from 



