84 Prof. Sedgwick and Mr. Murchison on the 



of the several formations will be referred *. This section com- 

 mences in the marshes on the shores of the Adriatic, passes 

 through the plains of Udina to the foot of the Alps, inter- 

 secting the tertiary marls and conglomerates on the left bank 

 of the Tagliamento : then traverses the calcareous chain (con- 

 nected with the Julian Alps) to the longitudinal valley between 

 Tarvis and Ponteba, in a part of which is the outcrop of the 

 sandstone, red marl, and conglomerate inferior to the Alpine 

 limestone. It then crosses a low longitudinal ridge of doubt- 

 ful character, but based upon, and partly composed of transi- 

 tion rocks, and is continued through the secondary, dolomi- 

 tic ridges of Bleiberg to the valley of the Drave, which here, 

 like so many of the longitudinal valleys of the Alps, forms the 

 boundary between the primary and secondary ridges of the 

 chain. It will be seen by the general section, that the Blei- 

 berg dolomites rest on red sandstone and red gypseous marls ; 

 and that the secondary system is based on grauwacke, which 

 contains beds of limestone with fossils resembling those of 

 transition limestone. From the Drave the section is continued 

 through the primary region of the Alps, over the Katsberg, to 

 the valley of the Mur at St. Michael. These primary ridges 

 are chiefly composed of micaceous schists, the beds generally 

 ranging parallel to the principal chain, and dipping nearly due 

 south. From the valley of the Mur the section is prolonged over 

 the crests of the Tauern Alp to the longitudinal valley of the 

 Enns at Radstadt. This part of the line cuts through a great 

 succession of mineral masses, some of which, though eminently 

 crystalline and primary in external character, contain a few 

 subordinate beds of limestone with organic remains. The dip 

 of these transition beds is irregular ; but on the northern flank 

 of the Tauern Alp, and in the ridges near Radstadt, the strata 

 become less crystalline, and the prevailing dip is unequivocally 

 towards the north. From Radstadt the section crosses some 

 of the newer transition rocks graduating insensibly into the 

 conglomerates, red sandstone, and gypseous marls; which 

 here, as on the Italian side, form the base of the whole Al- 

 pine limestone system. The line is then continued through 

 the great precipices of the older Alpine limestone; through 

 the middle system with the subordinate saliferous marls ; and 

 through the younger Alpine limestone, flanked by the sand- 

 stones, marls, and conglomerates of the tertiary formations. 



The principal section is drawn in such a direction as to 

 show the position of the unconformable beds of Gosau, and 

 the commencement of the tertiary system at the foot of the 

 Traunslein. 



* See Plate II. fig. 1. 



To 



