Professor Favre on the Geology of the German Tyrol. 73 

 take into account the natural variations which I have spoken 

 of in treating of other she\h:'—(Bibltothegue Universelle de 

 Geneve, No. xxii., p. 123.) 



On the Geology of the German Tyrol and the origin of Dolo- 

 mite. By Professor Favre of Geneva. Communicated 

 by the Author.* 



Desirous of extending the field of my geological researches, 

 which for some time had been almost confined to the Alps 

 of Savoy, I eagerly availed myself of a proposal of Professor 

 Studer of Berne, to accompany him in an excursion to the 

 Alps of the Tyrol. I was fortunate in undertaking this jour- 

 ney along with this savant, who is as amiable as he is distin- 

 guished. The route he had marked out enabled us to ex- 

 amine the different formations which constitute the surface 

 of the Tyrol and Salzbourg. 



I have no intention of describing them all ; after a rapid 

 glance at the topography and ancient formations of this 

 country, I shall limit myself to a description of the pass 

 of Heiligen-Blut-Tauern, and some considerations on the 

 origin of dolomite. 



The Tyrol, whose mountains form the eastern prolonga- 

 tion of the Alps of Switzerland, presents some differences 

 from the latter, even in a picturesque point of view. The 

 large mountains are less elevated and less numerous. The 

 glaciers are not so large, they do not descend so far into the 

 valley, which indicates that the snow fields of the upper re- 

 gions are less extensive. 



The general character of the mountains of the Tyrol is 

 that they stand in a line following three great parallel chains, 

 runnmg very nearly from west to east. 



The chain of crystalline rocks is situate in the centre • 

 It IS placed between Innsbruck and Klausen, or rather it is 

 bounded by the upper part of the valley of Salza, and by that 

 of the valley of the Drave, so wild in its character. 



* Read to the Societo de Physique et .rili.toirc. Naturelle de Geneve, on 1st 

 Pobruarj' 1849. 



