84 Professor Favre on the Geology of the German Tyrol. 



and by a calcareous conglomerate, containing numerous nests 

 of a green matter resembling, as we have said, docomposed 

 pyroxene, and enclosing fragments of that mineral. These 

 sandstones and conglomerates are covered by the muschel- 

 kalk, M^hich is a more or less marly limestone.* We per- 

 ceive that the base of Kreutzkogl, near St Cassian, pre- 

 sents nearly the same section, and that this mountain, which 

 is dolomitie, rests on the musclielkalk. 



The superposition of the dolomites on the muschelkalk is 

 likewise seen in the north part of the base of Langkogl Jtnd 

 at the Col de Colfosco, where we find a greenish sandstone 

 partly formed out of the elements of the pyroxenic rocks. 

 This sandstone appears to be contemporaneous with the mus- 

 chelkalk, and contains small fossils which cannot be deter- 

 mined. (Astartes X) 



On ascending above the baths of Razes, we perceive on the 

 muschelkalk the pyroxenic tufas which form the surface of 

 the Seisser-Alp. This name is given to a great plateau 

 bounded by the Schlerns, the Palat-Spitz, the Blattkogl, the 

 Langkogl, and the Grodner-Tlial. It is clothed with pas- 

 turage and slightly inclined towards this valley. This py- 

 roxenic tufa, which is a kind of sand, more or less coarse, con- 

 taining numerous small crystals of pyroxene, is evidently de- 

 pendent on the pyroxenic porphyry seen at Pufl, St Christine, 

 &c. The tufa is perfectly stratified; it is formed by alternations 

 of substances, loose or of greater consistency, "VVe here ob- 

 serve rolled pebbles of all sizes, which have evidently been 

 tossed about by the waters, and are a submarine dejection. 

 What farther proves this are the numerous alternations of 

 this tufa with the limestones and dolomites which may be ob- 

 served in a remarkable escarpment situate near the chalets of 

 Molignon, not far from the pass which leads from the Seisser- 

 Alp to Campidello in the valley of Fassa. 



In this natural section which overlooks the chalets, we 



* The general view which I give here i.s sufficient for the end I propose, and 

 I refer for the details to the Cowp d'oeil sur la Geologie du Tyrol merhlional, by 

 JI. Emmerich, published in the Alpes de VAllemagne, by Schaubach, torn. iv. 

 1846. 



