1850.] ZIGNO ON THE VENETIAN ALPS. 423 



The district which I am about to describe is bounded on the east 

 by the Taghamente, on the north by Carinthia and the Tyrol, on the 

 west by the Adige, and on the south by the plain which extends to 

 the Po. 



The Tagliamente, after running from west to east along the valley 

 called the * Canal di Sochieve/ which is parallel to the main chain of 

 the Alps, receiving the torrents which run from north to south (such 

 as the Lumici, the Degau, the Bret, and the Fella), turns sharply to 

 the south and enters the plain between S. Daniele and Spilimbergo, 

 after having intersected Jurassic, cretaceous, and tertiary formations ; 

 whilst the torrents I have mentioned cut through still older strata, 

 which I make no question are triassic. The celebrated Von Buch in 

 1 824 pointed out that the Tagliamente from its source to its junction 

 with the Fella formed the limit between the limestone mountains to 

 the south and the formations to the north, which he then called 

 grauwacke. It is easy to verify the truth of this observation of M. 

 von Buch's, for as the valley called the Canal di Sochieve runs par- 

 allel to the principal chain, the calcareous beds are seen to dip from 

 north-west to south-east, whilst the older rocks are exposed in the 

 transverse valleys which conduct the torrents from the main chain to 

 the left bank of the Tagliamente. In these valleys, micaceous grits, 

 argillaceous schists, and a thick formation of sandstones, accompanied 

 by gypsum and by magnesian and bituminous limestones, indicate 

 the presence of older rocks. Beds of coal have also been found here, 

 and it appears certain that the coal is intercalated between the mag- 

 nesian limestones. Prof. Meneghini, the distinguished botanist, has 

 not satisfied himself whether this formation belongs to the trias or to 

 the zechstein ; but from the fossils which I have found in it, I am of 

 opinion that it is triassic. These consist of Aviculce, among which is 

 the A. socialis, Schlot. sp., mth Terebratula vulgaris, Schlot. sp., and 

 other shells, not determinable, but with triassic characters. The thick 

 beds of limestone which underlie the grits do not contain these fossils, 

 which makes me suspect that these latter may be older than the 

 muschelkalk. This question I propose to discuss in a work devoted 

 to the geology of Friuli, which is stiil a virgin soil. Be this as it 

 may, the grits which cover the limestones are certainly of triassic age. 

 In Dechen's Map, published in 1839, a considerable formation of mi- 

 caceous schist is marked to the north of the Tagliamente, between the 

 sources of the Piave and the Degau, and to the east of the latter torrent 

 a disconnected mass of argillaceous schist is represented as extending 

 between the Jurassic rocks of Friuli and the Poecilian formation of the 

 Carniola Alps. I have no doubt that when I shall have extended my 

 researches to that quarter, I shall find the older rocks of the chain ; 

 but on the side of Paluzzo, Rigolato, Sapada, to the very sources of 

 the Piave, the higher mountains consist solely of thick beds of the Ju- 

 rassic age. This rock forms all the heights bordering the valleys 

 through which flow the torrents Argino, Meduna, and Zelline, as well 

 as the summits of the high mountains of Friuli, whose bases, as we 

 have seen, to the north are triassic. To the south, and in certain 

 basins, the higher country is composed of neocomian and cretaceous 



