24 GEOLOGICAL MEMOIRS. 



the district ; they are of marine origin, and contain traces of fossil 

 Plants. The anthracite-deposits thin off towards the Alps of Savoy 

 and Dauphiny. 



The Trias is well developed on both sides of the chain, as at 

 Hallstatt on the north and St. Cassian on the south. M. Mortillet 

 gives for this, as for each formation, lists of the fossils from various 

 localities, and institutes a comparison of them. During this epoch 

 the land continued raised above the sea, but volcanic eruptions 

 occurred on a large scale. 



Lower Lias has been shown to exist in Lombardy on one side and 

 in Dauphiny on the other. The Middle and Upper Lias are largely 

 developed on the French side, and are found on the Italian slope 

 also. During the deposition, the eastern portion of the chain was 

 raised and the western depressed. The succession of the Jurassic 

 rocks shows that the upheaval of the Alps was a slow, continuous 

 movement, with local oscillations. Sections of the Cretaceous rocks 

 are given, from which it is deduced that in Italy there is an unbroken 

 succession from the Oxfordian into the Neocomian ; whence the 

 writer concludes, that whilst in some parts of the earth there existed 

 modifying causes producing intermediate deposits, in other parts 

 free from disturbing causes the same fauna may have continued to 

 exist. The Eocene deposits south of the Alps are eminently littoral ; 

 and they are found northwards in the High Alps in a continuous line ; 

 here, also, they contain evidence of littoral conditions, and are ana- 

 logous to similar beds on the south side. 



Miocene beds are extensively developed in Venetia, but not in the 

 French or Swiss Alps, save in the Molasse of the plains, of which the 

 upper beds are Pliocene. 



The Quaternary deposits are divisible into ancient alluvium, gla- 

 cial deposits, and modern alluvium. Under the first division may 

 be placed" the frequently occurring debris of ancient lakes ; upon 

 this rest the striated boulders of the second period, as M. de Mortillet 

 has shown in his map of the old Italian glaciers : under the head of 

 " recent alluvium " are placed all the deposits formed subsequently to 

 the retreat of the glaciers, some of which contain the remains of 

 extinct Mammals. The author maintains that there has been but 

 one Glacial period, in opposition to the views of M. Scipio Gras and 

 M. Morlot, who have propounded the theory of the existence of two. 



The conclusions to which the author has arrived are expressed in 

 a table of correlations, which shows that the upheaval of the Alps, 

 effected during the Palaeozoic period, was succeeded by a submer- 

 gence during the Liassic ; and since that time the central portion has 

 been raised by a series of oscillatory movements extending through 

 all subsequent periods to the close of the Miocene, when the chain 

 attained its maximum height. There has been an intermixture of 

 the faunas on the Italian side, not only of formations immediately 

 succeeding one another, as of the Cretaceous and Eocene strata, but 

 also of others, such as the Oxfordian and the Neocomian. 



[S.E.P.] 



