254 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DcC. 13, 



Savoy, M. Favre believes that tlie flysch is as independent of the 

 nummulite rock as the latter is of the pre-existing limestone ; whilst, 

 if the above-mentioned instance at Thones in the same region was 

 not sufficient to prove the contrary, I have shown by many other 

 examples, that nummulite rocks and flysch constitute one and the 

 same natural group in which no general severance has taken place. I 

 recur to this point, because several continental geologists have insisted 

 on the establishment of the *' independence " of formations by an 

 amount of unconformity which in my opinion is simply due to partial 

 dislocations and overlappings of the strata. Now, it is quite mani- 

 fest from the examination of any large region, that movements of the 

 subsoil have occurred in one tract both during and after the accu- 

 mulation of a deposit, which extending their influence to a certain 

 distance only, have not interfered with the continuous succession of 

 the same deposits in a neighbouring country. Changes of level at 

 various periods, accompanied by contortions and breaks, have often 

 produced those transgressions from which *' independence " is as- 

 sumed ; whilst in following out these very masses into other tracts 

 a clear and conformable succession is developed. English geologists 

 need, in truth, no caution on this head, for the phsenomenon is well 

 known to them, and it has been recognised on the grandest scale 

 in North America, through the labours of our associates of that con- 

 tinent. 



Is there then no formation in the Alps so completely and univer- 

 sally broken off^ from all other deposits that it is really independent 

 of them all ? As to the oldest sedimentary rocks of the chain, it is 

 unquestionably true that some of them (all those at least which are 

 affected by a rude slaty cleavage) are so essentially distinct from the 

 deposits which followed, that we may fairly suppose that they ac- 

 quired their mutations in an earlier epoch. The most distinct, 

 however, as well as the grandest of the examples of true indepen- 

 dence, is that of the molasse and nagelflue of Switzerland, to whose 

 position so many references have been made. As relates to Switz- 

 erland and all the northern face of the Alps, these deposits appear 

 to have been so completely dissevered from all pre-existing strata, as 

 to leave a considerable geological vacuum between them and the eocene 

 group. It has accordingly been seen, that there is a vast difference in 

 the fossils of the nummulitic group of that chain and those of the suc- 

 ceeding molasse, a diflerence which induces me to class the latter 

 rather with the older pliocene than with the miocene. But when 

 we turn to the southern flank of the chain, we there find, as I have 

 shown, an apparent conformity from the cretaceous rocks through 

 both eocene and miocene into the pliocene, although the axial line, 

 it is to be recollected, is perfectly parallel to that of Switzerland 

 and Bavaria, where the great hiatus exists. In the Italian case, I be- 

 lieve that another parallel elevation, posterior to the great upheaval 

 of the eocene, raised the external fringe of younger tertiary rocks 

 into the hills of Bassano and Asolo. In treating of Italy and the 

 Apennines, I shall, indeed, endeavour to show that those portions of 

 the sections of the tertiary series which are either denuded or imper- 



