256 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC, 13, 



age, and parallelism of masses which were formed at different epochs, 

 and in both regions we trace the disturbance and transgression of 

 certain strata in one tract, and their inosculation and quiet transition 

 in another. 



In the preceding pages I have endeavoured to present one general 

 view of the successive formations of the Alps, from the earliest periods 

 in which there are traces of life, until that grand rupture occurred, by 

 which the youngest tertiary deposits of the north flank of the chain un- 

 derwent those tremendous movements, which left them in their highly- 

 inclined and apparently inverted positions. With the exception of the 

 evidences of a very limited terrestrial vegetation afforded by some of 

 the older strata, and again by the lower portion of the eocene or num- 

 mulitic group (which can be accounted for by vegetable matter having 

 been drifted into bays or estuaries), nearly all the sedimentary rocks be- 

 speak, through their imbedded organic remains, a continuous accumu- 

 lation under the sea. Passing by for the present the palaeozoic rocks 

 and the trias, as yet only known in the Eastern Alps, and limiting our 

 attention to the Western Alps, we cannot view the grand succession 

 of Jurassic, cretaceous and nummulitic formations without perceiving, 

 that although some of them were unquestionably formed in shallow^ 

 water, even these must have been depressed to very great depths in 

 order to account for the copious and continuous superposition of 

 other and younger marine deposits of vast thickness. In appealing 

 to the serie«! of natural-history records as written on the walls of the 

 Alps, we find that extensive and sometimes entire changes in the 

 animals of these seas took place, even when the beds in which their 

 relics are now entombed appear to have succeeded each other without 

 any general physical fractures or derangements of the then existing 

 surface. In no case is this so remarkable, however, as when the 

 nummulitic or eocene group surmounts by conformable transition 

 the uppermost member of the cretaceous system. 



At length, however, a period arrived, when all these great masses, 

 which for the most part had hitherto been in a submarine condition, 

 were elevated and desiccated, so as to constitute terra firma., probably 

 in the form of a rocky and abrupt island. It was this land, of whose 

 altitude we can now form no accurate idea, which furnished the 

 pebbles, sand, marl and other materials which compose the molasse 

 and nagelflue. The absence of all links to connect this molasse of the 

 Northern Alps mth the pre-existing eocene strata coincides, therefore, 

 with the facts, that, owing to disturbance and elevation, the older ter- 

 tiary strata constituted terrestrial masses, before the earliest-formed 

 pebbles or sand of the nagelflue were deposited. In this way the 

 vast hiatus between the one set of rocks and the other is well ex- 

 plained. In examining the m.olasse, we are assured by its fossil remains, 

 whether animal or vegetable, that during the very long period which 

 must have elapsed during its increment, the climate must have been 

 much warmer than that of the same region in the present day. The 

 arborescent palms and intertropical plants which then grew upon the 

 adjacent lands of the Alps and the Jura, the rhinoceros and other 

 large herbivorous quadrupeds which browsed upon them, the large 



