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



the nummulitic strata (/) which are incUned at an angle of about 45°, 

 may really pass under the truncated edges of the lower neocomian 

 hmestone («) m the manner represented. In fig. 19 the beds of flysch 

 of the Bolghen may be similarly overlapped by the neocomian lime- 

 stones of the Schwartzenberg in a similar manner, though probably the 

 angle of the line of fault is different from that at Dornbirn. In both 

 these cases, as in many others throughout the Alps, where the press- 

 ure has been so exerted from the centre towards the flanks of the 

 chain as to invert the axes of a series of formations originally con- 

 formable, the law or rule of Professor Rogers may be found to apply. 

 On the other hand, a different method of reasoning may be neces- 

 sary, in reference to the great Swiss fault between the molasse and 

 all pre-existing rocks (see figs. 12, 13, 14, 17, &c.) ; for in no case 

 was the molasse and nagelflue originally superposed conformably on 

 the pre-existing strata out of which it has been formed. These older 

 strata must, in fact, have undergone many of their contortions before 

 the molasse was accumulated on their flanks, and in no instance can 

 the latter be observed in conformable undulation with the former. 

 In no case (as far as I know) do the molasse and nagelflue partake 

 of any fold which has affected the older rocks. On the contrary, they 

 are always abruptly truncated against such older strata, and more fre- 

 quently with an inverted dip than otherwise. It is indeed manifest 

 from the composition of the nagelflue, that when it was formed, the 

 secondary rocks of the Alps, and even the nummulite rock and flysch, 

 were hard solid masses ; in fact, just in the lithological state we now 

 find them. Again, we cannot look at the sections on the flanks of 

 theRigi, HoherSentis, &c. (figs. 12, 13, 14, pp. 195, 197, 200, &c.), 

 where the upper conglomerate of the molasse is forced into inverted 

 and unconformable contact with the older rocks, without perceiving 

 that the great anticlinal of the regenerated and younger strata (m) is 

 vertical, and not inverted as in the older and folded rocks. And this 

 fact teaches us, that the forces which upheaved the molasse and 

 nagelflue were independent of those which contorted and produced 

 the earlier fractures in the chain. 



But whatever view we may take, the phoenomena of the group of the 

 Hoher Sentis present us with very remarkable problems not easily re- 

 concilable (see PI. VII. p. 243). Whetherviewed from the plains around 

 the lake of Constance, or examined in its precipitous and rugged sides, 

 few geologists would doubt that this cluster of mountains had taken 

 up its position relative to the lower country by a great upcast*. Yet 

 nowhere within it has M. Escher been able to detect anything like 

 a centre of upheaval, still less any motive cause of elevation ; for 

 the highest summit is not composed of the oldest rock of the chain, 

 viz. the lower neocomian («), but, on the contrary, of the equivalent 

 of the chalk {d). Its remarkable features are rapid folds (doubtless 

 accompanied by some considerable faults), by which, in fact, the 



* In my section I have hypothetically drawn the line of the great fault between 

 the molasse and the older rocks nearly vertical, but whether it inclines away from 

 the chain, according to the usual form of upcasts, or continues to pass under the 

 older rocks, is not known. 



