1848.] MURCHISON ON THE STRUCTURE OF THE ALPS. 245 



or in other words, the prolongation of the great synclinal occupied by 

 the Alpnach branch of the Lake of the four cantons, is seen to consti- 

 tute a good massive synclinal-formed hill, the promontory of Biirgen, 

 in which the nummulite and flysch rocks are troughed on neocomian 

 and cretaceous limestones ; but if followed to the opposite side of the 

 lake to Viznau, viz. in the same direction (in the space of two or 

 three miles), that which was in a synclinal form has become the scene 

 of that grand fault or rupture by which the upper nagelflue plunges 

 against and apparently under the neocomian, almost to the exclusion 

 of the nummulite and flysch rocks, fragments of which only appear 

 (fig. 1 2, p. 1 95) . Following on this line to the N.E., across the lake of 

 Lowerz, the representatives of the nummulite rocks and flysch are in- 

 tercalated, though in a highly broken condition, between the molasse 

 and nagelflue of the Rossberg and the cretaceous rocks of the My then ; 

 whilst, still further to the N.E., these nummulitic rocks, so squeezed 

 up on the flanks of the Mythen, expand into the tracts south of 

 Einsiedeln, where I have mentioned them as having an inverted dip, 

 or towards the axis of the chain (fig. 13, p. 197). Thus, that which is 

 an overlap in one portion of the sides of a synclinal, and whereby an 

 enormous transposition or slide of the masses has occurred, often occa- 

 sioning the absolute destruction of copious formations along the line 

 of fracture, on another part of the same line is, as far as external 

 appearances go, a complete overthrow, in which the older rocks are 

 superposed to the younger. 



As the same physical relations of the rocks, whether in anticlinal 

 or synclinal forms, are seldom persistent for more than a few leagues, 

 and rarely in absolutely right lines, so but few of the longitudinal 

 faults are continued for great distances without interruption or 

 change in their conditions ; and although some of them pass across 

 transverse valleys without much deviation from their strike, it is not 

 unfrequent to see a considerable lateral displacement, or as it were 

 a movement '^en echellon," in masses occupying the opposite sides 

 of any broad transverse valley. In crossing the valley of the Rhine, 

 for example, near its "debouche" into the lake of Constance at Bre- 

 genz, in the direction or continuation of the synclinal flysch valley of 

 Wildhaus, we find a large outlier of cretaceous rock at Eschen on 

 the right bank, which is in fact an anticlinal of neocomian, flanked 

 by sewer-kalk or chalk, and trending N.E., whilst the chief trough 

 or synclinal of flysch setting on to the south of Feldkirch, trends de- 

 cidedly E.N.E. across the 111*. 



The great cretaceous masses of the Hoher Sentis are repeated or 

 continued, it is true, in a general way in the mountains of the Hohe 

 Kugel and the StaufFen (the insulated hill of Kamor in the valley of 

 the Rhine serving as a link between the opposite promontories) ; but 

 there the nummulite limestone, instead of being thrown off the cre- 

 taceous rocks, as in the Fahnern mountain on the left bank, as before 

 explained (fig. 1 5), is abruptly collocated with an inverted dip (fig. 1 6) 

 against a grand neocomian escarpment ; whilst between that junction 



* See Wiirl's Map of Switzerland, which is recommended strongly to all geo- 

 graphers and geologists. 



