1S48.] 



MTIRCHISON ON THE STRUCTURE OF THE ALPS. 



195 



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•?Ploq 



•U3M3S 



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M 



the upper greensand (c) and the nummuhte 

 rocks (/), is precisely in the same place as the 

 inoceramus limestone of Thones in Savoy 

 before described, and that both are clearly re- 

 presentatives of the white chalk of iNorthern 

 5 Europe. 



g This sewer-kalk rises up on nearly all sides 



H of the beautiful valley of Schwyz. I refer to 

 ^ it the grand red and white peaks of the My- 

 ^ then*, which overlook the town of Schwyz, 

 so well known to all lovers of the picturesque. 

 These masses of red and mottled grey and 

 white limestone strongly resemble the scaglia 

 or Italian equivalent of the chalk, and have 

 ^ . no sort of resemblance to any other known 

 S;| limestone in the Swiss Alps. They also 

 I § clearly overlie all the older limestones, ju- 

 g ^ rassic and neocomian ; I therefore unhesi- 

 S S3 tatinglv refer them to the white chalk ; and 

 !►§• the more so because they are linked on to 

 ^^ the superior nummulitic and flysch forma- 

 tions. On the northern flank of the smaller 

 peak, in ascending to the Hacken pass, we 

 crossed over masses of schist and impure 

 limestone with white veins, which formed the 

 external envelope of the slope, and next over 

 g green-grained calciferous grits with Nummu- 

 S lites planospira, N. rotularis, N. Biaritza- 

 =i na, and Orbitolites discus ; the thick shells 

 S of the latter resembling little layers of calc- 

 I spar ; but we also detected a specimen of 

 ^ Inoceramus in the fragments of limestone 

 which had fallen from the cliifs. The up- 

 heaval, however, of the Mythen has been ac- 

 companied by so much dislocation around it, 

 and such enormous subsidences have taken 

 place on the taluses, that no regularity of 

 succession can be detected ; nor could the 

 above order be stated if the adjacent rocks 

 when in their normal positions (as before 

 cited in fig. 11) had not afforded us a true 

 key to the structure of the tract. There 

 is, in fact, just the same appearance of a 

 general inversion of the formations on the 



* We passed the Mythen on the north by the 

 Hacken pass in our route to Einsiedeln and retm-ned 

 by Brunnen and the Holzeck pass. The latter is 

 the grandest scene, and is the point from whence 

 the summit is alone accessible. 



