1848.] MURCHISON ON THE STRUCTURE OF THE ALPS. 203 



under the great calcareous masses of the Stauffen*. On visiting this 

 spot Tvith Prof. Briinner I found dark greyish, white-veined limestone 

 with schist or shale in the mass now visible in situ, which, if the fossils 

 were omitted, would be " flysch," surmounted by other bands of 

 schist or shale and sandy green-grained limestone passing into a grey 

 rock, and again shale and schist with thin stone bands of " flysch." 

 In the lower limestone were small-ribbed Pectens, large Ostrese, 

 Terebratulse, Echini, and many Nummulites. The higher portion of 

 the upper band is characterized by Orbitolites discus and the Num- 

 mulites globosa. In the lower mass is the highly ferriferous band 

 formerly worked for iron, which is a perfect congeries of the Num- 

 mulina planospi7'a or assilinoides and N. placentula (Desh.). These 

 fossils are precisely those of the Fahnern mountain on the opposite 

 bank of the Rhine ; whilst in the association of iron with the nummu- 

 lites it is clear that it is the direct western extension of the still more 

 ferruginous zone of Sonthofen in Bavaria. 



These nummulitic and flysch beds apparently dip under the secon- 

 dary limestone. The mural escarpment of the Breitenberg, a coun- 

 terfort of the Stauffen, which seems to be the upcast mass, consists 

 chiefly of neocomian limestone, and in the part to which we ascended 

 with some difliculty through the thick woods we found the Spatangus 

 retusus of the lower member of that formation. It is probable that 

 there is really an overlap at this junction as represented in this wood- 

 cut, fig. 16, and the point will be discussed in the sequel. 



N. 



Fig. 16. 



Bi'eitenberg. 

 Dornbirn. /?,,^^^^^::^r>;^-- 



/ Fault. 



/. Nv mmulite rocks. 

 a. Neocomian (lower). 



Sonthofen Iron Mines, and the Griinten Mountain in Bavaria. — 

 The symmetrical order of succession so clearly exposed on the outer 

 flank of the Fahnern and at other points around the Hoher Sentis, 

 and which is obliterated along the great line of fault at Dornbirn 

 near Bregenz, is strikingly and instructively resumed in the Griinten 

 mountain, situated between Immenstadt and Sonthofen in Bavaria. 



Sections of this mountain were published in the communication so 

 often alluded tof, but they were defective in not presenting any well- 

 defined geological horizon either in the inferior or superior strata. It 

 is true that Prof. Sedgwick and myself then discovered greensands 

 with unquestionable British cretaceous fossils, and we stated that 

 these were surmounted by the scaglia or equivalent of the chalk. 

 But the transition downwards from that which really represents the 

 gault and upper greensand into the fossiliferous limestones, now 



* Trans. Geol. Soc. Lond. vol. iii., 2nd series, p. 325, and pi. 36. fig. 3. 

 t Ibid. pi. 36. fig. 4. 



