76 



of which the colour is always very deep, though 

 in a less degree than that of the transition lime- 

 stone *. The first of these formations consti- 

 tutes the Cuchivano, the nucleus of the Impos- 

 sible, and in general the whole group of the 

 mountains of New Andalusia. I saw no petri- 

 factions in it ; but the inhabitants assert, that 

 considerable masses of shells are found at great 

 heights. The same phenomenon occurs in the 

 country about Saltzburg *f~. At the Cuchivano 

 the alpine limestone contains beds of marly 

 clay %, three or four toises thick ; and this geo- 

 logical fact proves on the one hand the identity 

 of the alpenkalkstein with the zechstein of Thu- 

 ringia, and on the other the affinity of formation 

 existing between the alpine limestone and that 

 of Jura The strata of marl effervesce with 



* Escher, in the Alpina, Vol. 4, p. 340. 



f In Switzerland, the solitary beds of shells, at the height 

 of from 1300 to 2000 toises, in the Jungfrauhorn, the Dent de 

 Morcle, and the Dent du Midi, belong to transition limestone* 



{ Mergelschiefer. 



§ The Jura and the Alpine limestone are kindred forma- 

 tions, arid sometimes difficult to distinguish, where they lie 

 immediately one upon another as in the Apennines. The 

 alpine limestone and the zechstein, famous among the geolo- 

 gists of Freiberg, are identical formations. This identity, which 

 I noticed in the year 1793, (Ueber die Grubenwetter) is a geo- 

 logical fact, so much the more interesting, as it seems to unite 

 the northern European formations to those of the central chain. 

 It is known, that the zechstein is situate between the muriatife- 

 ous gypsum and the conglomerate (ancient sandstone) ; or 



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