1848.] MURCHISON ON THE STRUCTURE OF THE ALPS. 261 



containing cretaceous and Jurassic fossils ; whilst its southern limb 

 is composed of nummulitic rocks of eocene age resting on lias. 



Although I had not sufficient time at my disposal to determine 

 the detailed relations of all the strata between the external face of 

 the Tatra and the valley of Neumarkt, a section with which M. 

 Zeuschner favoured me sufficiently explains, that the flysch (g) 

 which overlies the nummuhtes, and dips to the north, is met by a 

 great mass of Carpathian sandstone, &c., which occupying the Giuba 

 Tavka, is inclined to the south in the manner represented in fig. 31. 

 Subjected to other fractures, this sandstone (probably its lower mem- 

 ber) is found a little further northwards to overlie conformably the 

 calcareous ridge (o) before spoken of, in the upper part of which 

 neocomian or lower greensand fossils occur, and whose lower division 

 is characterized by Oxfordian Jurassic forms. In this way I can 

 readily understand how the nummulitic rock (/) and its overlying 

 member {(/) should really be eocene, whilst the great mass of Car- 

 pathian sandstone (c) which is separated from the former by a 

 fault, may, as I have always thought, represent parts of the cre- 

 taceous system (upper greensand, &c. ?). I can also now well under- 

 stand how the equivalents of the lower greensand (a, b) should have 

 aiforded the above-mentioned characteristic fossils ; tJie whole re- 

 posing on an upcast outer ridge of Jurassic limestone. Having con- 

 vinced myself that the nummulitic rocks on the north flank of the 

 Tatra are eocene, I cannot doubt that the masses thereof which lie 

 on the south side of that chain are of similar age. Thus, the sec- 

 tions of M. Zeuschner would lead me to believe, that the nummulitic 

 rocks and overlying sandstones of the valley of Kradak, which he 

 considers to be Jurassic, are really the true eocene, which there re- 

 posing on lower Jura are trmicated against the granite of the higher 

 Tatra. Other nummulitic rocks are repeated to the south of the 

 lesser Tatra. 



For all these reasons I feel assured, that Professor Zeuschner has 

 erred in placing this nummulitic limestone in the Jurassic series, or at 

 the base of the whole external zone of the Carpathian sandstones and 

 limestones. For, whatever may be the age of the formation on which 

 this nummulitic rock reposes, its zoological characters are unmistake- 

 able ; whilst both on the north and south sides of the Tatra, it is 

 immediately covered by strata which represent the flysch. 



In the Carpathians, as in the Alps and Italy, great confusion has 

 arisen from deciding on the age of sandstones by their mere mineral 

 characters ; for, although it is manifest that rocks of this aspect and 

 containing fucoids clearly overlie the nummulitic limestone, there are 

 other cases, like those of Gosau and other parts of the Eastern Alps, 

 where the lithological characters of the eocene greensand descend far 

 into the cretaceous system. The highly contorted, broken and dis- 

 located region between Neumarkt and Rugosnik on the south and 

 Cracow on the north, over which I passed, affords a good illustra- 

 tion of this point, and also of the extreme difficulty, in the absence 

 of fossils, of being able to draw any neat line of demarcation between 

 some of these sandstones and schists. I have repeatedly noted, that 

 the presence of fucoids can never be accepted as any test of the age 



