Structure of the Eastern Alps. 317 



upper saliferous series is ill defined^ the base of the younger Alpine limestone 

 cannot in all cases be precisely limited. We may, however, state in general 

 terms — that the formation is very extensively developed — that it exhibits all 

 the irregularities of structure and position peculiar to the calcareous zone — 

 that it now and then rises into peaks of peculiar, fantastic forms, becomes 

 crystalline, and loses nearly all traces of stratification ; in which cases it is 

 often dolomitic — and lastly, that it cannot in general be distinguished, by its 

 subordinate minerals or its structure, from the lower division of Alpine lime- 

 stone. 



It is not our intention in such a sketch as this to enter on any details re- 

 specting these phenomena, for an account of which we must refer to works 

 expressly devoted to descriptions of the Alpine chain, and especially to the 

 various essays of Dr. Boue*. We shall, therefore, confine our remarks to a 

 brief notice of one or two localities, where the characters of this part of the 

 series are Avell exposed. 



The crystalline structure of the younger Alpine limestone is seen in the 

 mountains on the east side of the Traun-see, where, from the red, encrinital 

 limestone near Ebensee (which may be assumed as the base of the series in 

 the absence of the saliferous deposits) to the grey precipices of the Traun- 

 stein, the whole system appears to have undergone some great modification 

 since the period of its first deposition. 



At Aussee the system we are describing, is remarkable for the great deve- 

 lopment of a compact, dull grey, thin-bedded limestone, containing numerous, 

 black, siliceous bands and concretions, and with subordinate strata abounding 

 in several species of Terebratulge. Rocks of this kind range over the salt 

 deposit, occupying a great part of the Sandling and Loser Mountains, and 

 are well exposed in the Leissling Wand. 



Among the formations of the Untersberg, a similar, grey rock is overlaid by 

 a variegated and brecciated, subcrystalline limestone, largely cjuarried under 

 the name of Salzburg marble ; and the marble is surmounted by a grey hip- 

 purite-limestone. 



In our published sections, the younger Alpine limestone is represented as 

 entirely occupying a broad zone, including several successive ridges between 

 the line of the salt deposits and the northern outskirt of the chain. After 

 what has been above stated, it is obvious that this representation can only be 



* Dr. Boue states, that dolomite prevails more in the upper groups of Alpine limestone than 

 in the lower. Our own observations, as far as regards the Tyrol, were in accordance with this 

 remark. In the Salzburg Alps this variety of limestone is much more rare. — See some remarks on 

 the Ichthyolites of theSeefeld, by one of the authors (Phil. Mag. and Annals, N.S., vol. vi.p. 36.). 



