92 Prof. Sedgwick and Mr. Murchison on the 



3. Red and variegated Sandstone and gypseous Marl; some- 

 times with subordinate Beds of fetid Limestone, Rauch- 

 tvacke, fyc. S)C. 



This deposit is, we believe, found nearly throughout the 

 whole extent of the eastern Alps overlying the transition 

 series, and forming the base of the great precipices of the 

 older Alpine limestone. Its characters are so peculiar, and 

 its continuity is so remarkable, that, independently of its im- 

 portance as a term of comparison with other regions, it would 

 well deserve a separate notice. — On the northern side of the 

 transition system of the Alps, the red sandstone is exposed in 

 a series of longitudinal valleys, and overlies nearly all the 

 principal deposits of sparry iron ore, of which we have already 

 pointed out the general range. 



From Werfen on the Salza to Hairing on the Inn, it ranges 

 in the position we have indicated, forming a succession of 

 red terraces ; and, in consequence of a great increase in the 

 thickness of the subordinate fetid limestone, spreads out into 

 a succession of low ridges of hills ranging parallel to the 

 escarpment of the Alpine limestone. On the west side of the 

 Inn it is no longer visible, in consequence of the great dislo- 

 cation pointed out above, which brings the higher beds of 

 the calcareous zone into contact with the central axis. 



On the south side of the central axis the deposit has the 

 same position, and we believe also the same continuity; and it is 

 well exposed in the valley between Ponteba and Tarvis ; also 

 on both sides of the Bleiberg hills, as is indicated in our trans- 

 verse section. — In order to convey some notion of the struc- 

 ture of this formation, we proceed to notice one or two sec- 

 tions on both sides of the chain, where it is well exposed. 



In describing the succession of deposits on the banks of 

 the Salza, we have already pointed out certain beds of close- 

 grained grauwacke sandstone and variegated marls, which 

 seemed to form a passage between the true transition system 

 and the red sandstone. About half a mile south of Werfen 

 are some quarries in the secondary series, exposing the fol- 

 lowing succession of beds in the ascending order : 



(1.) Irregular masses of red conglomerate with rounded 

 pebbles of the older rocks. (2.) Black, calcareous shale pass- 

 ing into dark smoke-gray, fetid limestone, the whole irregu- 

 larly traversed by veins of gypsum. (3.) Argillaceous beds 

 striped with parallel, red bands of gypsum. (4.) A thick, ir- 

 regular cellular bed with much hydrate of iron, thin veins of 

 gypsum forming reticulations through the mass. (5.) A mass 

 composed of several beds of gypsum, finely granular, but not 



fibrous, 



