1848.] MURCHISON ON THE STRUCTURE OF THE ALPS. 1C9 



the transition or palseozoic rocks. In the general map before alluded 

 to, I roughly sketched such a zone both on the north and south 

 flanks of the transition rocks, and its presence has since been laid 

 down in greater detail by M. Morlot in his useful general map of the 

 Austrian iVlps* ; though I cannot admit his suggestion that such red 

 rocks can be equivalents of the Rothe-todte-liegende. 



The red sandstones (occasionally with certain yellowish limestones 

 and also with salt and gypsum), which my colleague and self de- 

 scribed in precisely the same geological position in the northern 

 portion of these Alps, are, I have no doubt, of similar age to those 

 described in the South Tyrol and Venetian iVlps. 



The researches of the palaeontologist in the associated limestones 

 have, indeed, to a great extent set that question at rest. M. von Hauer, 

 jun., of Vienna, has shown that some of the fossils in the Salzburg 

 Alps are identical with those which occur in the South Tyrol in the 

 environs of Castel Ruth, St. Ulrich and St. Cassian ; thus establishing 

 the existence of true muschelkalk types in the northern zone, where 

 they had not before been recognized. Among the fossils common to 

 both tracts is the Aimnonites Johannis AtistricB (Hauer). 



Whether any true triassic plants occur in strata of that age in the 

 central escarpments of the north-eastern Alps, is unknown to me. But 

 the discovery of them in certain places near Waidhofen and Steyer, 

 either in the middle of the area occupied by the secondary limestones 

 or at their northern edge, has led to a classification on the part of 

 the eminent mineralogist Haidinger, which, with every respect for 

 him, I would suggest is not founded on a sound geological basis. 

 The Calamites arenaceus, Pterophyllum longifoliwn, &c. (identified 

 as such by Dr. Unger of Gratz) have, indeed, been found in a sandstone 

 which dips under the liassic and Jurassic limestones of the chain, and 

 such keuper plants are therefore incontestably in their right position. 

 Now, as this sandstone resembles some of the sandstones with im- 

 pure limestones, that constitute a great zone geographically ex- 

 ternal to the whole of the alpine limestone, and to which the name 

 of " fly sell " has been applied, and of which the " Wiener sand- 

 stein" is the prolongation, M. Haidinger has identified the one with 

 the other, and in consequence has recently coloured as " keuper," 

 the whole of the flyschf . This zone of rocks is that which, often 

 afl'ected by great longitudinal faults, appears to dip under the alpine 

 limestone, and had been classed as the uppermost secondary mass 

 of the Alps. It is this very zone to which I am about presently 

 to call attention in detail as belonging to much younger deposits. 

 If the enormous thick accumulations of grits, limestones and fucoid 

 schists to which I now allude, had a real existence beneath the 

 lias where the strata are not inverted, then surely such rocks would 

 somewhere be seen in the well-exposed natural escarpments near 

 the base of those secondary rocks which lie in their normal posi- 

 tions. Such, indeed, is the position of the trias above described. 



* See also the octavo volume accompanying the map by the same author, 

 " Erlauterungen zur geologischen Uebersichtskarte der Nordostlichen Alpen, von 

 A. V. Movlot." 



t See the new Geological Map of the Austrian Empire. 



