Structure of the Eastern Alps. 309 



lines of the longitudinal valleys at the base of tlie great escarpments of the 

 calcareous zones. More recent observations have, however, shown that it 

 occasionally reappears in other longitudinal valleys further removed from 

 the central axis, being sometimes brought into unconformable contact witii 

 deposits of a much younger age. This is clearly seen in the country south of 

 Salzburg : for the red sandstone, which at Werfen dips under the Alpine 

 limestone of the Tannen Gebirge, is either by a great flexure or by a break 

 reproduced in a parallel valley, extending from GoUing to Abtenau, where it 

 passes on one side under a slaty, black limestone and shale, which are, for 

 reasons hereafter to be given, referred to the lias ; whilst on the other side of 

 the valley it abuts against the shelly deposits of the adjoining valley of Gosau*. 



The same deposit reappears in like manner in other longitudinal valleys ; 

 a fact which seems to prove that during some period of elevation were pro- 

 duced a series of enormous breaks or flexures, ranging nearly in the direction 

 of the principal axis of the neighbouring region of the Alps : and the paral- 

 lelism of these lines of dislocation confirms, at least in part, some of the great 

 views published in the researches of M. Elie de Beaumont, which will be 

 referred to more than once in the subsequent portions of this paper. 



This formation of red sandstone may be traced in great detail in the valley 

 of the Lammer, between Golling- and Abtenau. At Schaffau the slaty beds 

 contain imperfect casts of bivalves, and bosses of gypsum, with much iron 

 glance here and there scattered through them. Near this place there is also 

 a small protuberance of basaltic greenstone, a rock of very unfrecjuent occur- 

 rence in these regions ; but, unfortunately, the thick covering of detritus, 

 and the vegetation which surrounds it, make its immediate relations obscure. 

 The limestone nearest to it on one side is dolomitic ; and the strata of red 

 sandstone on the other dip away from it to the east, passing under the black 

 shale and dark limestone of the Stub-bergf. The greatest extent of denu- 

 dation of the red sandstone is in the bowl-shaped valley of Abtenau ; and 

 there the banks of the Lammer present very fine sections of gypsum, the mi- 

 neral being seen, for the distance of several miles, in most of its modifications, 

 forming cliffs of 100 and 150 feet in height; in one place made up of gypseous 

 and brecciated clays, in another of finely laminated gypsum and marl, and in 

 a third of compact and thick-bedded gypsum, approaching in character to 

 common alabaster. 



* See Plate XXXVI. figs. 2 & 10. 



f These rocks, and some, hereafter to be described, in tlie Bavarian valley of Sonthofen, are 

 the only examples of igneous rocks, in the northern calcareous zone of the Alps, which fell under 

 our observation. 



