Structure of the Eastern Alps. 313 



the whole calcareous zones of the Alps, and shut them out from any com- 

 parison with our great secondary groups. It is at least probable, that the 

 distribution of organic forms, during ancient periods in the history of the 

 earth, was governed by the same laws which regulate their distribution in the 

 existing seas. Hence, in cases where contemporaneous formations are widely 

 separated from each other, and have been deposited under widely different 

 circumstances, we have no right to look for any thing more than a o-eneral 

 accordance in the characters of their fossils : and we venture to assert, that 

 there is this general accordance between the fossils of the great secondary 

 groups of the Alps, and those of certain corresponding groups in England. 



The lias-like shale and limestone of Gaisau, above described, are overlaid 

 on both banks of the Mertelbach by a deep red-coloured limestone, distin- 

 guished by a multitude of broken stems of Encrinites, together with some 

 Ammonites, Belemnites, casts of bivalves, &c. This limestone is largely de- 

 veloped in the great valley of the Salza, on the west side of which it ranges 

 beneath the salt deposit of Hallein, and on the east side it is extensively 

 quarried at Wiesthal as well as some other places. Thence it ranges to the 

 east, and reappears in several valleys : we particularly observed it at the 

 southern end of the lake of Halstadt, and again in the neighbourhood of 

 Aussee. In no place, however, is the position of this rock better seen than at 

 Gaisau, where it surmounts the black shale, and is in its turn covered by a 

 grey limestone, forming the higher ridges of the Schnittenstein *. 



Near Aussee the red, encrinital limestone is well exhibited in the small, 

 elevated valley of Wiesau, about one league above the salt works, forming a 

 conical hill called the Brunn Kogel ; the eastern flank of which is washed by 

 a rapid torrent, separating it from the Pissenstein. The latter mountain is 

 chiefly made up of deep-coloured shale, containing bands of flinty, black slate, 

 approaching in character to Lydian-stone, and much resembling the altered 

 shales of the lias in the south coast of Mull and other parts of tiie Hebrides. 

 All the strata in the Pissenstein are much contorted, highly inclined, and dis- 

 located, so that their exact relations to the red limestone of the Brunn Kogel 

 are not clearly seen : but as similar, black shale and subordinate, flinty beds 

 occupy the base of the adjoining mountains of the Loser and the Sandling, 

 and appear to plunge beneath the salt beds of Aussee, we are disposed to 

 refer them to the above-described lias group of Gaisau. 



The section of the Brunn Kogel not only shows the red, encrinital lime- 



* See Plate XXXVI. fig. 2. 

 VOL. III. SECOND SERIES. 2 S 



