Structure of the Eastern Alps. 311 



Alps*. But mineraloj^ical anomalies interfere with every extensive system 

 of geological arrangement, and in this instance throw no real dijfficulties in 

 the way of the classification here adopted. 



4. Older Alpine Limestone, representing the Lias and lower part of the Oolitic 



Series ? 



In the general, transverse section accompanying this paper the scale is so 

 small that the whole Alpine limestone series is represented by one colour : 

 but we adopt the three subdivisions of M. de Lill, as being founded on the 

 evidence of natural sections, and at the same time convenient for description f. 

 The present subdivision has its superior limits extremely ill defined ; but it 

 is supposed to include all the strata (often forming great bare precipices of 

 limestone) between the red sandstone and gypseous marls, and the parallel of 

 the upper saliferous breccias of the Alps. 



We stated in our published paper, that the lower Alpine limestone was 

 separated from the red sandstone and gypseous marls by dark beds of fetid 

 limestone alternating with shale : and having discovered specimens of the 

 Gryphcea incurva in the lower parts of this system near Bleiberg in Carinthia, 

 we ventured to conclude from analogy, unopposed by any conflicting evidence, 

 ""that the Alpine limestone, immediately overlying the red sandstone group, 

 commences on both sides of the chain with the lias." As, however, this con- 

 clusion does not accord with the published opinions of Dr. Boue and some 

 other writers on the structure of the Alps, we now proceed to notice other 

 groups of strata on the north flank of the chain (pointed out to one of the 

 authors by M. de Lill in the summer of 1830), which we are also disposed to 

 class vvith the lias. 



The red sandstone of Abtenau and Schaff'au dips unequivocally under great 

 masses of dark-coloured limestone and shale. These rocks are seen in the 

 mountains of Stub-berg and Schwarzenberg, and as they are well exposed in 

 the parallel valley of Gaisau, nearly due east of Hallein, and are there charac- 

 terized by organic remains, we proceed to give a detailed account of their 

 relations in that locality. These fossil strata are exposed beneath the village 

 of Crispel in a deep gorge of the Mertelbach, a tributary torrent of the Salza, 

 from the banks of which we obtained the following section J. 



I. Lowest beds, — bluish and greenish marls, with stone-bands of greyish, 

 calcareous grit. 



* Phil. Mag. and Annals, N. S. vol. viii. p. 93. \ See Plate XXXVI. fig. 1. 



+ See Plate XXXVI. fig. 2. 



