32 GEOLOGICAL MEMOIRS. 



of the Rhine ; pecuUar organic remains, different from anything we 

 got a notion of from the Dauphine and Savoy thoughout the north- 

 ern calcareous zone of the Swiss Alps, compel us to search elsewhere 

 for points of comparison*." One of the most remarkable facts,, 

 recently ascertained by M. Escher von der Linth, is the sudden 

 termination of all these formations along the valley of the Rhine, 

 between Chur and the Lake of Constance. The Swiss geologists sup- 

 pose the inferior oolite of the Calanda to immediately follow rocks of 

 a far older epoch ; the mighty masses of triassic and liassic rocks, so 

 conspicuous on the opposite side of the Rhine, are completely missed 

 on this place ; the correspondence of these phaenomena with the dis- 

 cordance between the upper lias and the inferior oolite, as observed in 

 -everal of our Austrian localites, is very striking ; and perhaps one 

 )f the most violent upheavings of the eastern Alps may be referred 

 to this period. 



Another mass never covered by liassic waters is what may be 

 called the " Bohemian continent," which comprises not only Bohe- 

 mia by itself, but also the whole of the granitic and gneiss rocks 

 forming table-lands throughout the larger part of Austria, northwards 

 of the Danube, between Passau and Krems, frequently appearing on 

 this side of the Danube also and near St. Leonhard, not far from 

 Pochlarn, advancing their southern extremity to a distance of only 

 one and a half geographical miles from tlie alpine limestone. When 

 treating of the Gresten strata, we shall speak of the necessary influ- 

 ence of so extensive a continental mass on the fauna of the neighbour- 

 ing seas ; its farther influence on the elevation of the Alpine rocks, and 

 how far the flexure of the northernmost tract of variegated sandstone 

 depends upon its outline, must be cleared up by future investigations. 



We cannot leave our subject without some allusion to the crys- 

 talline rocks of the central eastern Alpine chain, standing in im- 

 mediate relation to the Alpine limestones. At present the ques- 

 tion of the existence of a continent above the level of the sea on the 

 place now occupied by these mighty mountains, can scarcely meet 

 with a satisfactory answer. The majority of facts are opposed to 

 it ; at all events it may not have formed a continuous mass ; who- 

 ever has wandered through one of the principal valleys, separating 

 the central chain from the Alpine limestones, may easily agree with 

 this opinion. On one side, the crystalline slates, whose rounded 

 slopes are covered with forests, and frequently cut through by 

 parallel secondary valleys, amply provided with water, tower higher 

 and higher up to the mighty masses of the Grassglockner, Anthogel, 

 &c., giving a magnificent background to the whole scenery ; the 

 opposite slope of the valley offers a great contrast by its vertical 

 limestone cliffs, arising suddenly to the height of many thousand feet 

 amidst the variegated sandstones, covered with meadows and di- 

 spersed human habitations. These natural walls, rivalling in white- 

 ness the snow that covers the tops, run through a line of several 

 German miles without being interrupted by any secondary valley ; 

 the strata are all broken up, and where should their continuation 

 * Geol. d. Schweitz, vol. ii. p. 196. 



