Geohgy of the Austrian Alps. 37 



in its position, nature, and fossils. Besides, the small number of 

 similar petrifactions is of no consequence, because this accident 

 can be explained by placing both deposites in the chalk, as well 

 as by classifying both in the tertiary soil. But most concholo- 

 gists and geologists still consider the bacculite limestone of 

 Maestricht and of Valognes, which resembles that of the Danish 

 Isles, as a part of the chalk formation. 



After having considered the deposite of Maestricht, we re- 

 turn to the reasoning, apparently fair, tJiat the tertiary soil ap- 

 pears always to be separated from the chalk by a break. Our 

 adversaries forget that there are a good many similar cases in 

 geology. Thus, in certain basins, the old alluvium (diluvium 

 of some English geologists) occupies a higher level than the 

 modern alluvium ; the two deposites are not intermixed either 

 by transition or alternation ; because, probably, sudden rup- 

 tures, various catastrophes, have occasioned a sudden sinking of 

 the level of the water during the alluvial period. Besides, how 

 many formations, deposites, and even beds, are not placed in un- 

 conformable and overlying stratification, the one upon the other, 

 in consequence of accidents occasioned by upheaving, slipping 

 down, and total overturning, which have affected the inferior 

 masses, before the deposite of the superior ones ? The case of the 

 chalk seems to us a very simple one, for we do not see the ne- 

 cessity of its being connected, at least in Europe, with the tertiary 

 soil; at the same time, we do not deny that such may be the case 

 in other parts of the world : allowing such a possibility, we do 

 not see the necessity for a new and unknown formation to effect 

 such an insensible transition. We agree with many eminent geo- 

 logists in thinking that, in Europe, the termination of the chalk 

 period was characterized by tremendous catastrophes; whole 

 chains of mountains have been heaved up, immense lines of 

 volcanic eruptions first made their appearance, and in conse- 

 quence most dreadful and great ruptures took place, and whole 

 continents were thrown up. In this way, the sea would leave 

 dry a great part of the countries it formerly covered, and the 

 deposites formed under its surface, or along the shores, would 

 naturally occur in unconformable and overlying stratification, 

 sometimes in gulfs surrounded by steep chalk-cliffs, sometimes in 

 primary or secondary creeks. The immense changes that took 



