280 



THE WONDERS OF GEOLOGY. Lect. IIL 



a great height, and not in the intermediate plain. These 

 inductions are so evident as to require no comment. 



The ancient alluvial deposit called the Loess, is a fine 

 loam, containing fresh-water and land shells of many- 

 existing species ; a few bones of the horse and mammoth, 

 are the only mammalian remains that have been discovered.* 

 From the extensive distribution of this bed, and its occur- 

 rence at various elevations — in some instances on the flanks 

 of mountains 1,200 feet above the level of the sea, at others 

 spread out over the gravel of the vast plain of the Rhine — 

 it is inferred, that although the loess has been deposited 

 since the existing system of the hills and valleys of the 

 country, yet great changes must have subsequently taken 

 place in the physical geography of the district ; and 

 Mr. Lyell states that there is reason to conclude, that 

 since the deposition of this fluviatile loam, all the land 

 between Switzerland and Holland has suffered a subsidence, 

 and a subsequent elevation, to the amount of many hundred 

 feet. 



56. Other tertiary strata of Europe, North 

 America, &c. — It has already been mentioned, that strata 

 referable to the period comprehended between the upper- 

 most secondary formations and the human epoch, occur 

 throughout Europe ; presenting in some instances well- 

 defined groups, with marked boundaries, and in others, vast 

 areas, over which the deposits are irregularly spread. The 

 geographical relations of the tertiary strata to the exist- 

 ing lands and seas, is an interesting subject of inquiry, but 

 on which my limits forbid me to enter. f I may, however, 

 observe, that Europe must have possessed many of its most 

 striking physical characters at the commencement of the 

 eocene period ; and that its present configuration has been 

 produced by the conjoint effect of successive mutations in 



* Principles of Geology, vol. iv. p. 33. 



f Mr. Lyell's Principles of Geology should be consulted. 



