204 



FORMATIONS OF T H F, 



nummulitic limestone, an enormous thickness of overlying strata of dark-coloured 

 slates, marlites, and fucoidal sandstones, provincially called Flysch, must be re- 

 garded as lower eocene." 



And in another place, speaking of the epoch of the underlying nummulitic lime- 

 stone, whether it should be referred to the cretaceous (chalk formation) or tertiary, 

 we find the following : — 



" M. Bou£ indeed announced, in 1847, his own conviction, that the nummulitic 

 rocks belonged to the eocene or lower tertiary period, and remarked, in a paper 

 read to the French Geological Society in that year, how much delight Alexander 

 Brongniart would have experienced, had he lived to see one of his boldest and most 

 startling generalizations thus crowned with success. Alexander Brongniart had in 

 fact declared, many years before, that the shells of the summit of the Diablerets, 

 one of the loftiest of the Swiss Alps, which rises more than 10,000 feet above the 

 sea, were referable to species characteristic of the eocene tertiary of the neighbour- 

 hood of Paris." 



:i: * * * * :;: 



" Were we to endeavour to estimate the changes in physical geography which 

 can be proved by the position of these marine eocene strata to have occurred since 

 the commencement of the tertiary period, we should find them to be very inade- 

 quately expressed by stating, that they equal in amount the conversion of sea into 

 land of a continent as large and lofty as that of Europe, Asia, and the north of 

 Africa. I endeavoured, in 1834, in a map constructed for the 3d edition of my 

 ' Principles of Geology,' to show the extent of surface in Europe, and part of Asia, 

 which had been covered by water, at some time or other, since the beginning of the 

 eocene period. But, had I been then aware, that a true pictorial representation of 

 such modern revolutions in physical geography would have required the submer- 

 gence of the Alps, Pyrenees, Apennines, and Carpathians, and the insertion of a 

 few insignificant islands only in their place, I might have thought such an illustra- 

 tion superfluous or without meaning, and been satisfied by simply insisting on the 

 post-eocene ubiquity of the ocean — not, indeed, by a simultaneous, but by a succes- 

 sive occupancy of the whole ground. But how small a portion even of the super- 

 ficial remodeling of the earth's crust in recent times is expressed, by declaring that 

 we can establish, by direct proof, or legitimate inference, the upheaval out of the 

 sea of all the land in Europe, Asia, and part of Africa ! During the same tertiary 

 periods, there have been vertical subsidences as well as elevations ; and we have 

 every reason to believe, that the larger part of the globe (comprising nearly three- 

 fourths of its superficies) which is covered with water, has undergone, in equal 

 periods of time, oscillations of level not inferior in degree to those to which the con- 

 tinental spaces have been subjected. If, therefore, we were to confine our thoughts 

 to the mere outward modifications, in the shape of the land or bed of the sea, and 

 all the changes of climate and fluctuations in organic life inseparably connected 

 with movements which have amounted, in some cases, to more than two miles ver- 

 tically in one direction, besides the lateral displacement of rocks and their denuda- 



