16 



TERTIARY STRATA OF THE PARIS BASIN. 



[Ch. II. 



points in the history of the discovery and classification of the 

 tertiary strata. 



Paris Basin. The first series of deposits belonging to this 

 class, of which the characters were accurately determined, were 

 those which occur in the neighbourhood of Paris, first described 

 by MM. Cuvier and Brongniart*. They were ascertained to 

 fill a depression in the chalk (as the beds d, in diagram No. 2, 

 rest upon c), and to be composed of different materials, some- 

 No. 2. 



a, Primary rocks. 



b, Older secondary formations, c, Chalk. 

 d, Tertiary formation. 



times including the remains of marine animals, and sometimes 

 of freshwater. By the aid of these fossils, several distinct alter- 

 nations of marine and freshwater formations were clearly shown 

 to lie superimposed upon each other, and various speculations 

 were hazarded respecting the manner in which the sea had 

 successively abandoned and regained possession of tracts which 

 had been occupied in the intervals by the waters of rivers or 

 lakes. In one of the subordinate members of this Parisian 

 series, a great number of scattered bones and skeletons of land 

 animals were found entombed, the species being perfectly dis- 

 similar from any known to exist, as indeed were those of almost 

 all the animals and plants of which any portions were discovered 

 in the associated deposits. 



We shall defer, to another part of this work, a more detailed 

 account of this interesting formation, and shall merely observe 

 in this place, that the investigation of the fossil contents of 

 these beds forms an era in the progress of the science. The 



* Environs de Paris, 1811. 



