134 ON THE HEVOLUTIOJrS DF 



all that of my friend, from the infinite pains he has bestowed from the 

 commencement of our plan, and, since our journies, on the profound 

 investigation of the objects, and in classifying the whole. I have, by 

 consent of M. Brongniart, placed it in the second part of my Researches, 

 in that in which I have treated of the fossil remains of our neighbour- 

 hood. Although relating, apparently, to a limited country, it affords 

 numerous results applicable to geology generall)'', and in this light may 

 be considered as an integral part of the present Discourse, ?t the same 

 time that it is most assuredly one of the finest ornaments of my work *. 



We have there the history of the most recent changes that have 

 taken place in a particular basin, and it leads us to the chalk forma- 

 tion, "whose extent over the globe is infinitely greater than that of the 

 materials of the basin of Paris. The chalk, which has been considered 

 as modern, is thus found to have a remote origin in the ages which 

 preceded the last catastrophe. It forms a kind of boundary between 

 the most recent formations, those to which the name of Tertiary may 

 be applied; and the formations which are called Sec onc^ary, those 

 which v\^ere deposited before the chalk, but after the primitive forma- 

 tions, and those termed Transition. 



The recent observations of many geologists who have followed up 

 our views, such as MM. Buckland, Webster, Constant-Prevost, and 

 those of M. Brongniart himself, have proved that these formations, 

 posterior to the chalk, have been reproduced in many other basins be- 

 sides that of Paris, although with some variations ; so that it has been 

 possible to constitute an order of succession, many of the stages of 

 which extend to nearly all countries that have been examined. 



Recapitulation of the Observations on the Succession of Formations. 



The most superficial strata, those deposites of mud and clayey sand 

 mixed with round flints transported from distant countries, and filled 

 ■with fossil remains of land animals for the most part unknown, or at 

 least foreign to the country, seem principally to have covered all the 

 plains, filled the bottoms of all caverns, choked up all the clefts of 

 rocks which have been in their way. Described with great care by 

 M. Buckland, under the name of diluvium, and very different from 

 other beds consisting of matter deposited incessantly by torrents and 

 rivers, which contain only^ relics of the animals of the country, and 

 which M. Buckland distinguishes by the name of alluvium; they form 



* Separate copies have been printed, entitled " Description Geologique des Envi- 

 rons de Paris," par MM. G. Cuvier and Al. Brongniart, second edition, Paris, 1822, 

 in 4to. 



