1836.] 



FARIMERS' REGISTER. 



205 



tlie tbrinatioii on the side of the ocean, and that 

 on the .siJe of the Mediterranean. 



It is found at an almost equal height in the en- 

 virons of Lausanne hi Switzerland, of Thonon in 

 Savoy where it rises above the alluvions of the 

 borders of the Lake of Geneva. The great ar- 

 gilo-silicious table land of the basin of the Rhone, 

 which from the gates of Lyons, covering a |)art of 

 tire departments of Ain and of Saone-et-Loire, 

 reaches to the middle of that of Jura, rests on el- 

 evated chaussees of the granites of * 



near Lyons: and what is very remarkable, is that, 

 as we have said elsewhere, the general declivity of 

 this plateau lies in a direction contrary to the 

 course of the rivers which border it; that it goes 

 on increasing in this direction for the 20 leagues of 

 its length, so that the plateau towards the heights 



of '- * ends by rising nearly 100 toises 



above the course of the rivers which bound it on 

 the two sides. 



VL The li-agments of rocks which this forma- 

 tion contains, are always pieces more or less 

 rounded by the movement of waters, and the 

 largest are generally found at the greatest depth. 

 The strata are always h.orizontal, the sand is al- 

 most always coarser in the inferior strata, and its 

 grains are successively finer up to the surface, where 

 they are very minute. All these circumstances 

 evidently indicate successive precipitations fiom a 

 liquid, in the bosom of which the suspended earthy 

 particles have been at liberty to obey the law 

 of their gravities. It is then an aqueous deposite 

 which has extended itself over vast surfaces. Nev- 

 ertheless, it is not to be believed that this deposite 

 has been lor a length of time carried along by the 

 waters before its precipitation, for it frequently con- 

 tains fi-agments whose angles s'ill remain and 

 which have not been rolled long enough to be- 

 come round. In the basin of the Seine the 

 flints of chalk beds, which are there met w^ith 

 with still preserve, in part, their native forms; and 

 the fragments of mill-stone (silex carie) w4iich 

 are found in Sologne are not yet rounded, although 

 they have been rolled; and finally the rolled flint- 

 stones which are found in the argilo-siliceous de- 

 posite of the Rhone belong to the ancient alluvions 

 of the basin, and have not received their form in 

 the various movements of the deposite in| which 

 they now occur. 



VI}. Every where'this stratum covers the great 

 formations and is no where covered by them; it is 

 then evidently the last of the great alluvions 'of 

 the last great revolution which has^ agitated__ the 

 surface oi" the globe. 



VIII. It'does not appear possible to attribute it to 

 fi'esh waters, to the formalions,always partial, of ri- 

 ver waters, which take a distinct character in each 

 basin, and generally occupy its bottom. We do not 

 find in it the fresh water remains so numerous in 

 marls, as well the stony, as the earthy kinds; 

 and, besides, when the basins of rivers are not 

 separated by mountains, this formation, occu- 



* These blanks occur in the French publication and 

 probably were made necessary by the illegibility of the 

 manuscript. In |the several pieces by M. Puvis, as 

 published, there are numerous indications of mistakes 

 of the author's words; and sometimes others of liis 

 meaning — so manifest, that the translator has ven- 

 tured to alter them. — Er. 



|)ies the whole extent of the intermediate ridges or 

 table lands. Finally, the alluvion placed in the 

 basin of the ocean rises on llie slopes of the moun- 

 tains to the same relative height as that placed in 

 I he basin of the Mediterranean; and where these 

 mountains are depressed, the strata of tins alluvion 

 unite, and are counlbunded. 



This stratum of identical composition which co- 

 vers such vast extents in countries distant from 

 each other, which has risen above the basin of 

 rivers, which unites the basins of seas, can, it seems 

 only be owing to the last phasis of the movement 

 of great waters, of the movement of seas them- 

 selves confounded together. 



It is true that few marine remains are met with 

 in this stratum: the lew i)etrified sea-urchins, which 

 are found in Salogne may there be contemporary 

 vvith the beds of mill-stones which crop out 

 through the argilo-silicious stratum, and the for- 

 mation of which rises far beyond that of the de- 

 posite by which it is covered. 



IX. This stratum must then have been depo- 

 sited by the water over the v/hole surface; and it 

 would not be difficult to explain how, while con- 

 tinuing to cover the ridges and table lands, it may 

 have disappeared from the bottoms of the basins 

 which it covered. When, by a course of which 

 we are ignorant, the level of the inferior waters 

 was lowered, currents were formed in the interior 

 of the basins of the rivers which terminated in the 

 great reservoirs; the waters quitted the highlands, 

 to collect together in the basins, their natural bed; 

 the waters of the elevated parts of the table lands, 

 to reach their respective basins acquired but little 

 rapidity in their courses of short extent, and only 

 carried ofl' more or less of the last deposite, which 

 was not altered in its composition. Eut it was not 

 the same in the bottom of the basins; there, rapid 

 currents of great length were established; and im- 

 pelled by the waters above, they swept off the 

 last deposite and mingled its elements with the de- 

 posites of the inferior strata. 



When the waters became less rapid, the frag- 

 ments which they carried along, were successive- 

 ly deposited, commencing with the heaviest; and 

 as the}' approached a state of repose, the minute 

 particles which the waters retained in suspension 

 were precipitated, and formed the upper stratum, 

 which has become the vegetable stratum [or 

 mould] of the lower part of the basins, and which 

 is composed of fragments of all the formations 

 carried off by the the waters, the latest as well as 

 the most ancient. 



X. This is the place to remark that the argilo-sili- 

 cious deposites which cover the plateaux, generally 

 increase in stiffness as they approach the sea; thus, 

 in the basin of the Loire, the sands of the Sologne 

 are lighter than the same kind of table lands of 

 La Sarthe; so also, in the basin of the Seine, the 

 table lands of the Gatinais, and of the forest of 

 Fontainebleau, are less stift' than the analogous 

 ones of Bernay, and of the forest of Larche in 

 Normandy. 



The causes which have brought about this state 

 of liangs may be conceived: the sandy parti- 

 cles must have been first deposited, and have 

 formed the alluvions of the more elevated parts 

 of the basins; the waters on retiring have left them 

 successively exposed, and the fine and clayey par- 

 ticles, remaining last in suspension, have been 

 progressively more numerous in the deposites as 



