IxXXvi PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Jura. The proof of contemporaneity of the phsenomena in these 

 different locaUties is necessarily imperfect from the circumstance that 

 the Gres de Fontainebleau does not extend beyond the Paris basin, 

 and no exact equivalent of it elsewhere has been determined. 



The next system, that of Sancerrois in the south of France, is re- 

 cognized also in Greece. Its epoch is supposed to be between the 

 end of the deposition of the Upper Freshwater Limestones of the 

 Paris basin, and the Faluns of Touraine. The system, however, does 

 not appear to be very determinate. 



The Alps are considered by M. de Beaumont to be the combined 

 result of several successive movements. The earliest of those of 

 which he there recognizes the influence, is that which produced the 

 system of Mont Viso during the Cretaceous period. He considers 

 the system of the Pyrenees, which elevated the Chalk and Num- 

 mulite formation, to be frequently traceable, in several portions of the 

 Alpine chain. Then came the system of Corsica and Sardinia and 

 that of the Isle of Wight, both anterior to the MoUasse, immediately 

 subsequent to the deposition of which came the movement which 

 produced our author's eighteenth system, that of the Western Alps. 

 Its epoch, therefore, corresponds to the completion of the middle 

 Tertiaries. The surrounding region then became occupied by exten- 

 sive lakes, in which was deposited the terrain de transport ancien, 

 at the period of the Upper Crag of this country, on the dislocated 

 beds of the Mollasse. This terrain de transport was in its turn 

 broken up by the great movement which gave its present form to the 

 principal chain of the Alps (extending eastward from the Vallais), and 

 produced the system which thence derives its name. Both these 

 Alpine systems are of wide geographical extent, and the latter 

 especially comprises some of the greatest dislocations to which south- 

 ern Europe has been subjected. It extends also, according to our 

 author, into northern Africa. In this country we have no traces of 

 either of them sufficiently determinate to demand particular notice. 



The latest system recognized by M. de Beaumont is the Sxjstem of 

 Tenarium, Etna, and Vesuvius. It is founded principally on obser- 

 vations in Greece, but comprises the volcanos of Etna and Vesuvius, 

 through which its great circle of reference is assumed to pass, in a 

 direction a few degrees W. of N. and E. of S. It is by means of 

 this hue that our author has fixed the position of his pentagonal re- 

 seau, one great circle of which (DH) has been assumed to coincide 

 with it. 



The systems of which I have given this brief sketch are those 

 which M. de Beaumont most distinctly recognizes in Europe, but 

 they are not restricted, according to his views, to this quarter of the 

 globe. He traces several of them into Asia, Africa, and America. I 

 shall not, however, attempt to follow him into these distant regions, for 

 my object has been to bring before you a part of the evidence on which 

 the truth of his theory rests, and it is manifest that such evidence 

 can only be sought in those regions with the geological structure 

 of which we are best acquainted. When we shall be satisfied of the 

 truth of the theory in its application to Western Europe alone, it 



