374 Proceedings of the 



This is the chain, the linear direction of which would, if prolonged, 

 terminate near the mouth of the Bidassoa. The general summit of 

 the Pyrenees passes suddenly from the ridge, to another more 

 southerly, which is the principal, as it embraces in its almost parallel 

 linear direction the most remarkable points of the chain. It may 

 easily be seen that this ridge is not, as has been supposed by some 

 geologists, united with the preceding by means of a winding fold ; 

 and that the two ridges only join by their inverse declivities in the 

 basin of Beret, which, as well as the great basin of Cerdagna, was 

 formerly a lake, the waters of which must have flowed simultane- 

 ously towards France, and towards Spain. We, therefore, see that 

 the Pyrenean chain, simple as it is, is composed of several ridges, 

 having different directions, both in their masses and in their strata ; 

 which proves the error of M. Elie de Beaumont, in supposing the 

 Pyrenees to have been formed at a single ejection, by the application 

 of his own principle, that eminences having different directions are the 

 result of different evulsions. The Pyrenees contain numerous indi- 

 cations of rocks thrown up at various epochs. The most ancient of 

 these is the presence of dry storax in the grauwaken of Maladetta, 

 and in the deposits of anthracite of the intermediary formations. 

 The period at which these ancient formations were thrown up cannot 

 well be ascertained, but it is certain that when they were formed, the 

 plants, the remains of which are buried in them, crowned the heights 

 round their basins, which heights were already mountains. The only 

 spot in which the sedimentary tertiary formation, not alluvial, and 

 similar to that of the Herault, and the Apennines, is found in contact 

 with the Pyrenean rocks, is where the Est empties itself into the 

 plain ; for from the borders of the sea of Gascony to the mouth of 

 the Est, in the Mediterranean, the chain appears surrounded with 

 alluvial formations ; but at Nassaich, near Mill as, the sands of the 

 shelly deposit leave uncovered a large fragment of molanes, and of 

 bluish sandy marl fixed to the Pyrenean quartz-rock. This curious 

 fact is sufficient to destroy the hypothesis of the Pyrenees being 

 anterior to the Alps, and would even, perhaps, authorise a contrary 

 conclusion, as the glauconian deposits which, in the Pyrenees, occupy 

 the central point of Mont Perdu, are only met with in the Alps on the 

 eastern summits and at medium heights ; such as the mountain of 

 Fis, near Serrais, and that of Diableritz in the Lower Valais ; and 

 the molanes which, in the Pyrenees, rest immediately on the rocks 

 of the central ridge, in the Alps, do not attain that ridge at all, 

 but occupy only a part of the exterior chain, which, according 

 to Saussure, belongs rather to the system of the Jura, than to that of 

 the Alps of Mont Blanc. In conclusion, M. Nebaul remarks that 

 as the greater part of mountainous systems (except the volcanic ones) 

 have a great resemblance in the composition and the dispositions of 

 their rocks, it is probable that their differences arise much more from 

 the accidents of locality than from any general relations derived from 

 the period of the commencement or completion of their formation. 



