244 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC. 13, 



tures laid down on maps in the manner in which L. von Buch, 

 Prof. Studer and M. Eseher de Linth are working them out, it will 

 be seen, that although their major axes have a strike from E.N.E. 

 to W.S.W., there are numberless local deviations, and sometimes to 

 a very considerable extent. In fact, it is in the very nature of the 

 formations which clasp round such ellipsoids as those before spoken 

 of, that they should present local aberrations from any one chief line. 

 Such divarications occur in the masses which surround the great 

 ellipsoid of the Grisons and the canton Glarus ; for although the major 

 axis of that tract proceeds from E.N.E. to W.S.W., the strata where 

 they conform in outline to the ends of the ellipse, depart considerably 

 from the normal direction. I examined this phsenomenon on the 

 north-eastern portion of the external zone of this great ellipsoid in 

 the company of M. Eseher, viz. in the environs of the lake of Wal- 

 lenstadt ; and as a map of this tract was coloured for me on the spot 

 by my companion, I have exhibited it to the Geological Society, to 

 illustrate the phsenomenon under consideration. To attempt to 

 describe this tract in words would be in vain, and I therefore content 

 myself with saying, that this map shows, that whilst the chief anti- 

 clinal and synclinal lines conform to the general axis of the chain, the 

 rock masses of various ages, from the Jurassic to the nummulitic rocks 

 and flysch inclusive (which in the chief ridge of Sentis and along its 

 outer face strike E.N.E.), are bent round to the S.E. and S. at the 

 east end of the lake of Wallenstadt and in the valley of the Rhine 

 near Sargans. In this short space the rocks, therefore, become 

 strikingly divergent from the major axis, or in other words, they fold 

 round the extremity of the ellipsoid. I must leave others to expa- 

 tiate on the phsenomenon, which will be the better understood when 

 M. Studer shall have developed all his views, and when it may be 

 ascertained, that the massive ellipsoids of Mont Blanc, the Finsteraar- 

 horn, the St. Gothard, La Selvretta, &c. have been acted upon by 

 subterranean forces peculiar to each, and yet all partaking of one 

 common line of direction. 



It is worthy of remark, that just as the metamorphism of the 

 rocks is greater as we approach the centre of the chain, so do the 

 sedimentary masses the more arrange themselves on the surface, as 

 if their external configuration were intimately connected with some 

 grand crystalline change. On the other hand, as we extend our 

 researches to the outer zones of the chain, we pass over numerous 

 folds and breaks, all of which are evidently referable to pure me- 

 chanical agency. Thus, on the N.W. face of the synclinal valley of 

 Wildhaus, we meet with the system of flexures in the Hoher Sentis 

 already alluded to (PI. VII.), whereby the neocomian, greensand and 

 chalk are repeated on lines trending due N.E. and S.W., and forming 

 the ridges and troughs of that remarkable group, slightly divergent 

 from parallelism to the true axis. In alluding to the synclinal troughs 

 which run parallel to the major axes of the Alps, it is to be observed, 

 that in one tract the same trough will be found unbroken, which 

 when followed in its direction, shows different degrees of rupture. 

 One of the troughs before alluded to in the promontory of Biirgen 

 (figs. 9 & 10, p. 1 92), on the west side of the Lake of the four cantons, 



