Iviii PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



beds containing coal-plants with semi-crystalline schists on the one 

 hand, and their association on the other with beds, containing Ammo- 

 nites and Belemnites of supposed Jurassic age have called forth the 

 ingenuity of the most able foreign and English geologists in their en- 

 deavours to explain a conjunction which appears to be in opposition 

 to the received principles of the science. To the discussion of this diffi- 

 cult question no less than sixty-eight memoirs have been devoted, in- 

 cluding the Addresses of Lyell and of Hamilton, and the papers of 

 Murchison ; and the recent discussion of them by M. Albert Gaudry 

 has fully exhibited the varieties of opinion and reduced them to some- 

 thing like order. Some, for example, have considered the alternation of 

 the anthracitic and liassic beds as the result merely of a folding of the 

 strata, the result of physical disturbance ; others have considered the 

 zoological characteristic of less value than the botanical, and therefore 

 placed all the beds in the Carboniferous series ; others again have 

 viewed the zoological of more importance than the botanical, and 

 allotted the whole to the Jurassic ; — in one case, therefore, assuming 

 that the Belemnites and Ammonites may have commenced their exist- 

 ence in the Coal-period, and in the other, that the Carboniferous 

 plants may have extended theirs into the Jurassic ; whilst M. Fournet 

 suggests that below the true Jurassic beds there may have been a 

 Triassic zone, or, as it were, a neutral ground between the two for- 

 mations. 



This brief notice of a discussion, which even now has not arrived 

 at a definite result, is sufficient to show how obscure a region which 

 has been the scene of so many great physical disturbances must 

 necessarily be, and to prepare us to expect many difficulties in the 

 consideration of its stratification. For a long time indeed it had 

 been admitted by most observers, that the secondary rocks of the 

 Alps were in many places overlaid by the crystalline schists which 

 formed the sides of the great central granitic axis ; and some there- 

 fore boldly recognized in such schists metamorphic rocks of the 

 carboniferous epoch, and other rocks of the cretaceous epoch, accord- 

 ing to the view respectively taken of the geological position of the 

 secondary rocks. Mr. Sharpe, however, viewing the rocks of the 

 Alps under a different aspect, consequent on the application of his 

 theory of cleavage, denied that the planes which separated the 

 mass of the crystalline rocks into apparent beds were anything more 

 than planes of cleavage, and consequently that the superposition was 

 not like that of strata deposited one over the other, or a super- 

 position of bedding, but simply apparent ; and in so far as this, Mr. 

 Sharpe only exercised a legitimate right in applying his own theory 

 towards the exemplification of facts ; but he was not equally justified 

 when he maintained that other authors had been deceived as to the 

 facts themselves, and asserted that M. Favre had nowhere seen the 

 crystalline schists of Mont Blanc lying upon the sedimentary beds in 

 the manner represented in the section which accompanied his paper. 



This subject was brought forward again during the Session by Major 

 S. Charters, in a paper on a section of Mont Lacha, near Mont Blanc, 

 where he states the dip of the strata to be to the north, at an angle 



