﻿xliv PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



boniferous species, M. Elie de Beaumont having found this assem- 

 blage of fossils in shales so intercalated with Jurassic schists 

 containing Belemnites (the strata containing the plants and the Be- 

 lemnites being parallel and conformable), as to lead him to infer 

 that they were all parts of one formation. The dark shales con- 

 taining Belemnites were recognized as a portion of certain adjacent 

 rocks, in which Ammonites and other fossils characteristic of the Ju- 

 rassic series abound. Other able geologists afterwards visited the spot, 

 and at the Meeting of the French Geologists at Chambery in 1841, 

 they confirmed the views previously announced by M. de Beaumont. 

 M. Favre, however, endeavoured to explain the anomaly by supposing 

 that true carboniferous schists, originally underlying liassic strata, 

 had been thrown together with them into a sharp anticlinal flexure, 

 portions of which had been subsequently denuded ; and he pointed 

 out that in another part of the Alps similar schists, containing coal 

 plants, constitute the conformable base of the liassic group*. Sir 

 Roderick Murchison visited Petit-Coeur in the course of his Alpine 

 excursions in 1847 and 1848, and gave a section showing that the 

 plant-bearing anthracitic schists can be traced within one foot of the 

 parallel dark shales containing Belemnites ; and, to cite his own words, 

 " the Belemnite and plant beds form parts of the same geological 

 mass, the upper and lower parts of which are of similar composition, 

 consisting of talcose schist and sandstone. In fact I cannot imagine 

 how any geologist can look at this section, and not declare that the 

 whole of these strata form a natural group of very small dimensions f." 

 He also affirms, " that if, by a modification of the flexure theoretically 

 suggested by M. Favre, we could get over the difficulty, the section 

 at Petit-Coeur would be more deceptive than any he has ever exa- 

 mined, and until more proofs are obtained to the contrary, he must 

 repeat his belief that the relations of the strata sustain the conclusions 

 of M. E. de Beaumont J." 



When we are to choose between two alternatives, a most extraor- 

 dinary displacement or contortion of stratified masses, or an exception 

 to the laws elsewhere found to prevail in the geological distribution 

 of organic remains, we must duly weigh, not only the singularity of 

 the required mechanical disturbance, but also the extent of the palse- 



* Bulletin Soc. Geol. de France, vol. v. p. 263. 



t Quart. Journ. Geol. Soc. vol. v. p. 177. % Ibid. vol. v. p. 179. 



