114 



SUPPOSED UNIVERSALITY 



[Ch. VI. 



those of Africa — in a word, in every quarter of tlie globe, were 

 referred to one and the same period. The burden of proof 



was 



not supposed to rest with those who insisted on the 

 identity in age of all these groups — their identity in mineral 

 composition was thought sufficient. It was in vain to urge 



as 



im 



imnlies that all the movm 



simultaneously charged with sediment of a red colour. 



But the rashness of pretending to identify, in age, all the 

 red sandstones and marls in question, has at length been 

 sufficiently exposed, by the discovery that, even " ~ 



many 



The inves- 



tigations of De Verneuil in Spain have shown that the red 



m 



Middle 



marls 



period. It is also known that certain red 

 gated sandstones in Auvergne which are undistinguishable in 

 i in Aral pomnnsition from the New Red Sandstone of English 



geologists, are nevertheless of the same older tertiary period : 



and, lastly, the gypseous red marl of Aix, in Provence, 

 formerly supposed to be a marine secondary group, is now 

 acknowledged to be a tertiary freshwater formation. In 

 Nova Scotia one great deposit of red marl, sandstone, and 

 gypsum, precisely resembling in mineral character the * New 

 Red ' of England, occurs as a member of the Carboniferous 

 group, and in the United States near the Falls of Niagara, a 

 similar formation constitutes a subdivision of the Upper 



Silurian series.* 



Nor was the nomenclature commonly adopted in geology 

 without its influence in perpetuating the erroneous doctrine 

 of universal formations. Such names, for example, as Chalk, 

 Green Sand, Oolite, Red Marl, Coal, and others, were given 

 to some of the principal fossiliferous groups in consequence 

 of mineral peculiarities which happened to characterise them 

 in the countries where they were first studied. When geolo- 

 gists had at length shown, by means of fossils and the order 

 of superposition, that other strata, entirely dissimilar in 

 colour, texture, and composition, were of contemporaneous 



* See Lycll's Travels in N. America, ch. 2. and 25. 







