Parallelism of the Palceozoic Deposits, fyc. 45 



Art. IV. 



Parallelism of the Palceozoic Formations of North 

 America, with those of Europe ; by Ed. de Verneuil. 



(Continued from pp. 183, and 370, vol. v.) 



Carboniferous System. — Of all the principal divisions of which 

 the palaeozoic formation in America is composed, the Carbonifer- 

 ous system is that which is best defined, and has the most char- 

 acters ia common with European deposits of the same age.* It 

 includes two or three stages, according as it is considered in the 

 eastern or western states of the Union. It commences below by 

 a micaceous psammite which so much resembles the rocks of the 

 Portage [Chemung] group, that they have been completely assim- 

 ilated. -f The geologists who have attempted to show the paral- 

 lelism of the American formations with those of Europe, have 

 thus referred to the Devonian system those sandstones so well 

 known in the states of Ohio and Indiana under the name of fine- 

 grained sandstone, or Waverly series. The examinations which 

 we have made to the south of Cleveland, in the state of Ohio, the 

 iossils which we have found near Medina. J Cuyahoga and New- 

 ark, Ohio, have convinced us that a great part of these sand- 

 stones belong really to the Carboniferous system. The lower 

 beds only may represent the Devonian stage of Portage, but as 

 the rocks of this group completely resemble those which we 

 unite with the Carboniferous system, and as in the state of Ohio 

 they do not contain fossils, it will be understood that it is almost 

 ^possible to distinguish, in the sandstones of Waverly, those 

 Which are the prolongation of the beds of Portage from those 

 which incontestibly belong to the Carboniferous system. § 



in the different parts of America through which we have travelled, we have 

 _ ayg readily distinguished it by its fossils, and have verified the truth of what 



e said seven years since, upon the importance of the limit which separates it from 



t W £ formatJons ' (Bull, de la Soc. Geo!., vol. xi, p. 166.) 

 Pr J G ^. rou S nt f rom Cuyahoga and from Medina, Ohio, psammites with 



° uctus, which it is almost impossible to distinguish mineralogicalJy from speci- 

 *en 8 ; found at the Falls of Portage, N. Y. 



{*! r .. are indebted to our colleague, Mr. W. C. Redfield.for directions in find- 

 ,n | r ^ ,! « at this locality. 



osit" a PP eHTS to us that here is an admission somewhat at variance with the prop- 

 WeH°H fl l lflecon,moncemcnl °^ the article. If the Carboniferous System is so 

 mn L ' e< * and characterized, there is no need of questioning the line of de- 



nation between the Portage and Chemung group, which are of admitted Pcvo- 

 an ■», and the Carboniferous sandstones. The truth, however, in, that there is 



no II ^arnoniferous sandstones. 1 tie irum, nowever, i*, mai mere i» 



well defined line of separation between the Chemung rocks of New York and 

 B sandstones of Obio and Indiana, which contain Carboniferous fossils. The 



ror of American geologists, who have attempted to compare our formations with 



ose of Europe, has been in this instance that of regarding the great carboniferous 



n »estone as forming the basis of that system, including all the strata below in De- 



° nian a nd Silurian. We have, in fact, been looking for great lithological chan- 



s£ s and topographical features at the limits between two great systems, but as 



*7 are now divided, these great features are more frequently observed in the 



dsl of a system than at its termination or commencement.— James Hall.} 



