64 Charles Schuchert — Historical Geology, 1818-1918. 



ferruginous sand series, which in Prof. Buckland's 

 arrangement is designated by the name of green sand. 

 . . . On the continent this series is called the ancient 

 chalk . . . lower chalk, ' ' etc. Again, the marls of New 

 Jersey are "geologically equivalent to those beds which 

 in Europe are interposed between the white chalk and 

 the Oolites." This correlation is with the European 

 Lower Cretaceous, but we now know the marls to be of 

 Upper Cretaceous age. Although Eaton objected stren- 

 uously to Morton's correlation, we find M. Dufresnoy of 

 France saying, "Your limestone above green sand 

 reminds me verv much of the Maastricht beds," a correla- 

 tion which stands to this day (22, 94, 1832). In 1833 Mor- 

 ton announces that the Cretaceous is known all along the 

 Atlantic and Gulf border, and in the Mississippi valley. 

 "The same species of fossils are found throughout," and 

 none of them are known in the Tertiary. He now 

 arranges the strata of the former "Alluvial" as follows: 



Modern 



Alluvial. 



Diluvial. 



C Upper Tertiary (Upper Marine). 

 Tertiary J Middle Tertiary (London Clay). 

 l^Lower Tertiary (Plastic Clay). 



q -, j Calcareous Strata ( Cretaceous group, or Ferrugi- 



seconaary | Ferrugin01is Sand j nous Sand series (24,128). 



Western Cretaceous. — In 1841 and 1843 J. N. Nicollet 

 announced the discovery of Cretaceous in the Eocky 

 Mountain area. Of 20 species of fossils collected by 

 him, 4 were said to occur on the Atlantic border, and of 

 the 200 forms of the Atlantic slope only 1 was found in 

 Europe. Here we see pointed out a specific dissimilarity 

 between the continents, and a similarity between the 

 American areas of Cretaceous deposits (41, 181; 45, 153). 



The Cretaceous of the Eocky Mountains was clearly 

 developed by F. V. Hayden in 1855-1888 and by F. B. 

 Meek (1857-1876). Other workers in this field were 

 Charles A. White (1869-1891), and E. P. Whitfield (1877- 

 1889). Since 1891 T. W. Stanton has been actively inter- 

 preting its stratigraphy and faunas. 



Cretaceous and Comanche of Texas. — The broader 

 outlines of the Cretaceous of Texas had been described 

 by Ferdinand Eoemer in 1852 in his good work, Kreide- 



