322 W. B. CLARK — UPPER CRETACEOUS FORMATIONS OF NEW JERSEY. 



{Blue marl. 

 Ash marl. 

 Green marl. 

 Yellow sand. 



f Yellow limestone and lime-sand. 



Middlemari ^ j S"!S 



[ Chocolate marl. 



{Indurated green earth. 

 Red sand. 

 Dark micaceous clay. 



{Marl and clay. 

 Blue shell marl. 

 Sand marl. 



Clav marls I Laminated sands. 



J \ Clay containing greensand. 



{Lignite. 

 Potter's clay. 

 Lignite. 



In 1870 Dr Hermann Credner* above referred to, published the re- 

 sults of his observations upon the New Jersey Cretaceous. He regarded 

 the deposits as closely related to the upper Cretaceous of Europe, and 

 mentioned upward of 40 species of fossils as being identical with those 

 of the Senonian of northern Europe. 



In Jater years Professor R. P. Whitfield has been engaged in an ex- 

 haustive study of the fauna of the Cretaceous belt of New Jersey. Two 

 monographs of great importance have been published. The first, enti- 

 tled " The Brachiopoda and Lamellibranchiata of the Raritan Clays and 

 Greensand Marls of New Jersey," appeared in 1885, and the second, " The 

 Gasteropoda and Cephalopoda of the Raritan Clays and Greensand Marls 

 of New Jersey," in 1892. 



Dr C. A. White,f in an admirable essay upon " The Cretaceous of 

 North America,'^ published in 1891, describes the formations now under 

 consideration and discusses the evidence for their correlation with the 

 deposits of other areas. He does not attempt to separate the individual 

 members of the series, however, beyond the reference of the upper divis- 

 ion to the Eocene, as was also done by the senior author of this paper 

 in his report upon " The Eocene of the United States." J 



Investigations embracing portions of the Cretaceous series of the north- 

 ern Atlantic Coastal plain have been in progress at times during later 

 years by Uhler, § Darton,|| and Hollick-H Messrs Ilhler and Darton 

 have confined their investigations almost exclusively to the Cretaceous 



* Zeitf-chrift der Deutschen Geol. Gesell. Jahr., 1870, pp. 191-257, and map. 



f Bulletin 82 of the U. S. Geological Survey, 1891, p. 273. 



J Bulletin 83 of the U. S. Geological Survey, 1891, p. 173. 



§ Trans. Md. Acad. Sci., vol. 1, i889-'9o, pp. 10-32, 45-72, 97-105. 



|| Bulletin Geol. Soc. Amer., vol. 2, 1891, pp. 438, 439 ; Trans. Amer. Inst. Min. Eng., 1894. 



If Trans. New York Acad. Sci., 1895, pp. 1-10. 



