Sand Formation of the United States. 275 



same time compared these fossils with a series from the green sand* 

 of England, and was so struck with the resemblance as to draw a 

 conclusion which my subsequent investigations have confirmed. 



By most of the geologists of continental Europe, the green sand is 

 considered merely as a lower division of the chalk; while in Eng- 

 land it is supposed to be a link in a distinct formation, intermediate 

 between the chalk and the oolites. The facts and reasonings of Mr. 

 Alex. Brongniart seem to establish the correctness of the former 

 opinion. Be this as it may, I consider the marl of New Jersey as 

 referrible to the great ferruginous sand series, which in Prof. Buck- 

 land's arrangement is designated by the name oi green sand ; though 

 the latter appellative has generally been reserved for a division of 

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

 chalk (la craie ancienne), lower chalk (la craie inferieure), fee. — 

 while particular beds of it are called, according to their mineralogical 

 characters, sable ferrugineux, craie chloritee, craie tufau, ^c. Fi- 

 nally, this formation appears to be embraced in the quader sandstein"? 

 and planer kalk of Werner. 



' Extent and Localities. 



The ferruginous sand formation of the United ^tates contains a 

 considerable proportion of clay, often in beds ; hence if it were desir- 

 able to have a strictly descriptive name, (no common occurrence in 

 geology) we might call it ferruginous sand and clay. So far as it 

 has been explored, it already presents a considerable range. " It 

 occupies a great part of the triangular peninsula of New Jersey, 

 formed by the Atlantic, and the Delaware and Raritan rivers, and 

 extends across the state of Delaware from near Delaware city to the 

 Chesapeake : appears again near Annapolis, in Maryland ; at Lynch's 

 Creek, in South Carolina ; at Cockspur Island, in Georgia; and sev- 

 eral places in Alabama, Florida, &z;c."f 



In New Jersey, however, that tract which has been long known 

 as the marl district, may be more specifically located, as follows : — 

 Draw two lines, one from Amboy Bay to Trenton, the other from 



*The papers by Mr. Vanuxem and myself will be found in the VI. Vol. Jour. 

 Acad, of Nat. Sciences of Philadelphia. 



t Conybeare and Phillips describe the ferruginous sand of England as composed of 

 these four subdivisions, counting from below upwards: 1. Iron sand; 2. Weald 

 clay ; 3. Green sand; 4. Chalk marie. Geol. p. 60, 120, &c. 



t f^ule a paper by me in Jour. Acad. Nat. So, Vol. VI. p. 12T, 



