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- 
and’s arrangement is designated by the name of green sand ; though 
the latter appellative has generally been reserved for a division of 
this formation.+ On the continent this series is called the ancient 
chalk (la craie ancienne), lower chalk (la craie inferieure), &c.— 
while particular beds of it are called, according to their mineralogical 
characters, sable ferrugineux, craie chloritée, craie tufau, ec.  Fi- 
nally, this formation appears to be embraced in the quader sandstein? 
and plener kalk of Werner. 
Extent and Localities. 
The ferruginous sand formation of the United States 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, &c.”t pelt Z 
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 
A ah ig ee eee a cal i ree ne oe ne 
*The papers by Mr. Vanuxem and myself will be found in the VI. Vol: Jour. 
i iladelphia. 
gycstertse oe rie the ferruginous sand of England as ape#: of 
these four subdivisions, counting from below upwards: 1. Iron sand; 2. Weald 
clay; 3. Green sand; 4. Chalk marle. Geol. p. 60, 120, &e. 
} Vide a paper by me in Jour. Acad. Nat. Sc. Vol. VI. p. 127. 
