. OF NEW JERSEY. 25 
tion of beds, and the introduction of entirely new forms of 
animal life more like those of modern times. The period 
during which this deposit, so near the present coast line, 
was formed, as also many corresponding deposits in other 
regions of the earth, is called in geology, the Tertiary. Its 
beginning was the “morning of the sixth day” of the Mo- 
- saic record of the Creation, This great period, after hav- 
ing seen many changes, culminated in the creation of 
man. At this point history begins, and no extended 
geologic changes have taken place since. We have ad- 
vanced six thousand years, or probably, considerably far- 
ther into the “seventh day” or period. 
The beds of green marl were laid down during the 
upper Cretaceous period. Ata suitable depth of water 
along the several ancient coasts, lived immense num- 
bers of minute marine creatures, called Foraminifera, 
which inhabited delicate, almost microscopic shells, com- 
posed of numerous cells. After their death the chamber 
of the cells became filled with the fine mud formed of 
dissolved clay, oxide of iron and other substances, which 
are enumerated by Prof. G. H. Cook, in his valuable Re- 
port on the Geology of New Jersey. When the beds . 
were raised, the drying, and other agencies brought to 
bear, decomposed the delicate shells, and left only the 
hardened mud as casts. of their chambers. Hence the 
green marl now. resembles gunpowder, deriving its pecu- ` 
liar color from the protoxide of iron. 
The valuable properties of this marl, as a manure, no 
doubt depend on the products of the decomposition of the 
vegetables and animals formerly dwelling in the ocean or 
on the neighboring shores. The numerous fossiliferous 
beds, one or more of which are usually cut across by the 
diggings, have supplied in part this material. Most of 
AMERICAN NAT. VOL. I. 4 
