TERTIARY STRATA. 127 
The applications and uses of shell mari as a fertilizer of the 
soil are well known ; but some caution is necessary in drawing 
inferences from the facts stated in the various agricultural papers 
that have been published in regard to its effects. It is essential 
to its usefulness, that the shells be in a state of decay, so as readily 
to fall to pieces, and mingle in the condition of a fine powder 
with the soil, and so far as their value as a fertilizing agent is con- 
cerned, it is unfortunate, that most of the shells of North Caro- 
lina belong to the Pliocene, rather than the Eocene, or Miocene 
eras. In many cases the original cohesion of their particles is 
scarcely impaired, and they are comparatively worthless. Cen- 
turies may elapse, before they shall be brought to resemble the 
older marls of the present day.* 
The comparative newness of the tertiary strata of North Caro- 
lina, the much greater proportion of recent or living species 
found in them, indicates, that an elevating force has been exerted 
beneath the eastern part of this state, at a later date than on any 
other part of the coast. Such Pliocene beds as are still reposing 
beneath the waters of the ocean, off the shores of the states north 
and south of us, have here, been raised above the surface, and are 
cultivated soil. The centre of the disturbance appears to have 
been somewhere amongst the lower waters of the Neuse and Tar. 
On looking at a map of the United States, it will be seen that 
North Carolina projects pretty far beyond the general range of 
the coast. The capes and shoals that render a voyage from New 
York to Charleston, so long and dangerous, may be regarded as 
one of the results of these later geological changes. 
When however the upheaving of the south-eastern counties, 
and their elevation above the waters of the ocean, are spoken of 
as recent events, it is to be understood that they are such, only 
in reference to other changes in the crust and surface of the earth. 
Since their occurrence, whole races of animals have perished and 
disappeared, and new ones been created to supply their places, 
some new species of vegetables have been called into being, and 
time enough has elapsed, to allow of the dissemination of others 
from their original seats, so uniformly, over the new contiguous 
surface, that no difference is discoverable between the old and new 
habitats, in regard to either the number, or the variety, of the in- 
dividuals that occupy the soil. The pines are as widely and as 
*To the Conchologist, the very circumstance which deprives them of value 
in the estimation of the farmer, gives them additional interest and beauty. 
The finest collection I ever saw, was one made by my friend and former pu- 
pil, Richard Evans, Esq., of Greenville, in Pitt County, whilst raising- marl 
from the bank of the Tar, to be applied to the soil, and of which I have not 
heard that any essential benefits were derived from it. Upon the students of 
the University who shall hereafter be settled in the region of these interesting 
remains, the duty may be earnestly enjoined of lending their aid to these in- 
vestigations. A box of shells carefully selected, well packed, and forwarded, 
will be a valuable contribution to the science of Geology. 
