128 GEOLOGY OF NORTH CAROLINA. 
densely distributed over the Pliocene formations of North Caro- 
lina, as over the secondary, or Eocene of South Carolina or Vir- 
ginia. The Elephant and Mammoth, and apparently no incon- 
siderable menageries of other animals, which either were pastured 
in the upper counties, and floated down the rivers after death, or 
more probably, lived and died, near where their bones were found, 
have disappeared, the one from the western continent, the other 
from the earth. 
Several teeth and other bones of the Mastodon or Mammoth 
were found 25 years since, during the excavation of the Clubfoot 
and Harlow canal, some of which are now in the cabinet of the 
University. We have also the grinder of an Elephant, found 
in the marl pits of the late Lucas Benners, Esq., 16 miles below 
Newbern, and other teeth not yet determined. The same pits 
afforded also, what were supposed by Mr. Croom to be fragments 
of the horns, hoof, and grinders, of a fossil elk. 
The only metallic substances that have been found within the 
limits of these deposits, are some of the ores of iron ; the bisul- 
phuret, hydrated oxide, and sulphate, or copperas. The first, occurs 
imbedded in a tenacious blue clay, and though well characterized 
when taken from the earth, is changed by exposure to the air, and 
converted by the absorption of oxygen, into the sulphate. In 
the bank of the Neuse at Waynesboro', is a mass of small branch- 
es of trees, that have been metallized by the substitution of this 
ore of iron, for the original woody fibre. Lignite, — wood that 
has been changed into coal, is common. 
62. The soil of the tertiary region is of very unequal fertility, un- 
known causes having produced an accumulation of sand on some 
points, and of clay, or of that mixture of sand, clay and lime- 
stone that forms good land, on others. The best body of land 
belonging properly to this formation, is undoubtedly on the north- 
ern side of the Albemarle Sound, — the incunabula gentis, orspot 
on which the first permanent settlements in North Carolina were 
made. What the relative ages are, of the belt of mixed charac- 
ter, having fixed rocks in the beds of the streams, and sand and clay 
or the high grounds, and of these strata, that are certainly ter- 
tiary ; whether they were produced by the same causes, or by 
different causes, we have no means of determining. 
Secondary Strata. A formation of a different character, and 
as is proved by the shells imbedded in it, of much greater age, 
contemporaneous with the marls of New-Jersey, and the creta- 
ceous system of Europe, underlies the tertiary, in the southern 
part of the state, and crops out at intervals, from the eastern part 
of Jones County, to the Cape Fear. It is well exhibited at. Wil- 
mington, with the shells of the tertiary reposing directly upon 
it. Where it presents itself at the surface, the soil is generally 
characterized by a much higher degree of fertility. The greater 
proportion of good land in Jones, depends upon the fact that this 
formation is largely developed there. The rich lands of Onslow, 
