12 
GEOLOGY OF NORTH CAROLINA. 
conditions being somewhat similar to those existing near the coast, the 
topography may be supposed to have been affected to some extent by the 
rotation. 
The State of Nebraska presents conditions quite similar to those of 
eastern North Carolina, its surface being a very gentle^slope of probably 
not more than a few feet to the mile, and its superficial geology being quite 
similar also, the whole area being occupied by the loess, or Quaternary 
sands, such as one sees on the upper Missouri every where. And in a 
recent description of the State in the New York Tribune , the fact is 
mentioned that the tributaries of its streams are all on the north side. 
And the same conditions are said to obtain in the plains of Siberia. 
Springs , Natural Wells and Ponds. — The rocks of this State, so far 
as their structure and stratigraphy affect the drainage and subterraneous 
circulation of meteroric waters may, for the most part, -be briefly de- 
scribed as stratified or foliated 8lates, schists and gneisses, which are in- 
clined to the horizon generally at high angles, so that the rain waters 
readily penetrate to great depths and issue at the base of the hills and 
mountains in numerous and perennial springs. 
A different state of things, however, obtains in the eastern section, 
where the strata belong, as just described, to the newer system of un- 
compacted and nearly horizontal strata. These accumulations, being gen- 
erally permeable to water, may give rise to springs wherever they hap- 
pen to be intersected by valleys or ravines. In the south-eastern section 
of the State, however, in the region between the lower waters of the 
Neuse and Cape Fear, these superficial and permeable rocks are under- 
laid by a harder stratum of limestone, which is sometimes a compact 
shell rock, as about Newbern and along Trent river ; sometimes a coarse, 
friable chalk, as on North-East river, in Duplin, and upper Trent, in 
.Tones, &c. ; and again a hard semi-crystalline limestone, as about Rich- 
lands, in Onslow; at Rocky Point, New Hanover; and a few miles above 
Wilmington, on the North-East river. It is this stratum which controls 
the subterraneous circulation of the region, being penetrated only at a 
few points where its substance has been dissolved and carried away by 
the percolation of carbonated waters, so that the overlying clays or sands 
have fallen through, giving rise to the phenomena of natural wells, as 
the noted one near Magnolia, in Duplin, and to the Crane Ponds in 
Onslow, which are only larger natural wells, and also to frequent sound- 
ing subterranean cavities, as in Jones county, into which sometimes cattle 
disappear by breaking through the thin covering of superficial earth or ' 
sand. This peculiar structure also gives rise to bold springs like those in 
Onslow called the “Alum Springs,” which issue from beneath the limestone 
