338 On the Secondary and Tertiary Formations. 
islands, were never to be found by man, though eagerly sought 
after. : 
- At Wilmington is another interesting locality, where not only 
the tertiary marl corresponding to that at the natural well is 
found, but the secondary sandstones and conglomerates below it 
are well exposed on the banks of Cape Fear river. ‘The lower 
tertiary is wanting, and this marl bed, which is from two to 
three feet thick, is seen resting upon the sandstones, containing 
shells belonging ‘altogether to the upper secondary formation. 
Above the marl, and resting on it, the upper stratum observed is 
of sand and loam, contaifing a few layers of small white peb- 
bles. ‘Fhe marl is nearly as prolific in shells as the same forma- 
tion at the natural well. ~The species, however, are not the same, 
as will be seen from the appended catalogue, (p. 344.) More than 
fifty species were collected, of which eight are recent, and those 
in italics new. Comminuted shells and fine sand form the matl 
stratum, and these are either converted into a solid mass not easily 
broken, or remain unconsolidated. The sandstone beneath is in 
one place a compact siliceous mass, but a little way off it changes 
to a coarse pebbly rock, consisting of small, rounded quartz peb- 
bles of a dark color; and then again it becomes so calcareous that 
with proper eare it might be burned to tolerable lime. The peb- 
bly rock or conglomerate contains shells, and corals, and small 
have generally disappeared and left only the casts; these, though 
very abundant and perfect, render it extremely difficult to detel 
Gryphea, Ostrea, Anthophyllum, Nautilus, &e. 9 
‘The proximity of this locality to the wharves and the town of 
Wilmington, would render it easy for strangers to obtain speck 
mens thence. ‘The marl is not here esteemed as a manure, prob- 
A ah SE Pc hy ta eaten 
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