SUBMARINE DEPOSITS. 277 
“There are off the coasts of North and South Carolina small rocky 
banks slightly raised above the general level of the sea bottom, consist- 
ing of a calcareous material, which are probably the continuation of the 
tertiary beds found inland along the adjoining shores. They are cov- 
ered by corals (Oculina), gorgonians, and other invertebrates, and afford 
better feeding-grounds for fishes than the sandy bottom. They are the 
fishing-banks of the inhabitants. Similar banks are found off Cape 
Fear, and, to judge from the nature of the corals and shells thrown up 
on the beaches near Cape Hatteras and Cape Lookout, others probably 
exist in their vicinity.” 
In the strength of the current of the Gulf Stream the bottom 
was washed nearly bare, and we found little animal life in the 
trough of the stream. The bottom was composed of a hard 
limestone, the edges of the sounding-cylinder coming up much 
defaced. Off Charleston the whole width of the Gulf Stream 
was swept clean. From Jupiter Inlet to the latitude of the 
northern Bahamas the bottom specimens resembled more the 
ooze of the Gulf of Mexico and the Caribbean, containing a 
proportionally larger percentage of pteropod remains than the 
ooze farther north, where the globigerine increased in number. 
The rapid changes in the character of the mud in proportion 
to the distance from shore and the depth are well shown in the 
nature of the deposits at different levels along the short, steep 
line which forms the northern slope of the Blake Plateau to 
the south of Cape Hatteras. There we pass quickly from the 
comparatively coarse shore mud to finer and finer ooze, which 
becomes an impalpable silt in the deeper water beyond one 
or two thousand fathoms, assuming at the same time a lighter 
color. The gradual decrease of color of the bottom deposits 
with an increase in depth is very evident in the soundings 
Chemical reactions show that these grains portion of this concretion by M. Klement, 
are phosphatic They are similar to see Bull. M. C. Z., XII. No. 2. 
the grains found in phosphatie nodules « Тһе ‘Challenger’ dredged on several 
dredged off the Cape of Good Поре and occasions, especially off the Cape of Good 
id identical in their physical Hope, eoneretionary masses like that 
properties with the phos- above described, but very much smaller. 
elsewhere, 
and chemi 
ns in cretaceous rocks. 
phatie gr: 
“The mar 1ese is infiltrated through 
the whole m of the concretion. The 
phosphatic grains are sometimes enclosed 
in the manganese. For an analysis of a 
Phosphatie nodules were always found 
in the deposits at less than 1,500 fath- 
oms, near continental shores, but never 
in the deeper deposits far removed. from 
land." 
