XII. 
SUBMARINE DEPOSITS. 
Тнк explorations of the “Blake” during my stay on board 
did not extend to oceanic basins far from land, but were limited 
to the investigation of enclosed seas like the Кы Ма and Gulf 
of Mexico, and of the continental edges of a part of the west- 
ern basin of the North Atlantic. The “Blake” subsequently 
sounded the oceanic basin to the west of the Bermudas and 
north of the Windward Islands. I have myself had no oppor- 
tunity of seeing on the spot the deposits characteristic of a true 
oceanic area, he have supplemented the results of the “ Blake ” 
by those obtained by the “ Challenger" and * Tuscarora" im 
the great oceanic basins. 
The character of the bottom specimens near shore differs very 
materially from that of deposits brought from corresponding 
depths in the open ocean. Along the Atlantie shores of the 
United States, these deposits are primarily affected by the geo- 
logical structure of the mainland, the width of the continental 
shelf, the direction of the currents and of the Jota: winds, 
and the presence or absence of rivers. Within the Caribbean 
and on the oceanic face of the Greater and Lesser Antilles, the 
presence of an equatorial current, of the tradewinds, of volcanic 
rocks, and of extensive limestone plateaux, introduces conditions 
Шу from those operating upon the Atlantic 
distance from shore 
In the í dco, although t 
basin is often very « conside: PE stil 
the char: 
| 
bottom де ров sits 18 alws ays somewhat affected 
vsical conditions. And nowhere in = Gulf 
1 
һу 1 its peculia1 
or the Caribbean, or around the Atlantic slope of the United 
States, do we find any ooze strictly comparable to that of th 
open oceanic basins. 
