To this inconceivably slowly-growing deposit of inorganic material over the ocean floor there is added an overwhelmingly more rapid contribution of the remains of calcareous and siliceous planktonic and benthonic organisms, which tend to bury the slower accumulating material under a blanket of globigerina, pteropod, diatom or radiolarian ooze.
Thus red clay and radiolarian ooze are distinguished as abyssal deposits in contradistinction to the epilophic calcareous oozes.
If there were strong currents at the bottom of the ocean the uniform accumulation of the deposit of minute shells of globigerina and radiolarian ooze would be impossible, the rises and ridges would necessarily be swept clear of them, and the fact that this is not the case shows that from whatever cause the waters of the depths are set in motion, that motion must be of the most deliberate and gentlest kind.
In the northern portion of the square, north and east of Wharton deep, the red clay is replaced over a large tract by Radiolarian ooze.
The first thing is to purchase a small vial of cleaned shells from radiolarian ooze.