Ooze, a term technically applied to some kinds of deposits found covering the bottom of the deeper parts of the sea. It is not only the depth of the water, but the distance from the land which determines the occurrence of ooze. As we pass from the shore out to sea we find a succession of deposits, shingle, sandy mud, mud—all derived from the land; but at a distance varying from 60 to 300 nautical miles from the shore, and at a depth of 2000 feet or more, lie the various oozes, which consist of the remains of numerous small organisms, but especially of the shells of Foraminifera. A whitish deposit, containing enormous numbers of Globigerina shells, which in dying have sunk from the surface, is very widely distributed till depths of about 2000 fathoms are approached. There the Globigerina ooze wanes away, and is replaced in the deeper regions by so-called 'red clay.' At the surface above there are of course here as elsewhere abundant Foraminifera which still doubtless sink, but the physical conditions of the great depths are such that their shells are dissolved in falling. But in certain of the deepest parts—e.g. at 4575 fathoms—the Challenger explorers found another kind of ooze, composed of the flint shells of Radiolarians. Besides this, in other regions the shells of Pteropods and Diatoms are abundant enough to form a characteristic ooze.
It is to be understood, however, that the various oozes (Globigerina, Radiolarian, Pteropod, Diatom, &c.) pass into one another, and that the names usually express simply the predominance of one or other kind of shell, and also that the colours—white, yellow, brown, and red—mainly denote the proportion in which the 'red clay' is present. The latter owes its colour to the oxides of iron and manganese, and is composed of disintegrated materials of volcanic origin, such as pumice, and also of meteoric dust. These, after being carried by winds and floated on ocean currents, sink and are distributed at the bottom. But as to the ooze in the strict sense, it ought also to be noted that the dead or dying organic material, which the rain of these organisms brings to the bottom, serves as the fundamental food-supply of deep-sea animals, while the shells not only accumulate as ooze, but aid in the elevation of submarine volcano tops to the level at which corals can grow. Finally, the results of the ooze of incalculably distant ages are seen in the chalk cliffs often obviously composed of Foraminifera, or in such Radiolarian deposits as Barbados Earth. See CHALK, DIATOM, FORAMINIFERA, GLOBIGERINA, PTEROPOD, RADIOLARIAN, SEA, and the concluding volume of the Challenger Reports by Murray and Renard.