Radiolarian Ooze

a variety of present-day abyssal siliceous-argillaceous oceanic oozes that contains skeletons of radiolarians—planktonic protozoans. Moist radiolarian ooze is a brown (less often greenish gray or black) aleuritic-pelitic and pelitic sediment. It consists of the opaline silica SiO₂·nH₂O (5–30 percent), clay minerals, volcanic material, hydroxides of iron and manganese, and, sometimes, zeolites. Radiolarian ooze is found exclusively in the equatorial zone of the Indian and Pacific oceans at depths of 4,500 to 6,000 m (and greater). It covers about 3.4 percent of the floor of the world ocean. In a fossil state, radiolarian ooze turns into an organic sedimentary rock known as radiolarite.