Siliceous ooze

A centric diatom, magnified x150

Siliceous ooze is a type of biogenic pelagic sediment located on the deep ocean floor. Siliceous oozes are the least common of the deep sea sediments, and make up approximately 15% of the ocean floor.[1] Oozes are defined as sediments which contain at least 30% skeletal remains of pelagic microorganisms.[2] Siliceous oozes are largely composed of the silica based skeletons of microscopic marine organisms such as diatoms and radiolarians. Other components of siliceous oozes near continental margins may include terrestrially derived silica particles and sponge spicules. Siliceous oozes are composed of skeletons made from opal silica SiO2·nH2O, as opposed to calcareous oozes, which are made from skeletons of calcium carbonate (CaCO3·nH2O) organisms (i.e. coccolithophores). Silica (Si) is a bioessential element and is efficiently recycled in the marine environment through the silica cycle.[3] Distance from land masses, water depth and ocean fertility are all factors that affect the opal silica content in seawater and the presence of siliceous oozes.

A radiolarian, 160x magnified
  1. ^ Mulder, Thierry; Hüneke, Heiko; Van Loon, A.J. (2011), "Progress in Deep-Sea Sedimentology", Deep-Sea Sediments, Elsevier, pp. 1–24, doi:10.1016/b978-0-444-53000-4.00001-9, ISBN 9780444530004
  2. ^ Bohrmann, Gerhard; Abelmann, Andrea; Gersonde, Rainer; Hubberten, Hans; Kuhn, Gerhard (1994). "Pure siliceous ooze, a diagenetic environment for early chert formation". Geology. 22 (3): 207. Bibcode:1994Geo....22..207B. doi:10.1130/0091-7613(1994)022<0207:psoade>2.3.co;2.
  3. ^ DeMaster, David J. (October 1981). "The supply and accumulation of silica in the marine environment". Geochimica et Cosmochimica Acta. 45 (10): 1715–1732. Bibcode:1981GeCoA..45.1715D. doi:10.1016/0016-7037(81)90006-5.