OCE 1001 Chapter 4

metal sulfides

A compound containing one or more metals and sulfur.

Manganese nodules

A concretionary lump containing oxides of manganese, iron, copper, cobalt, and nickel found scattered over the ocean floor.

Siliceous

A condition of containing abundant silica (SiO2).

Spherule

A cosmogenous microscopic globular mass composed of silicate rock material (tektites) or of iron and nickel.

Coccolithophore

A microscopic planktonic form of algae encased by a covering composed of calcareous discs (coccoliths).

Protozoa

A phylum of one-celled animals with nuclear material confined within a nuclear sheath.

Evaporite

A sedimentary deposit that is left behind when water evaporates; also known as evaporite minerals, which include gypsum, calcite, and halite.

Methane hydrate

A white compact icy solid made of water and methane. The most common type of gas hydrate.

Radiolaria

An order of planktonic and benthic protozoans that possess protective coverings usually made of silica.

Foraminifer

An order of planktonic and benthic protozoans that possess protective coverings, usually composed of calcium carbonate.

Calcite

CaCO3

DSDP

Deep Sea Drilling Project

Abyssal Clay

Deep-ocean (oceanic) deposits containing less than 30% biogenous sediment. Often oxidized and red in color, thus commonly termed red clay; composed of at least 70% (by weight) fine, clay-sized particles from the continents.

Rotary drilling

Drilling involving the use of a long, hollow pipe with a drill bit on its end that is rotated to crush the rock around the outside and retain a cylinder of rock (a core sample) on the inside of the pipe.

JOIDES

Joint Oceanographic Institutions for Deep Earth Sampling

Diatom

Microscopic, single celled, photosynthetic micro-organisms; because they photosynthesize, they are only found in the sunlit, shallow water.

Stromatolites

Oldest known fossils formed from many layers of bacteria and sediment.

Siliceous ooze

Ooze composed mostly of the T accumulation of siliceous tests of diatoms, radiolarians, and other silica-secreting organisms; When marine diatoms die, their tests rain down and accumulate on the sea floor as siliceous ooze. Hardened deposits of siliceous ooze, called diatomaceous earth

Benthic

Pertaining to the ocean bottom.

Cyanobacteria

Photosynthetic, oxygen-producing bacteria (formerly known as blue-green algae).

Glacial deposits

Poorly sorted deposits containing particles ranging from boulders to clays may be found in the high-latitude2 portions of the continental shelf.

Diatomaceous earth

Powder made up of ground shells of diatoms; lithified diatom-rich ooze

Lithogenous Sediment

Sediment composed of mineral grains derived from the weathering of rock material and transported to the ocean by various mechanisms of transport, including running water, gravity, the movement of ice, and wind. Sometimes referred to as terrigenous sediment.

Biogenius sediment

Sediment containing material produced by plants or animals, such as coral reefs, shell fragments, and housings of diatoms, radiolarians, foraminifers, and coccolithophores; components can be either macroscopic or microscopic; The distribution of biogenous sediment on the ocean floor depends on three fundamental processes: (1) productivity, (2) destruction, and (3) dilution.

Cosmogenous sediment

Sediment derived from outer space. May be found on earth in the from of microscopic spherules, microscopic meteor debris, or macroscopic meteor debris.

Hydrogenous sediment

Sediment that forms from precipitation from ocean water or ion exchange between existing sediment and ocean water. Examples are manganese nodules, metal sulfides, and evaporites.

Calcite Compensation Depth (CCD)

The depth at which the amount of calcite CaCO3 produced by the organisms in the overlying water column is equal to the amount of calcite the water column can dissolve. No calcite deposition occurs below this depth, which, in most parts of the ocean, is at a depth of 4500 meters (15,000 feet); It may be as deep as 6000 meters (20,000 feet) in portions of the Atlantic Ocean or as shallow as 3500 meters (11,500 feet)

Paleoceanography

The study of how the ocean, atmosphere, and land have interacted in the past to produce changes in ocean chemistry, circulation, biology, and climate is called

Test

The supporting skeleton or shell (usually microscopic) of many invertebrates.

Gravity corer

a device with an open tube that is dropped to the sea floor, allowing its weight to puncture the sediment

Sorting

a measure of the uniformity of grain sizes and indicates the selectivity of the transportation process.

Protozoan

are any of a large group of single-celled, eukaryotic, usually microscopic organisms that are generally not photosynthetic.

Lysocline

depth at which a significant amount of CaCO3 begins to dissolve rapidly;averages about 4000 meters (13,100 feet).

Pelagic deposits

found in deep-ocean basins and are typically fine grained; cover 3/4 of the ocean floor

Plankton

free-floating photosynthetic autotrophs that live in freshwater or marine ecosystems

diarrhea

frequent passage of loose, watery stools

Destruction (biogenous sediment distribution)

occurs when skeletal remains (tests) dissolve in seawater at depth.

Dilution (biogenous sediment distribution)

occurs when the deposition of other sediments decreases the percentage of the biogenous sediment found in marine deposits.

Neritic deposits

sediment found on continental shelves and in shallow water near islands, generally coarse grained; cover 1/4 of the ocean floor

Microscopic biogenous sediment

sediment that contains particles so small they can be seen well only through a microscope.

Macroscopic biogenous sediment

sediment that is large enough to be seen without the aid of a microscope and includes shells, bones, and teeth of large organisms.

Tests

shells and skeletons of microscopic organisms

Coccolithophores

single celled, photosynthesizing algae which are usually planktonic; 20-30 protective plate coverings (tests) made of calcium carbonate

Productivity (biogenous sediment distribution)

the number of organisms present in the surface water above the ocean floor.

Suspension settling

the process by which fine grained material that is being suspended in the water column slowly accumulates on the sea floor

Ice rafting

the process by which polar ice floats to sea carrying sediments that sink when the ice melts

Calcareous ooze

thick, common biogenous sediment produced by dissolving calcium carbonate shells

Lithified

turned into rock