Oceanography Chapter 4

Front 1

Abyssal Clay

Back 1

Deep-ocean deposits containing less than 30% biogenous sediment, often oxidized and red in color, thus commonly termed “red clay”

Front 2

Algae

Back 2

Primarily eukaryotic, photosynthetic organisms, ranging in size from microscopic single cells to large organisms like giant kelp, also contribute to biogenous sediment

Front 3

Aragonite

Back 3

A carbonate mineral in marine sediment, has a different crystalline structure that is less stable and changes into calcite over time

Front 4

Biogenous Sediment

Back 4

Derived from the remains of hard parts of once-living organisms

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Calcareous Ooze

Back 5

Deposits comprised primarily of tests of foraminifers, coccoliths, and other calcareous-secreting organisms.

Front 6

Calcite

Back 6

Mineral formed from calcium carbonate (CaCO3)

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Calcium Compensation Depth (CCD)

Back 7

Located below the lysocline, 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.

Front 8

Calcium Carbonate (CaCO3)

Back 8

One of the most common chemical compounds in biogenous sediment, forms the mineral calcite

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Chalk

Back 9

A soft, compact form of calcite, generally gray-white or yellow-white in color and derived chiefly from microscopic fossils

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Coccolith

Back 10

Tiny calcareous discs averaging about 3 micrometers (0.00012 in) in diameter that form the cell wall of coccolithophores

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Coccolithophore

Back 11

A microscopic planktonic form of algae encased by a covering composed of calcareous discs

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Core

Back 12

A cylinder of sediment and/or rock material usually obtained by drilling

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Cosmogenous Sediment

Back 13

Derived from extraterrestrial sources

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Crusts

Back 14

A hard covering or surface layer of hydrogenous sediment

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Diatom

Back 15

A member of the class Bacillariophyceae of algae that possesses a wall of overlapping silica valves

Front 16

Diatomaceous Earth

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A deposit composed primarily of the tests of diatoms mixed with clay

Front 17

Evaporite Mineral

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A sedimentary deposit that is left behind when water evaporates, includes gypsum, calcite, and halite

Front 18

Foraminifers

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

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Gas Hydrates

Back 19

Unusually compact chemical structures made of water and natural gas

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Glacial Deposits

Back 20

A sedimentary deposit formed by a glacier and characterized by poor sorting

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Hydrogenous Sediment

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Derived from the dissolved material in water

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Ice Rafting

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Rock particles trapped in glacial ice are carried out to sea by icebergs that break away from coastal glaciers, as the icebergs melt, lithogenous particles of many sizes are released and settle onto the ocean floor

Front 23

Limestone

Back 23

Rocks from the marine environment composed primarily of calcium carbonate

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Lithogenous Sediment

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Derived from preexisting rock material that originates on the continents or islands from erosion, volcanic eruptions, or blow dust

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Lysocline

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The depth in the ocean at which the pressure is high enough and the amount of carbon dioxide in deep-ocean waters is great enough to begin dissolving calcium carbonate

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Macroscopic Biogenous Sediment

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

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Manganese Nodules

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Rounded, hard lumps of manganese, iron, and other metals typically 5 cm (2 in) in diameter up to a maximum of about 20 cm (8 in)

Front 28

Metal Sulfides

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Deposits associated with hydrothermal vents and black smokers along the mid-ocean ridge, contain iron, nickel, copper, zinc, and silver

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Meteorite

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A stony or metallic mass of matter that has fallen to Earth’s surface from outer space

Front 30

Methane Hydrates

Back 30

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

Front 31

Microscopic Biogenous Sediment

Back 31

A type of biogenous sediment which contains particles so small they can only be seen well through a microscope

Front 32

Nannoplankton

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Plankton less than 50 micrometers (0.002 in) in length that cannot be captured in a plankton net and must be removed from the water by centrifuge or special microfilters

Front 33

Neritic Deposit

Back 33

Deposits found on continental shelves and in shallow water near islands, generally coarse grained

Front 34

Oolite

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Small calcite spheres 2 mm (0.08 in) or less in diameter that have layers like an onion and form in some shallow tropical waters where concentrations of CaCO3 are high

Front 35

Ooze

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A pelagic sediment containing at least 30% skeletal remains of pelagic organisms, the balance being clay minerals

Front 36

Paleoceanography

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The study of how the ocean, atmosphere, and land have interacted to prudce changes in ocean chemistry, circulation, biology, and climate

Front 37

Pelagic Deposit

Back 37

Deposits found in the deep-ocean basins that are typically fine grained

Front 38

Phosphate

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Phosphorous-bearing compounds that occur abundantly as coatings on rocks and as nodules on the continental shelf and on banks at depths shallower than 1000 m (3300 ft)

Front 39

Phosphorite

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A sedimentary rock consisting of various phosphate minerals containing the element phosphorous

Front 40

Protozoan

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Any of a large group of single-celled, eukaryotic, usually microscopic organisms that are generally not photosynthetic, contributes to biogenous sediment

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Quartz

Back 41

Composed of silicon and oxygen in the form of SiO2, one of the most abundant, chemically stable, and durable minerals in Earth’s crust

Front 42

Radiolarians

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

Front 43

Rotary Drilling

Back 43

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 on the inside of the pipe

Front 44

Sediment

Back 44

Particles of organic or inorganic origin that accumulate in loose forms

Front 45

Siliceous Ooze

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The accumulation of siliceous tests of diatoms, radiolarians, and other silica-secreting organisms

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Sorting

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A measure of the uniformity of grain sizes and indicates the selectivity of the transportation process

Front 47

Spherules

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A cosmogenous microscopic globular mass composed of silicate rock material or of iron and nickel

Front 48

Stromatotlite

Back 48

Lobate structures consisting of fine layers of carbonate that form in specific war, shallow-water environments

Front 49

Tests

Back 49

Tiny shells produced by microscopic organisms that begin to sink after the organisms die and continually rain down in great numbers onto the ocean floor

Front 50

Turbidite Deposits

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A sediment rock formed from sediment deposited by turbidity currents characterized by both horizontally and vertically graded bedding

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Upwelling

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Deep-ocean water comes to the surface and supplies nutrients that stimulates high rates of biological productivity

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Wentworth Scale of Grain Size

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Indicates that particles can be classified as boulders, cobbles, pebbles, granules, sand, silt, or clay