OCE chapter 4

core

(1) The deep, central layer of Earth, composed primarily of iron and nickel. It is subdivided into a liquid outer core 2270 kilometers (1410 miles) thick and a solid inner core with a radius of 1216 kilometers (756 miles). (2) A cylinder of sediment and/or rock material usually obtained by drilling.

Of the following, which energy resource(s) can be extracted from marine sediments?

-Gas hydrates -Petroleum

The sediments that are produced in areas of high primary productivity are indicated by the number(s):

2 & 3.

Calcareous oozes are represented by the number(s):

4

metal sulfide

A compound containing one or more metals and sulfur.

manganese nodule

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

manganese nodule/crust

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

spherule

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

oolite

A deposit formed of small spheres from 0.25 to 2 millimeters (0.01 to 0.08 inch) in diameter. Each oolite is composed of concentric layers of calcite.

gas hydrate

A lattice-like compound composed of water and natural gas (usually methane) formed in high-pressure and low-temperature environments such as those found in deep-ocean sediments. Also known as clathrates because of their cage-like chemical structure.

diatom

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

coccolithophore

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

petroleum

A naturally occurring liquid hydrocarbon.

ooze

A pelagic sediment containing at least 30% skeletal remains of pelagic organisms, the balance being clay minerals. Oozes are further defined by the chemical composition of the organic remains (siliceous or calcareous) and by their characteristic organisms (e.g., diatomaceous ooze, foraminifer ooze).

turbidite deposit

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

evaporate mineral

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

phosphorite

A sedimentary rock composed primarily of phosphate minerals.

meteorite

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

precipitate

A substance that is formed chemically whenever dissolved materials change from existing in the dissolved state to existing in the solid state.

sorting

A texture of sediments, where a well-sorted sediment is characterized by having great uniformity of grain sizes.

quartz

A very hard mineral composed of silica, SiO2.

Which of the following is the most dominant sediment in the deepest ocean basin - the North Pacific?

Abyssal clay

The proportion of sediment types in the Pacific Ocean, Indian Ocean, and Atlantic Ocean varies. Choose the statement that offers the best explanation for the differences in sediment abundance between the North Atlantic and North Pacific basins.

Abyssal clays are more abundant in the North Pacific than the North Atlantic because calcareous oozes dissolve before reaching the sea floor in the North Atlantic ocean basin.

salt deposit

An evaporative deposit composed of precipitated salts from seawater such as halite, gypsum, and in some cases calcite.

radiolarian (plural)

An order of planktonic and benthic protozoans that possess protective coverings usually made of silica. Also Radiolaria (singular)

foraminifer

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

Which type of marine sediments include siliceous and calcareous oozes?

Biogenous

Which type of sediment deposit has an average rate of deposition (per 1000 years) of 1 centimeter (0.4 inch)?

Biogenous ooze, pelagic deposit

Which type of marine sediments include space dust and meteors?

Cosmogenous

abyssal clay

Deep-ocean (oceanic) deposits containing less than 30% biogenous sediment. Often oxidized and red in color, thus commonly termed red clay.

Which of the following was used during early exploration of the oceans to collect sediment samples?

Dredge

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.

Shortly after the devastating 2011 Tohoku-Oki Earthquake, the Chikyu drillship began an expedition to study which of the following?

Earthquake-generated heat from friction

Which of the following is a hollow steel tube with a heavy weight on top that is to collect sediment samples?

Gravity corer

What does JOIDES stand for?

Joint Oceanographic Institutions for Deep Earth Sampling

Volcanic ash is considered to be which type of marine sediment?

Lithogenous

Which type of sediment deposit has an average rate of deposition (per 1000 years) of 0.001 millimeter (0.00004 inch)?

Manganese nodule, pelagic deposit

The ancient remains of which of the following, buried before they could decompose, are the source of today's petroleum deposits?

Microscopic organisms

neritic deposit

Neritic sediment - Sediment composed primarily of lithogenous particles and deposited relatively rapidly on the continental shelf, continental slope, and continental rise; neritic deposits are those that are produced from neritic sediment.

Which part of the ocean is considered to be the most climatically sensitive regions on Earth?

North Atlantic

pelagic deposit

Pelagic sediment - Sediment composed primarily of fine lithogenous and biogenous particles that is deposited slowly on the deep ocean floor; pelagic deposits are those that are produced from pelagic sediment.

Which of the following resources found in ocean sediments has the greatest economic value?

Petroleum

Which of the following sediments are biogenous?

Radiolarian, diatom, & calcareous ooze

Which of the following is the major environmental concern regarding the release of methane from the sea floor to the atmosphere?

Release of large quantities of methane from the ocean causes dramatic effects on global climate.

Which of the following is the most advanced technology used to collect sediment samples from the deep ocean?

Rotary corer

Which type of sampling did the JOIDES Resolution conduct?

Rotary drilling

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.

biogenous 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.

cosmogenous sediment

Sediment derived from outer space.

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.

tektite

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

The largest unexplored potential for metallic minerals in offshore sand deposits may exist along the west coast of ________.

South America

Ocean sediments consist of particles that have slowly settled out of the water by which of the following the processes?

Suspension settling

grain size

The average size of the grains of material in a sample. Also known as fragment or particle size.

Collecting adequate samples from which of the following is the most difficult?

The deep-ocean floor

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)

paleoceanography

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

test

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

clathrates are also called

These are also called gas hydrates.

What factor primarily determines the distribution of radiolarian ooze?

areas of upwelling

Much of the Pacific Ocean is deeper than the ______________________, so ___________________ dissolve before settling on the sea floor.

caclite compensation depth (CCD); calcareous oozes

Marine sediments that originate in the warm tropical surface ocean would create deposits in the deep sea composed primarily of ___________.

calcium carbonate

The sea floor provides the largest reservoir of usable energy in the ocean, and likely the world, in the form of ______________.

clathrates

Which sediment type dominates in the neritic environment?

coarse lithogenous sediment, such as sand and small rocks

Of the metals commonly found in manganese nodules, ________ is the only metal deemed "strategic" for the United States.

cobalt

What sediment type(s) is/are included in the pink category labeled "Other" on the map?

cosmogenous sediments hydrogenous sediments

Coarser lithogenous sediments tend to be

deposited on the continental margins.

A very important way to increase the settling rate of fine particles in the open ocean is via:

fecal pellets.

The main energy resources associated with marine sediments are petroleum and ________.

gas hydrates

In general, polar neritic sediment tends to have more ________.

gravel than in tropical waters

Gas hydrates composed of __________- are the most common.

methane

The type of marine sediment that forms the thickest deposits worldwide is:

neritic, lithogenous sediment deposits.

Sediments found on continental margins are called:

neritic.

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 ________.

paleoceanography

Calcium carbonate makes up the

protective cell wall of microorganisms that sink and form calcareous oozes.

Sediment samples from deep beneath the ocean floor are recovered by __________.

rotary drilling

Neritic sediments are most likely to be composed of __________.

sand, silt, and gravel

By analyzing cores of sediment collected from the sea floor, scientists can infer past environmental conditions on all of the following except ________.

sealife populations

The term referring to the size and shape of sediment particles is ________.

texture

Rotary drilling recovers core samples that are

too deep to reach by other means.

What factor primarily controls the distribution of calcareous ooze?

water depth

What mechanism(s) is/are responsible for transporting clay to deep ocean basins?

wind slow-moving ocean currents