Oceanography Ch. 4

The major force bringing continental sediments to the open ocean is (are)
(a) glaciers
(b) neritic currents
(c) rivers
(d) turbidity currents
(e) wind

e. wind

Which of the following is not an important control on oceanic sediment accumulation?
(a) degree of preservation
(b) dilution
(c) input from other sediments
(d) rate of deposition
(e) all of the above factors are important

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High energy environments are most likely to contain which one of the following?
(a) clay-sized particles
(b) cosmogenous sediments
(c) large particles such as gravel
(d) manganese nodules
(e) silt-sized particle

c. large particles such as gravel

Texture refers to the size and shape of sediment particles.
(a) True
(b) False

a. true

Sediments which are poorly sorted and made of a variety of minerals could have been deposited by
__________.
(a) a glacier
(b) a river delta
(c) turbidity currents
(d) a volcanic eruption
(e) the wind

c. turbidity currents

The Wentworth scale is used to arrange the amount of sorting in a sediment deposit.
(a) True
(b) False

a. false

Underlying the unconsolidated sediments of the seafloor are __________.
(a) Basalt pillows and basement rocks
(b) Granite boulders
(c) Glacial deposits left from the Ice Age
(d) Ancient remnants of sunken continents

a. basalt pillows and basement rocks

Large volumes of bottom sediments may be transported long distances by __________.
(a) storm waves
(b) icebergs
(c) tidal action
(d) turbidity currents

d. turbidity currents

The processes which break rock and minerals into smaller particles are collectively termed
__________.
(a) metamorphism
(b) igneous activity
(c) weathering
(d) erosion
(e) fractionalization

c. weathering

Geologists classify sediment either by grain size or by source.
(a) True
(b) False

a. true

In volume and quantity, most marine sediments are associated with __________.
(a) the edges of the deep trenches
(b) the deep sea floor away from the continental slopes
(c) seamounts
(d) mid-ocean ridges
(e) the continental slopes and rises

e. continental slopes and rises

The most abundant sediment in the ocean is __________.
(a) terrigenous sediment
(b) biogenous sediment
(c) hydrogenous or authigenic sediment
(d) cosmogenous sediment
(e) all of these

a. terrigenous sediment

Sediments derived from preexisting rocks are called __________.
(a) cosmogenous
(b) biogenous
(c) hydrogenous
(d) lithogenous of terrigenous
(e) volcagenic

d. lithogenous or terrigenous

All of the following are lithogenous sediments except __________.
(a) beach sand
(b) diatom ooze
(c) glacial deposits
(d) illite clays
(e) volcanogenic particles

b. diatom ooze

Fine and coarse grains of sediment produced by weathering on land are termed __________ sediment.
(a) Biogenous
(b) Cosmogenous
(c) Hydrogenous
(d) Volcanogenic
(e) Terrigenous

e. terrigenous

Sediments that arrive in the ocean from continents via rivers are called __________.
(a) terrigenous sediments
(b) biogenous sediments
(c) hydrogenous or authigenic sediments
(d) cosmogenous sediments
(e) all of these

a. terrigenous

Abyssal clay is a type of __________.
(a) biogenous sediment
(b) cosmogenous sediment
(c) hydrogenous sediment
(d) terrigenous sediment

d. terrigenous

Sediments that are organic in origin, meaning made by organisms, are called __________.
(a) terrigenous sediments
(b) biogenous sediments
(c) hydrogenous or authigenic sediments
(d) cosmogenous sediments
(e) all of these

b. biogenous

Beach sand is usually well-sorted.
(a) True
(b) False

a. true

A glacial deposit is well-sorted.
(a) True
(b) False

b. false

A well-sorted sand deposit with rounded particles might be called immature.
(a) True
(b) False

b. false

The sediment that covers the greatest area of seabed is __________.
(a) terrigenous sediment
(b) biogenous sediment
(c) hydrogenous or authigenic sediment
(d) cosmogenous sediment
(e) all of these

b. biogenous

Fine and coarse sediments derived from the hard parts of organisms are termed __________.
(a) Biogenous
(b) Cosmogenous
(c) Hydrogenous
(d) Volcanogenic
(e) Terrigenous

a. biogenous

Sediment may be an accumulation of the remains or products of organisms.
(a) True
(b) False

(true)

Floating and drifting single-celled plants can be referred to as __________.
(a) Foraminiferans
(b) Radiolarians
(c) Zooplankton
(d) Phytoplankton
(e) Pteropods

d. phytoplanktons

Oozes are also called __________.
(a) terrigenous sediments
(b) biogenous sediments
(c) hydrogenous or authigenic sediments
(d) cosmogenous sediments
(e) all of these

b. biogenous sediments

The oozes on the seafloor mostly consist of __________.
(a) boulders and cobbles from glaciers oozing off the land
(b) bones and teeth of bottom-dwelling fishes
(c) fine muds washed down the continental slope to the seafloor
(d) microscopic hard parts of single-celled surface living organisms
(e) treated sewage from urban areas

d. microscopic hard parts of single-celled surface living organisms

Carbonate sediments composed of the shells of marine organisms are found __________.
(a) widely on all continental shelves
(b) on shelf areas that were exposed to the atmosphere during periods of glaciation
(c) only in the tropical Pacific
(d) only on land areas once covered with ocean water
(e) on some continental shelves in tropical and sub-tropical regions

e. on some continental shelves in tropical and sub-tropical regions

Coccolithophores, a type of phytoplankton, produce __________.
(a) biogenous sediment
(b) cosmogenous sediment
(c) hydrogenous sediment
(d) terrigenous sediment

a. biogenous sediment

Which of the following contains calcium carbonate (CaCO3)?
(a) diatoms
(b) foraminiferans
(c) glauconite
(d) phosphorites
(e) radiolarians

b. forminiferans

look at study guide

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Stromatolites are a type of __________.
(a) biogenous sediment
(b) cosmogenous sediment
(c) hydrogenous sediment
(d) terrigenous sediment

a. biogenous sediment

Diatomaceous ooze is a type of __________.
(a) biogenous sediment
(b) cosmogenous sediment
(c) hydrogenous sediment
(d) terrigenous sediment

a. biogenous sediment

Which of the following contains silica (SiO2)?
(a) coccolithophores
(b) corals
(c) foraminiferans
(d) phosphorites
(e) radiolarians

e. radiolarians

Calcareous shells will not accumulate on the ocean floor when the water depth exceeds about 4500
meters (around 15,000 feet).
(a) True
(b) False

a. true

The deposition of radiolarian oozes is affected by the carbonate compensation depth.
(a) True
(b) False

b. false

Radiolarian oozes form near the equator.
(a) True
(b) False

a. true

Sediments produced as a result of chemical reactions in seawater are called __________.
(a) cosmogenous
(b) biogenous
(c) hydrogenous
(d) lithogenous or terrigenous
(e) volcagenic

c. hydrogenous

Manganese nodules are an example of a _________.
(a) biogenous sediments
(b) cosmogenous sediments
(c) hydrogenous sediments
(d) terrigenous sediments
(e) volcagenic sediments

c. hydrogenous sediments

All of the following are hydrogenous sediments except _________.
(a) evaporites
(b) halites
(c) manganese nodule
(d) phosphates
(e) stromatolites

e. stromatolites

Sediments that are generated in place or on the spot where find them are called __________.
(a) terrigenous sediments
(b) biogenous sediments
(c) hydrogenous or authigenic sediments
(d) cosmogenous sediments
(e) all of these

c. hydrogenous or authigenic sediments

Sediment particles precipitated near the sea floor by chemical or biochemical reactions are termed
__________ sediments.
(a) Biogenous
(b) Cosmogenous
(c) Hydrogenous
(d) Volcanogenic
(e) Terrigenous

c. hydrogenous

Hydrogenous sediments are largely __________ precipitates that form in place.
(a) extraterrestrial
(b) inorganic
(c) biochemical
(d) volcanic

c. biochemical

Which of the following metals is not usually found in manganese nodules?
(a) iron
(b) uranium
(c) nickel
(d) cobalt
(e) copper

b. uranium

Sediments derived from weathered rock and volcanic activity are called biogenous sediments.
(a) True
(b) False

b.. false

Phosphate nodules are found on the continental shelf.
(a) True
(b) False

a. true

Organisms that live on the ocean floor may be responsible for keeping manganese nodules from being
buried in the sediment.
(a) True
(b) False

a. true

Halite is a type of __________.
(a) biogenous sediment
(b) cosmogenous sediment
(c) hydrogenous sediment
(d) lithogenous or terrigenous sediment

c. hydrogenous sediment

Manganese nodules are a type of __________.
(a) biogenous sediment
(b) cosmogenous sediment
(c) hydrogenous sediment
(d) lithogenous or terrigenous sediment

c. hydrogenous sediment

Metal sulfides are a type of __________.
(a) biogenous sediment
(b) cosmogenous sediment
(c) hydrogenous sediment
(d) lithogenous or terrigenous sediment

c. hydrogenous sediment

Sediments with an extraterrestrial origin are called __________.
(a) cosmogenous
(b) biogenous
(c) hydrogenous
(d) lithogenous or terrigenous
(e) volcagenic

a. cosmogenous

Tektites are a type of __________.
(a) biogenous sediment
(b) cosmogenous sediment
(c) hydrogenous sediment
(d) terrigenous sediment

b. cosmogenous sediment

look at study guide

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look at study guide

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look at study guide

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look at study guide

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Calcium carbonate is most likely to dissolve in water with which characteristics?
(a) low carbon dioxide and warm temperatures
(b) lots of carbon dioxide and cold temperatures
(c) lots of carbon dioxide and warm temperatures
(d) low pressure and warm temperatures
(e) low pressure and cold temperatures

b. lots of carbon and cold temperatures

The element found in some sediments which suggest that a meteorite or asteroid impact occurred
nearby is _________.
(a) iridium
(b) manganese
(c) strontium
(d) uranium
(e) yttrium

a. irridium

The most likely place to find abundant manganese nodules is on the _________.
(a) abyssal plain far from a continent
(b) continental rise
(c) continental shelf
(d) crest of a mid-ocean ridge
(e) All of the above locations are contain manganese nodules

a. abyssal plain far from a continent

In contrast to manganese nodules which form on the abyssal plain, phosphate-rich nodules form in
_________.
(a) continental shelf waters
(b) estuaries
(c) hydrothermal vent areas
(d) intermediate to shallow depth water
(e) mid-ocean ridge

d. intermediate to shallow depth water

Sediments found on continental margins are called _________.
(a) continental
(b) estuarine.
(c) neritic
(d) oceanic
(e) pelagic

c. neritic

In general, polar neritic sediment has more _________.
(a) clay than in temperate waters
(b) coral debris than in tropical waters
(c) rock and gravel than in tropical waters
(d) shell fragments than in temperate waters
(e) silt and sand than in tropical waters

c. rock and gravel than in tropical waters

A pelagic clay contains lots of material that settle to the seafloor through the water column and are
_________.
(a) less than 30% biogenous material
(b) more than 30% biogenous material
(c) more than 30% hydrogenous material
(d) less than 30% neritic material
(e) more than 30% neritic material

a. less than 30% biogenous material

A very important way to increase the settling rate of fine particles in the open ocean is via _________.
(a) carbonate dissolution
(b) deposit feeders
(c) fecal pellets
(d) precipitation
(e) wind

c. fecal pellets

Carbonate sediments are rare in deep sea sediments because __________.
(a) The organisms providing shells do not live in the deep sea
(b) The abundance of muds and clays cover the carbonate shells
(c) The carbonate shells dissolve in deep water
(d) The organisms do not live beyond the edge of the continental shelf

c. the carbonate shells dissolve in deep water

Most of the floor of the North Pacific Ocean is covered with __________.
(a) foraminiferan ooze
(b) windblown dust and sand
(c) red and brown clays
(d) diatom ooze

c. red and brown clays

The calcium sulfate and other substances found in the Mediterranean by Hsü and Ryan are classified
as __________.
(a) oozes
(b) evaporites
(c) clays
(d) terrigenous sediments
(e) poorly sorted sediments

b. evaporites

Sediments that are extraterrestrial in origin are called __________.
(a) terrigenous sediments
(b) biogenous sediments
(c) hydrogenous or authigenic sediments
(d) cosmogenous sediments
(e) all of these

d. cosmogenous sediments

This sediment type has particles that are sometimes made of glass.
(a) terrigenous sediment
(b) biogenous sediment
(c) hydrogenous or authigenic sediment
(d) cosmogenous sediment
(e) all of these

c. hydrogenous or authigenic sediment

Some ocean sediments have come from outer space.
(a) True
(b) False

a. true

This sediment type can be used to learn about the age and history of the seafloor.
(a) terrigenous sediments
(b) biogenous sediments
(c) hydrogenous or authigenic sediments
(d) cosmogenous sediments
(e) all of these

e. all of these

In the process of lithification, sediments __________.
(a) are subducted into the mantle at a deep trench
(b) are converted into solid rock
(c) slip into the center of the mid-ocean ridges and become new seafloor
(d) are uplifted to form the edges of continents
(e) are uplifted to form high mountains like Mt. Everest

b. converted into solid rock

Select the finest particles in this list __________.
(a) sand
(b) silt
(c) clay
(d) granules

c. clay

Scientists can derive information about __________ from observing deep ocean cores:
(a) basin age
(b) mineral resources
(c) water temperature in years past
(d) the history of life in the upper layers of water
(e) all of the above

e. all of the above

Very small particles sometimes fall surprisingly quickly from near the ocean surface to the seabed,
thus avoiding being carried great lateral distances by currents. This is possible because __________.
(a) the particles, though tiny, are very heavy and fall quickly
(b) the particles adhere to large particles and fall with them
(c) the particles are compressed in the fecal pellets of small marine animals
(d) the particles resist the action of currents and fall straight to the bottom

c. the particles are compressed in the fecal pellets of small marine animals

Paleoceanography is __________.
(a) the study of the ocean’s past
(b) analysis of sediment age by tektite content
(c) the study of ocean color
(d) analysis of the color of sediments
(e) none of the above

a. the study of ocean’s past

The oldest ocean floor sediments are about __________.
(a) 160 million years old
(b) 60 million years old
(c) 1 billion years old
(d) 6,000 years old
(e) 600 million years old

a. 160 million years old

The oldest sediments are comparatively young because __________.
(a) the rocks of the underlying ocean floor react chemically with the lowest sediments, converting
them directly into rock
(b) the ocean floor is recycled through plate tectonics, dragging the oldest sediments into the
mantle at subduction zones
(c) sediments have been falling to the ocean floor only comparatively recently
(d) the physical and biological processes that make sediments have been active only a
comparatively short time
(e) sediments are consumed by bottom-dwelling marine organisms

b. the ocean floor is recycled through plate tectonics, dragging the oldest sediments into the subduction zones

Dredge samplers are used to collect samples of __________.
(a) specific sediment types
(b) rock or sediment in bulk quantities
(c) bottom dwelling organisms
(d) suspended sediments
(e) buried sediments

b. rock or sediment in bulk quantities

The deepest sediment samples are obtained by __________.
(a) grab samplers
(b) piston corers
(c) gravity corers
(d) platform drilling

b. piston corers