Exam 1 Chapter 4
In which of the following environments would you expect to find lithogenous sediment? (3)
a muddy lagoon a sandy beach at the base of the continental slope
Which of the following organisms are responsible for the creation of siliceous ooze? (2)
Radiolarians Diatoms
Which of the following is the most abundant component by weight for deep-ocean sediments?
Clay
Which of the following are microscopic, single-celled floating algae that accumulate to form biogenous sediment? (2)
Coccolithophores Diatoms
Most chalk is made from ___________.
Coccoliths
Beneath the calcite compensation depth (CCD), ___________.
calcium carbonate dissolves in seawater
Which of the following statements about biogenous oozes is FALSE?
Biogenous oozes are created by underwater eruptions, which cover the sea floor with fine ash particles.
Because they tend to move downslope, most lithogenous sediments are deposited in abyssal plains.
False
Black volcanic beach sand is a type of hydrogenous sediment.
False
The calcite compensation depth (CCD) represents the depth where wave action ceases to form calcareous oolites.
False
All of the following are examples of sediment-transporting media EXCEPT ___________.
Levitation
Which of the following statements about manganese nodules is FALSE?
Manganese nodules are a type of foraminifer.
Of the following statements about surface water temperature above biogenous sea floor deposits, which is/are true? (2)
Siliceous ooze on the sea floor indicates cool surface water above. Calcareous ooze on the sea floor indicates warm surface water above.
Microscopic shells that create biogenous sediment on the sea floor are called ___________.
Tests
Which of the following statements about the Deep Sea Drilling Project (DSDP) is FALSE?
The DSDP drilled to the center of Earth and confirmed that the outer core is composed of liquid iron-nickel material.
Which of the following conditions allows for calcareous ooze to be found beneath the CCD?
The ooze accumulates above the CCD and then is covered before being transported to deeper depths by sea floor spreading.
Which of the following is the most fine-grained sediment?
abyssal clay
Of the following environments, in which one(s) would lithogenous sediment (of any amount) be found? (All/5)
abyssal plains continental shelves continental rises continental slopes deep-ocean trenches
Where are most modern-day calcareous oozes found in the ocean?
along the mid-ocean ridge beneath warm surface waters
ow is most sediment transported from the continental shelf out to the continental rise?
by turbidity currents
Of the following sediments, which one(s) is/are considered hydrogenous? (2)
coatings of metal sulfides near black smokers manganese nodules
Populations of microscopic marine organisms in ocean surface waters closely match their abundance in sediments on the ocean floor, even though it takes 10 to 50 years for an individual particle to sink to deep-ocean depths. What accounts for this pattern?
concentration of the particles in fecal pellets.
In sediments, what does the Wentworth scale describe?
grain size
Of the following environments, where would you expect to find large amounts of lithogenous sediment? (2)
in deep trenches not far offshore on the continental shelf
Lithogenous sediments are ___________.
made of material derived from pre-existing rock material
Of the following sediments, which one(s) is/are considered biogenous? (2)
tests of foraminifers radiolarian ooze
Marine sediments provide valuable clues about which of the following Earth history events? (All/5)
the ancient geographical locations of ocean basins previous ocean circulation patterns the climate on Earth millions of years ago past catastrophes, such as major extinction events movement of the ocean floor
The only way for siliceous ooze to be preserved in the ocean is ___________.
to have it accumulate faster than it dissolves
Calcareous ooze is associated with ________ surface water conditions, and siliceous ooze is associated with ________ surface water conditions.
warm; cool
