OCE1001 Ch 4
What is the approximate depth of the calcite compensation depth (CCD) in the ocean?
3 miles (4.5 kilometers)
On average, at what ocean depth does calcite readily dissolve into seawater?
4500 meters (14,764 feet)
Part C
A: Abyssal clay B: Calcareous ooze C: Mid-ocean ridge D: Calcite compensation depth (CCD) E: Siliceous ooze F: Upwelling, cool water
Part E
A: Abyssal clay B: Calcareous ooze C: Siliceous ooze
Part B
A: Coccolithophores (multiple) B: Foraminifers C: Coccoliths (individual plates) D: Coccolithophore (single) E: Diatom (siliceous)
Part A
A: Diatom, showing both halves of its test B: Radiolarian, showing long appendages C: Radiolarian, spherical shape D: Diatom, top view
Part D
A: Siliceous ooze: diatom B: Abyssal clay C: Neritic continental lithogenous D: Calcareous ooze E: Siliceous ooze: radiolarian
Why is this drilling process called rotary drilling?
Because the drill bit turns around in a circle.
Why does calcareous material dissolve below the CCD?
Below the CCD, weak acid is formed, which dissolves calcareous material.
Calcareous ooze is an example of which of the following sediment types?
Biogenous Sediment
Siliceous ooze is an example of which of the following sediment types?
Biogenous Sediment
What would happen if the depth of the CCD were above the top of the mid-ocean ridge?
Calcareous ooze would not be found below the CCD.
Which of the following are microscopic, single-celled floating algae that accumulate to form biogenous sediment? Choose all that apply.
Coccolithophores Diatoms
Micrometeorites are an example of which of the following sediment types?
Cosmogenous Sediment
Which of the following contains the most organic carbon on Earth?
Gas hydrates
Which of the following is a hollow steel tube with a heavy weight on top that is to collect sediment samples?
Gravity corer
Oolites are an example of which of the following sediment types?
Hydrogenous Sediment
Rock salt (halite) is an example of which of the following sediment types?
Hydrogenous Sediment
Abyssal clay is an example of which of the following sediment types?
Lithogenous Sediment
Turbidite deposits are an example of which of the following sediment types?
Lithogenous Sediment
Which of the following natural gasses is most common in gas hydrates from under the ocean floor?
Methane
The ancient remains of which of the following, buried before they could decompose, are the source of today's petroleum deposits?
Microscopic organisms
What percentage of the rocks exposed on the continents originated as sedimentary rocks deposited in ancient ocean environments?
More than fifty percent
The most likely place to find abundant manganese nodules is on the:
abyssal plain far from a continent.
What common household item is used in this video to demonstrate rotary drilling?
an apple corer
What factor primarily determines the distribution of radiolarian ooze?
areas of upwelling
Which of the following are examples of neritic sediments?
beach sand evaporite deposits
Sediments produced by plants and animals in the sea are called:
biogenous.
Which of the following sediments would you expect to find in a lagoon?
broken bits of coral salt
What have oceanographers determined from analyzing sea floor cores?
climate change and past extinctions
Which sediment type dominates in the neritic environment?
coarse lithogenous sediment, such as sand and small rocks
Of the following sediments, which one(s) is/are considered hydrogenous? Choose all that apply.
coatings of metal sulfides near black smokers manganese nodules
Sediments derived from pre-existing rocks on land are called:
lithogenous
Marine sediments provide valuable clues about which of the following Earth history events? Choose all that apply.
movement of the ocean floor past catastrophes, such as major extinction events the ancient geographical locations of ocean basins previous ocean circulation patterns the climate on Earth millions of years ago
The type of marine sediment that forms the thickest deposits worldwide is:
neritic, lithogenous sediment deposits.
Where on the ocean floor do abyssal clays develop?
on the deep-ocean floor, far from land
The number of organisms present in the surface water above the ocean floor is called ________.
productivity
Glacial deposits are an example of which of the following sediment types?
Lithogenous Sediment
Sandstone is an example of which of the following sediment types?
Lithogenous Sediment
Shale is an example of which of the following sediment types?
Lithogenous Sediment
Of the following types of lithogenous sediment, which one(s) would you expect to find very far from the location of origin? Choose all that apply.
Quartz silt Volcanic ash
Which of the following is the most advanced technology used to collect sediment samples from the deep ocean?
Rotary corer
Where might one find calcareous oozes on the seafloor?
buried beneath siliceous oozes along the crests of mid-ocean ridges, above the CCD buried beneath abyssal clay
Which sediment below cannot accumulate below the CCD?
calcareous tests
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
From smallest to largest, which list of sediment particle sizes is in the correct order?
clay, silt, sand, pebbles
Sediments with an extraterrestrial origin are called:
cosmogenous
Which of the following factors affect the distribution of biogenic oozes on the seafloor?
dissolution biological productivity water depth seafloor spreading
Forams, which are composed of calcium carbonate, __________ above the CCD and __________ below the CCD.
do not dissolve; dissolve
Diatomaceous earth, which is composed of silica, __________ above the CCD and __________ below the CCD.
does not dissolve; does not dissolve
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
Sediments produced because of chemical reactions in seawater are called:
hydrogenous
What sediment type(s) is/are included in the pink category labeled "Other" on the map?
hydrogenous sediments cosmogenous sediments
High-energy environments are most likely to deposit which one of the following?
large particles such as gravel
Neritic sediments are most likely to be composed of __________.
sand, silt, and gravel
In the demonstration, what does the apple represent?
the deep sea floor
What is the calcite compensation depth, or CCD?
the ocean depth below which calcite is unstable and will dissolve quickly
Which of the following are examples of pelagic sediments?
volcanic dust biogenic ooze abyssal clay
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
Terrigenous sediment is another name for which of the following?
Lithogenous Sediment
What three steps are required for calcareous ooze to exist below the CCD?
deposition of calcite shells above the CCD, cover of these shells by a non-calcareous material, and movement of the sea floor over millions of years
Which of the following organisms thrive in cold surface waters?
radiolarians siliceous organisms diatoms
Of the following, which energy resource(s) can be extracted from marine sediments? Choose all that apply.
Petroleum Gas hydrates
Ocean sediments consist of particles that have slowly settled out of the water by which of the following the processes?
Suspension settling
Collecting adequate samples from which of the following is the most difficult?
The deep-ocean floor
Why do some organisms thrive in warm surface waters?
Warm water is generally saturated in carbonate.
What is calcareous ooze?
a fine-grained, deep ocean sediment containing the skeletal remains of calcite-secreting microbes
Sediments that are poorly sorted were most likely deposited by:
a glacier.
