last fall hw
What is the average CCD depth below sea level?
15,000 feet
Siliceous ooze contains at least ________% of the hard remains of silica-secreting organisms.
30
Manganese nodules grow about ________ per million years.
5 millimeters
China supplies approximately ________ of the current world demand of rare-earth elements
90%
which of the following conditions allows for calcareous ooze to exist beneath the CCD?
A layer of clay buries the ooze before the sea floor subsides.
Which of the following is the most dominant sediment in the deepest ocean basin - the North Pacific?
Abyssal clay
Stromatolites are an example of which of the following sediment types?
Biogenous Sediment
The White Cliffs of Dover are 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.
What does CCD stand for?
Carbonate compensation depth
The presence of what type of macroscopic sediment would provide evidence of a meteorite impact on Earth?
Chondrites
Which of the following contains the most organic carbon on Earth?
Gas hydrates
Which one of the following is the most common types of foraminifer ooze?
Globigerina
Demand for which of the following resources has skyrocketed in recent years?
Rare-earth elements
What do manganese nodules, metal sulfides, and evaporites all have in common?
They all precipitate from water oversaturated in their respective minerals.
What is calcareous ooze?
a fine-grained, deep ocean sediment containing the skeletal remains of calcite-secreting microbes
Which of the following are examples of pelagic sediments?
abyssal clay, volcanic dust, biogenic ooze
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
Which sediment below cannot accumulate below the CCD?
calcareous tests
The sea floor provides the largest reservoir of usable energy in the ocean, and likely the world, in the form of ______________.
clathrates
You take a sediment sample from the ocean floor at a depth of 5500 m. The area has low biological productivity and the CCD is at 4500 m depth. Your sample will probably consist of __________.
clay
Which sediment type dominates in the neritic environment?
coarse lithogenous sediment, such as sand and small rocks
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
A very important way to increase the settling rate of fine particles in the open ocean is via:
fecal pellets.
Which of the following contains calcium carbonate (CaCO3)?
foraminiferans
Calcium carbonate is most likely to dissolve in water with which characteristic?
high carbon dioxide concentration
Cosmogenous sediment consists of two main types of sediment:
microscopic spherules and macroscopic meteor debris.
Where on the ocean floor do abyssal clays develop?
on the deep-ocean floor, far from land
Of the following, which energy resource(s) can be extracted from marine sediments?
petroleum, gas hydrates
Which of the following contains silica (SiO2)?
radiolarians
Which of the following sediments would you expect to find in a lagoon?
salt, broken bits of coral
What mechanism(s) is/are responsible for transporting clay to deep ocean basins?
slow-moving ocean currents, wind
What is the calcite compensation depth, or CCD?
the ocean depth below which calcite is unstable and will dissolve quickly
What factor primarily controls the distribution of calcareous ooze?
water depth
