OCE 1001 Exam 1

What is the approximate depth of the calcite compensation depth (CCD) in the ocean?

3 miles (4.5 kilometers)

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

Judge the following sentence according to the criteria given below: Biogenous sediment usually contains abundant calcite below the calcite compensation depth BECAUSE it readily dissolves above the calcite compensation depth.

Both the assertion and the reason are incorrect.

Depth at which all calcium carbonate is in solution (i.e. dissolved)

CCD

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.

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 of the following is the main reason that Earth has a magnetic field?

Convection in the liquid iron-nickel outer core generates a magnetic field.

Tektites are an example of which of the following sediment types?

Cosmogenous Sediment

Which of the following is thought to have enriched ocean floor sediments with rare-earth elements?

Deep-sea hotsprings

Which type of plate boundary is most closely associated with the formation of new ocean floor?

Divergent

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

Dredge

Which of the following statements about Earth's magnetic field is most accurate?

Earth's magnetic field switches polarity at irregular time intervals

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

Associated with glacial deposits

Ice Rafting

Sandstone 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

Of the following, which energy resource(s) can be extracted from marine sediments? Choose all that apply.

Petroleum Gas hydrates

China currently supplies about 90% of which of the following resources?

Rare-earth elements

Depression along a ridge axis

Rift valley

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

Rotary corer

Wegener used which of the following to provide evidence for continental drift?

Shape of continental margins

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern.

Stanley Miller

Sloping area from a trench along a downward moving plate

Subduction zone

Judge the following sentence according to the criteria given below: An increase in atmospheric carbon dioxide due to the burning of coal will cause the calcite compensation depth to rise BECAUSE the oceans will get more acidic.

The assertion and the reason are both correct, and the reason is valid.

Judge the following sentence according to the criteria given below: Abyssal clays are commonly red-brown or buff in color BECAUSE they contain gypsum.

The assertion is correct, but the reason is incorrect.

Judge the following sentence according to the criteria given below: Marine sediments can't provide insight into today's climate changes BECAUSE they reveal a detailed history of Earth's past climate.

The assertion is incorrect, but the reason is correct.

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

The deep-ocean floor

Of the following statements about Earth's magnetic field, which is/are true? Choose all that apply.

The lines of the magnetic force are perpendicular relative to Earth's surface at the magnetic south pole. The magnetic north pole may reverse so that it is located near the geographic south pole. The lines of the magnetic force are parallel with Earth's surface at the equator. The lines of the magnetic force are perpendicular relative to Earth's surface at the magnetic north pole.

Which of the following statements is true of the lithosphere?

The lithosphere is composed of the crust and the uppermost portion of the mantle.

Associated with submarine canyons and deep-sea alluvial fans

Turbidite

Particle size classification

Wentworth Scale

What is calcareous ooze?

a fine-grained, deep ocean sediment containing the skeletal remains of calcite-secreting microbes

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

Sediments derived from the remains of the hard parts of once-living organisms are called __________ sediments.

biogenous

Two common types of chemical compounds found in biogenous sediments are __________ and __________.

calcium carbonate; silica

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

Calcite dissolves more readily in seawater that is ________ in temperature and ________ in pressure.

colder; higher

Sediments with an extraterrestrial origin are called:

cosmogenous

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

The two major types of microscopic, planktonic organisms that produce siliceous oozes are __________ and __________.

diatoms; radiolarians

The deposition of coarse-grained lithogenous material in neritic environments along continental margins is an example of the ________ of biogenous sediment.

dilution

Forams, which are composed of calcium carbonate, __________ above the CCD and __________ below the CCD.

do not dissolve; dissolve

All continents fit together with the least number of overlaps and gaps when the continents are matched along ________.

edges at around 2,000 meters depth

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

gravel than in tropical waters

Siliceous ooze is particularly abundant on the seafloor at __________ and at __________.

high latitudes; equatorial upwelling zones

Sediments produced because of chemical reactions in seawater are called:

hydrogenous

Salt beds of the U.S. Gulf Coast are __________.

hydrogenous sediments

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

hydrogenous sediments cosmogenous sediments

Moving from an oceanic ridge to an oceanic trench, the thickness of the lithosphere:

increases in proportion to the distance.

Climate distribution on Earth is primarily controlled by:

latitude.

Sediments derived from pre-existing rocks on land are called:

lithogenous

Tectonic plates are pieces of the ________ that float on the more fluid ________ below.

lithosphere; asthenosphere

Calcium carbonate is most likely to dissolve in water with which characteristic?

low salinity

Fossils of ancient tropical plants are currently found near the poles because the:

plants lived in the tropics, but landmasses have drifted to current locations.

The most abundant mineral in lithogenous sediments is __________.

quartz

Neritic sediments are most likely to be composed of __________.

sand, silt, and gravel

The particles found in some sediment that suggests that an extraterrestrial impact event are:

tektites

In which of the following environments would you expect lithogenous sediment to be the dominant sediment type? Choose all that apply.

the abyssal plains a sandy beach at the base of the continental slope along the mid-ocean ridge

Marine sediments provide valuable clues about which of the following Earth history events? Choose all that apply.

the climate on Earth millions of years ago the ancient geographical locations of ocean basins past catastrophes, such as major extinction events previous ocean circulation patterns movement of the ocean floor

In the demonstration, what does the apple represent?

the deep sea floor

What mechanism(s) is/are responsible for transporting clay to deep ocean basins? Choose all that apply.

wind slow-moving ocean currents

The first person to advance the idea of mobile continents or continental drift was:

Alfred Wegener.

Which of the following rocks is the most reliable one used to collect information about Earth's magnetic field where and when the rock originated?

Basalt

Fossiliferous limestone is 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

Which of the following marine resources is used to make wallboard or sheet rock?

Evaporative salts

The book The History of Ocean Basins, which contained the idea of seafloor spreading, was written by geologist:

Harry Hess.

Oolites are an example of which of the following sediment types?

Hydrogenous Sediment

Depth at which calcium carbonate begins to dissolve

Lysocline

Which of the following fossils was used as data to help reconstruct Pangea because it was a reptile found in South America and Africa?

Mesosauras

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

Of the following statements about ocean crust, which is/are true? Choose all that apply.

Ocean crust is destroyed at deep sea trenches. Ocean crust is created at the mid-ocean ridge.

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern

Oolites

Which of the following was not used as evidence for continental drift?

Paleomagnetic reversals

Study of magnetism over geologic time

Paleomagnetism

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern.

Panamerica

Supercontinent 250 million years ago

Pangaea

Ancient precursor of the Pacific Ocean

Panthalassia

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

Petroleum

How does siliceous ooze accumulate on the seafloor if silica-based residues are dissolved slowly at all depths?

Silica tests accumulate faster than seawater can dissolve them.

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern

Siliceous ooze

Judge the following sentence according to the criteria given below: Coarse-grained lithogenous neritic deposits dominate continental margin areas BECAUSE they do not contain biogenous, hydrogenous, and cosmogenous particles.

The assertion is correct, but the reason is incorrect.

Alfred Wegener's continental drift hypothesis received much hostile criticism and ridicule from the scientific community because of which of the following?

The mechanism he proposed for the movement of the continents.

Why does the sea floor have a striped pattern of magnetic anomalies that is symmetric with respect to the mid-ocean ridge? Choose all that apply.

The ocean floor is spreading apart and new sea floor is forming. The igneous rock of the ocean floor preserves Earth's existing magnetic field as the rock cools. The polarity of Earth's magnetic field experiences reversals.

Of the following statements about the age of the ocean crust, which one is true?

The oldest ocean crust is about 200 million years old and is located near an ocean trench.

Which of the following statements about marine sediments is correct?

They record the timing and severity of some global extinction events.

Which of the following lines of evidence did Alfred Wegener use to support the concept of drifting continents? Choose all that apply.

evidence of glaciers in areas that are now tropical the distribution of species of fossils the way the shapes of the continents fit together like pieces of a jigsaw puzzle the pattern of similar mountain belts on different continents

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

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

gas hydrates

Frederick Vine and Drummond Matthews determined that new ocean floor was being produced at ocean ridges by examining:

the magnetic pattern of rocks on the seafloor.

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