OCE1001 Chapter 4

Why does water frozen in the cracks of a rock help to break down the rock?

Water expands when frozen and physically forces the rock apart

Biogenous sediments are indicated by the number(s):

2, 3, & 4

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

3 miles (4.5 kilometers)

Calcareous oozes are represented by the number(s):

4

On the world ocean pie diagram below, match the percentage to the correct type of sediment.

A. Abyssal clay B. Calcareous ooze C. Siliceous ooze

This composite photomicrograph image shows various types of calcareous marine microorganisms that are found in sediment. Match the correct letter to the name and correct description of each organism listed below.

A. Coccolithophores (multiple) B. Foraminifers C. Coccoliths (individual plates) D. Coccolithophore (single) E. Diatom (siliceous)

A. siliceous ooze B. quartz sand C. rock fragments D. clay E. volcanic ash

A. Siliceous Ooze

As a whole, the pH of surface waters of the ocean is slightly __________.

Alkaline

What common household item is used in this video to demonstrate rotary drilling?

An apple corer

Match the term or person with the appropriate phrase. ice rafting

Associated with glacial deposits

A. biogenous B. calcareous C. cosmogenous D. hydrogenous E. lithogenous

B. Calcareous

Why is this drilling process called rotary drilling?

Because the drill bit turns around in a circle

What are the three types of loads carried by streams?

Bed load, suspended load, dissolved load

Why does calcareous material dissolve below the CCD?

Below the CCD, weak acid is formed, which dissolves calcareous material

Match the term or person with the appropriate phrase. coccolithophores

Biogenous sediment

The depth at which calcite dissolves rapidly in the ocean is called the __________.

Calcite compensation depth or CCD

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

Which way does ice flow in a glacier retreating uphill?

Downslope

A. halite and other salts B. manganese nodules C. metal sulfides D. phosphates E. tektites

E. Tektites

Match the term or person with the appropriate phrase. manganese nodules

Hydrogenous sediment

Match the term or person with the appropriate phrase. metal sulfides

Hydrogenous sediment

Of the following environments, where would you expect to find large amounts of lithogenous sediment?

In deep trenches not far offshore On the continental shelf

Phosphate-rich nodules form in:

Intermediate to shallow depth water

Complete this analogy: Sliding is to gravel as dissolution is to_____________.

Ions

Pelagic clays contain lots of material that settles to the seafloor through the water column and are:

Less than 30% biogenies material

Match the term or person with the appropriate phrase. Wentworth Scale

Particle size classification

The most abundant mineral in lithogenous sediments is __________.

Quartz

What can you infer about the ocean environment from a core sample composed of the following layers: siliceous ooze (youngest layer) calcareous ooze basalt rock (oldest layer)

The core was collected in a region of high surface productivity in water deeper than 4,500 meters.

The cross-section below shows an area of the sea floor that is accumulating sediments. Match the type of sediment/feature with the correct letter.

A. Abyssal clay B. Calcareous ooze C. Mid-ocean ridge D. Calcite compensation depth (CCD) E. Siliceous ooze F. Upwelling, cool water

Calcareous ooze is found in cooler waters at depth around the world.

False

Macroscopic biogenous sediment is the most abundant biogenous sediment in the marine environment.

False

The pH scale is a measure of the __________ ion concentration of a solution.

Hydrogen

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

Lithogenous

Match the term or person with the appropriate phrase. abyssal clay

Lithogenous (terrigenous) sediment

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

Low salinity

All the following statements are true of ocean sediments except :

Ocean sediments are thickest in pelagic waters overlying the oceanic ridges

Which of the following contains silica (SiO2)?

Radiolarians

How can pieces of rock in contact with a stream bed move?

Rolling, sliding, bouncing

Sediment samples from deep beneath the ocean floor are recovered by __________.

Rotary Drilling

Which of the following are part of the bed load? CHOOSE ALL THAT APPLY.

Sand Gravel

Neritic sediments are most likely to be composed of __________.

Sand, silt, and gravel

All the following are examples of hydrogenous sediment except :

Stromatolites

In the demonstration, what does the apple represent?

The deep sea floor

What is suspended load?

The fine-grained particles that travel in the water column above the stream bed

What is salt weathering?

The formation of minerals in rock cracks during the evaporation of salty water, forcing rock apart.

How would you expect the front of a glacier to move if it undergoes a period of net accumulation, followed by net wastage, and finally a period of net accumulation?

The glacier's front would move forward, backward, and then forward again.

Which is the best definition of glacial snow line?

The line dividing zones of accumulation and melting of ice at the surface of a glacier

How would a snow line on a glacier move as a glacial front is advancing?

The snow line would move downslope

Calcareous shells generally will not accumulate on the ocean floor when the water depth exceeds about 4,500 meters (around 15,000 feet).

True

Calcium carbonate, phosphates, and manganese may precipitate out of solution to form deposits on the ocean floor.

True

Organisms that live on the ocean floor may be responsible for keeping manganese nodules from being buried in the sediment.

True

Sediments with an extraterrestrial origin are called:

Cosmogenous

A. coccolithophores B. diatoms C. foraminiferans D. oolites E. radiolarians

D. Oolites

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

Match the term or person with the appropriate phrase. CCD

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

All the following are examples of lithogenous sediment except :

Diatom Ooze

Which of the following organisms are responsible for the creation of siliceous ooze?

Diatoms Radiolarians

Sediments derived from weathered rock and volcanic activities are called biogenous sediments.

False

Under what conditions will the front of a glacier remain stationary?

Glacial fronts remain stationary when melting and snow accumulation are equal

Texture refers to the size and shape of sediment particles.

True

The organisms that contribute to biogenous sediment are chiefly algae and protozoans.

True

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

This composite photomicrograph image shows various types of siliceous marine microorganisms that are found in sediment. Match the correct letter to the name and correct description of each organism listed below.

A. Diatom, showing both halves of its test B. Radiolarian, showing long appendages C. Radiolarian, spherical shape D. Diatom, top view

This global map shows the distribution of different types of marine sediment (different colors). Match the correct letter to the sediment type listed below.

A. Siliceous ooze: diatom B. Abyssal clay C. Neritic continental lithogenous D. Calcareous ooze E. Siliceous ooze: radiolarian

Marine sediments that originate in the warm tropical surface ocean would create deposits in the deep sea composed primarily of ___________.

Calcium Carbonate

Carbon dioxide (CO2) combines with water (H2O) to form __________.

Carbonic acid (H2CO3)

The presence of what type of macroscopic sediment would provide evidence of a meteorite impact on Earth?

Chondrites

The sea floor provides the largest reservoir of usable energy in the ocean—and likely the world—in the form of ______________.

Clathrates

Complete this analogy: Bouncing is to sand as suspension is to_____________.

Clay

What have oceanographers determined from analyzing sea floor cores?

Climate change and past extinctions

Ocean sediments provide all the following mineral resources except :

Coal

Of the following sediments, which one(s) is/are considered hydrogenous?

Coatings of metal sulfides near black smokers Maganese nodules

What is the calcite compensation depth, or CCD?

The ocean depth below which calcite is unstable and will dissolve quickly

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.

What do manganese nodules, metal sulfides, and evaporites all have in common?

They all precipitate from water oversaturated in their respective minerals

What do freeze-thaw and salt weathering have in common?

Both freeze-thaw and salt weathering require rain and force rocks apart physically

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?

Coccolithophores Diatoms

Calcite-secreting organisms such as __________ and __________ live in the ocean's sunlit surface waters and form the basis of most marine food webs.

Coccolithophores; foraminifers

Marine sediment with more than 30% biogenous material is called __________.

Ooze

You add sand, silt, and clay to a jar of water, shake the jar vigorously, and allow the sediment to settle. The resulting sediment will most closely resemble that of a(n) __________.

Continental rise