Unit 6

Question 1

Where are the two main sediement archives located?

Answer 1

Germany & Japan

Question 2

What do sediments become after being lithified?

Answer 2

Sedimentary rock

Question 3

How is lithogenous sediment created?

Answer 3

pre-existing rock from land (continents/islands) from:
erosion
volcanic eruptions
blown dust

Question 4

Where is the highest deposition of lithogenous sediment?

Answer 4

Continental margin

Question 5

What are the 4 ways to transport lithogenous sediments? Give examples for each

Answer 5

1. Water (Yellowstone or Mississippi River)
2. Wind (Saharan Desert)
3. Ice
4. Gravity (landsildes)

Question 6

What is ice-rafted debris?

Answer 6

A way of dispersing lithogenous sediment:
1. sediments are locked into (obv frozen into) glacier
2. as glacier melts, sediments are released on the seafloor

Question 7

Where are some places to find lithogenous sediments?

Answer 7

• bays and lagoons
• deltas at river mouths
  -along beach shorelines
  -continental margin

Question 8

What mineral is most concentrated in lithogenous deposits? how would you know where to find them?

Answer 8

quartz; deposit of quartz tends to match global wind patterns

Question 9

Where is neritic sediment found?

Answer 9

continental shelves, close to shore, shallow waters

Question 10

Coarse or fine grain: neritic sediments

Answer 10

Coarse

Question 11

low or high energy to deposit: neritic sediments

Answer 11

HIGH

Question 12

Give some examples of neritic sediments:

Answer 12

• beach deposits (quartz rich sand)
• relict sediments
• turbidite deposits
• glacial deposists

Question 13

what are relict sediments?

Answer 13

A sediment lying on the continental shelf which was deposited by processes no longer active in the area where the sediment now occurs.

Question 14

what are pelagic sediments?

Answer 14

deep water deposits, finer grain, slowly deposits (LESS energy), open sea deposit location

Question 15

What are some examples of pelagic sediments?

Answer 15

• abyssal clay
• wind-blown dust
  -volcanic ash

Question 16

why is abyssal clay red

Answer 16

oxidized iron

Question 17

What are biogenous sediments? what are the 2 major types & which is more abundant?

Answer 17

derived from the remains of hard parts of once-living organisms

1. Macroscopic (shells, bones)
2. Microscopic (tiny shells or tests) MORE ABUNDANT

Question 18

What are tests?

Answer 18

the hard parts of microscopic organisms that make up biogenous sediment

Question 19

What are 2 types of biogenic ooze & what are they made up of?

Answer 19

1. siliceous (silica from diatoms and radiolarians
2. calcaerous (organisms that contain calcium carbonate)

Question 20

What is marine snow? Where does it land relative to where it is produced? How long does it take to land?

Answer 20

basically made from poop rockets of zooplankton
lands not far from production spot
10-15 days

Question 21

What are diatoms? Where can you find them?

Answer 21

= microscopic algae whose tests produce silica (siliceous ooze)
- photosynthetic (only found in upper, sunlit surface waters)

Question 22

How do diatoms move?f

Answer 22

they are free floating (planktonic) and drift with currents

Question 23

What are radiolarians? What is their main food source?

Answer 23

single cell protozoans (animals) whose tests produce silica (siliceous ooze)
- rely on food from the environment

Question 24

What is diatomaceous earth?

Answer 24

Lithified siliceous ooze that has many commercial uses

Question 25

What two organisms generate the calcium carbonate needed to make up calcareous ooze?

Answer 25

Coccolithophores & Foraminifera

Question 26

What are coccolithophores? Where are they commonly found?

Answer 26

micrscopic photosynthetic algae blooms found in high latitude areas

Question 27

What are foraminifera?

Answer 27

mostly planktonic (sometimes benthic) microscopic protozoans

Question 28

Difference between Planktonic and Benthic

Answer 28

Planktonic organisms float freely with currents while benthic organisms live on the bottom of bodies of water/within seafloor sediment

Question 29

What science are foraminifera useful for

Answer 29

paleoceanography (used to map what climate was like before)

Question 30

What is a lysocline?

Answer 30

depth at which CaCO3 (calcium carbonate) begins to dissolve rapidly

Question 31

What is the average lysocline?

Answer 31

4000m

Question 32

What is the CCD?

Answer 32

Calcite compensation depth

Question 33

What is the average CCD?

Answer 33

4500m

Question 34

Where is CaCO3 saturated? Under-saturated?

Answer 34

Warm, shallow oceans; cool, deep oceans

Question 35

Describe conditions below & above the CCD

Answer 35

Above CCD: calcite stable and not dissolved Below CCD: different conditions cause calcite to dissolve

Question 36

How is there calcareous ooze BELOW the CCD?

Answer 36

seafloor spreading (mid-ocean ridge)

Question 37

waht are some factors that determine there are enough test/skeltons to consider ocean sediment biogenous?

Answer 37

- productivity - dissolution/destruction - dilution

Question 38

what are hydrogenous sediments made from?

Answer 38

materials dissolved in the water

Question 39

what is precipitation?

Answer 39

change from the dissolved to the solid state resulting from a change in conditions

Question 40

name 5 different types of hydrogenous sediments

Answer 40

- manganese nodules - phosphates - carbonates - metal sulfides - evaporites