Sediments

Question 1

what are marine sediments formed from

Answer 1

from weathered rock which gets transported to ocean by air/water

Question 2

is erosion/deposition equal

Answer 2

no because of plate tectonics, sediments squeezed at subduction zones mountains eroded into sea

Question 3

how to classify sediments

Answer 3

grain size

Question 4

what is mud

Answer 4

silt and clay, fine

Question 5

what are most common sediments in sea

Answer 5

mud/sand

Question 6

what does grain size/sorting show

Answer 6

how it was transported/deposited

Question 7

textural maturity

Answer 7

particles round overtime, sorting increases

Question 8

factors controlling deposition

Answer 8

energy of transport, material, size

Question 9

slow eroded rock

Answer 9

small/fine grain, well sorted, mature, mud/clay separated

Question 10

fast eroded rock

Answer 10

high energy, large grains, not well sorted, gravel/sand mixed

Question 11

high energy conditions

Answer 11

fine grains suspended, large grains roll, large grains deposited

Question 12

low energy conditions

Answer 12

large grains too heavy to suspend, fine grain deposited

Question 13

the larger the particle…

Answer 13

the larger the velocity needed to move it

Question 14

why does clay need more energy then sand

Answer 14

clay sticks together so needs more energy to break apart

Question 15

terrigenous/lithogenic

Answer 15

produced from weathered rocks, reflects composition of rocks where it was eroded, then gets transported by air/wind/ice

Question 16

biogenous

Answer 16

produced from hard shells of organisms, macroscopic (bones), microscopic (shells, small)

Question 17

hydrogenous

Answer 17

precipitated from water near seafloor, manganese nodules

Question 18

volcanogenic

Answer 18

ejected from volcanoes

Question 19

cosmogenic

Answer 19

from space

Question 20

where is most terrigenous/lithogenic sediment found

Answer 20

continental margins

Question 21

what does biogenic sediments do

Answer 21

settle on ocean and rains down ocean

Question 22

biogenic ooze

Answer 22

when biogenic sediment clumps together and forms ooze (organisms dissolve), 30% is ooze, rest is mud

Question 23

what happens after an organism dies

Answer 23

it sinks to floor and forms fecal pellat

Question 24

calcareous ooze

Answer 24

CaCO3, foraminifer, coccolithophores

Question 25

silicious ooze

Answer 25

high productivity areas, diatoms, accumulates past CCD

Question 26

deep ocean and CaCO3

Answer 26

its undersaturated with CaCO3, not enough calcium to combine with carbonate

Question 27

calcite compensation depth

Answer 27

depth where CaCO3 dissolves so there's none on seafloor

Question 28

carbonate dissolution depends on...

Answer 28

temperature/pressure, rate of carbonate supply, acidity

Question 29

lysocline

Answer 29

depth where CaCO3 declines rapidly

Question 30

factors controlling distribution

Answer 30

productivity, dissolution, dilution

Question 31

ferromanganese nodules

Answer 31

lumps of metal oxides that have precipitated around a nuclei, metals come from weathering of rock

Question 32

phosphorites

Answer 32

needed for growth of organisms, high productive areas

Question 33

evaporites

Answer 33

formed when water evaporates, minerals

Question 34

metal sulfides

Answer 34

iron/nickel, hydrothermal vents

Question 35

as you approach a continent there's more...

Answer 35

terrigenous sediment

Question 36

sources of deep sea sediment

Answer 36

terrigenous/biogenous

Question 37

bulk emplacement

Answer 37

large amount of sediment transported (not grains), moved due to gravity, sediment build up causes instability/slope failure

Question 38

slump

Answer 38

sediment piles slides downslope

Question 39

mud flows (slurries)

Answer 39

mud/sediment mixed with water

Question 40

turbidity currents

Answer 40

transport sediments to deep sea

Question 41

pelagic sediment

Answer 41

fine terrigenous/biogenic sediment settled at bottom of ocean

Question 42

inorganic

Answer 42

red clay

Question 43

organic

Answer 43

oozes

Question 44

continental shelf

Answer 44

flat plane of land underwater, where land meets sea

Question 45

what is shelf sedimentation controlled by

Answer 45

tides/waves/currents

Question 46

what happens to energy as depth increases

Answer 46

it decreases

Question 47

what does shoreline turbulence do

Answer 47

prevents small particles from settling

Question 48

where is calcareous ooze

Answer 48

tropics

Question 49

where is sand/mud

Answer 49

temperate

Question 50

subduction zones

Answer 50

squeeze sediment, creates prism

Question 51

ice rafting

Answer 51

bulk emplacement of terrigenous sediment, large ice fragments broken off glaciers

Question 52

as seafloor spreads...

Answer 52

ooze accumulates at top of ridge and gets buried/lithified and turns into limestone, as plate spreads it goes past CCD and ooze dissolves, pelagic mud forms and buries limestone protecting older limestone

Question 53

as continents move apart...

Answer 53

sediments fill gaps as plates move, terrigenous sediment eroded by continent accumulates on shelf causing it to widen, sediment weighs continent down/sinks so sediment can be deposited

Question 54

Atlantic margins

Answer 54

build up of sediment balances out subsidence, as plate sinks it has enough room for sediment build up

Question 55

pacific margins

Answer 55

same as subduction zones