marine sediments

Question 1

divergence

Answer 1

spread apart

Question 2

convergence

Answer 2

come together

Question 3

what is sea floor spreading ?

Answer 3

Seafloor spreading is the continuous process of forming new igneous rock at midocean ridges by injection of magma that forms new seafloor

Question 4

marine sediments

Answer 4

particles of various size from various sources and are deposited on the marine floor

Question 5

what are the inputs of sediments to the ocean

Answer 5

Rivers (most)
Glaciers
Wind
Erosion
Volcanic debris
Ground water (least)

Question 6

how are marine sediments produced ?

Answer 6

through chemical or physical weathering

Question 7

What is physical weathering?

Answer 7

physical processes that cause rock fragmentation

Question 8

what is chemical weathering

Answer 8

chemical reactions that alter rocks

Question 9

what are the classifications of marine sediments

Answer 9

gravel (largest) , sand, silt and clay(smallest)

Question 10

is mud a mixture of silt and clay?

Answer 10

yes

Question 11

what what are the different marine sediment origins

Answer 11

Terrgienous, Biogenous, Authigenic(Hydrogenous), Cosmogenous

Question 12

what indicates terrigenous origin ?

Answer 12

Eroded rock, volcanoes or airborne dust . basically anything created by terrain.

Question 13

which sediment origins are internal and which are external ?

Answer 13

internal: terrestrial

external: biogenic or authigenic

Question 14

terrigeneous material is typically is from

Answer 14

-rivers, 10^6 tons a year
-glaciers, they melt and their frozen debris settles on the ocean floor
-winds, aka aeolian dust
coastal erosion
-turbidities

Question 15

what are the 3 major ocean basins

Answer 15

Pacific, Atlantic, Indian

Question 16

what are turbidites?

Answer 16

rapidly accumulated terrestrial sediments like when earthquakes trigger avalanches

Question 17

where can you find most terrigenous material

Answer 17

Dominantly neritic, pelagic in areas of low productivity

Examples: coarse beaches and shelf deposits

Question 18

biogenous means

Answer 18

sediments from living things

Question 19

biogenies material is typically made of ___

Answer 19

shells from planktonic organisms

Question 20

the shells that make biogenies material are made from what ?

Answer 20

the shells are typically composed of either calcium carbonate or silica

Coccolithophores foraminifers and pteropods produce calcareous debris

Question 21

where is biogenous material found ?

Answer 21

In regions of high productivity, dominantly pelagic , areas of upwelling, some beaches, shallow warm weather.

(basically areas where plankton can grow abundantly and die)

Question 22

authigenic or hydrogenous material is from ___

Answer 22

chemical precipatation reaction in the sea water.

Question 23

where can you find authigenic/hydrogenous material ?

Answer 23

Mid ocean ridges, areas starved of other sediment types, neritic and pelagic

Question 24

what typically makes authigenic/hydrogenous sediment ?

Answer 24

Metal sulfides, manganese nodules, phosphates, some carbonates

Evaporites— salt deposits

Question 25

cosmogenous material means

Answer 25

from space

Question 26

where can you find cosmogenous material ?

Answer 26

Areas of significant deposit: Everywhere but in low concentration.

Question 27

what is an example of cosmogenous material ?

Answer 27

meteorites and space dust

Question 28

when referring to internal and external sediments, what do the term internal and external mean ?

Answer 28

internal means from the lan external means from the sea

Question 29

what is paleoceanography

Answer 29

study of Earth’s oceanographic history involving the analysis of the ocean’s sedimentary record, the history of tectonic plate motions, glacial changes, and established relationships between present sedimentation patterns and environmental factors.

Question 30

what are the different types of core samples

Answer 30

piston, gravity, multicore

Question 31

briefly explain the types of core samples

Answer 31

piston: pistol, shoot the ground gravity: heavy weight pushes into the ground multicore: same as gravity, but with multiple core samples

Question 32

how are dredged rocks collected ?

Answer 32

collected by dragging an open steel box with an attached chain bag along the ocean bottom behind a ship.

Question 33

Do biogenous sediments dissolve readily at shallow depths on the continental shelf?

Answer 33

no

Question 34

Do plankton species in coastal waters lack skeletons

Answer 34

no

Question 35

Are planktonic organisms consumed by large organisms, preventing deposition of skeletons?

Answer 35

no

Question 36

rivers are 10 times more ____ than ____

Answer 36

terrigenous : biogenic

Question 37

The large input of terrigenous sediment to the continental margin overwhelms the biogenous component in the sediment. This explains what?

Answer 37

why biogenous oozes are rarely found near the shore

Question 38

Why do red clays dominate far from land in great water depths?

Answer 38

Minimal sediment input from land – Far from coasts, little sediment is delivered from rivers or erosion. Slow sedimentation rates – Very little material accumulates in deep-sea environments, allowing fine red clays to settle. Wind-blown dust – Fine particles from deserts are carried by wind over long distances and eventually settle in the deep ocean. Low biological activity – In deep waters, there’s less biogenic material (like shells or skeletons), especially below the carbonate compensation depth (CCD), where calcium carbonate dissolves. Iron oxides – Red clays get their color from iron oxide, which accumulates over time in the oxygenated deep ocean.