Sedimentology

Question 1

What is sedimentology?

Answer 1

study of modern sediments such as sand, silt, and clay, and the processes that result in their formation, transport, deposition and diagenesis

Question 2

What is controlling the growth rate of microscopic organisms in surface water and thus their deposition?

Answer 2

narrow ranges in sea-salinity and temperature

Question 3

What is alluvial deposition?

Answer 3

loose clay, sand, silt or gravel that has been deposited by running water

Question 4

What is fluvial deposition?

Answer 4

sediments deposited by a moving river of stream

reference: https://www.nps.gov/subjects/geology/fluvial-landforms.htm#:~:text=Fluvial%20deposits%20are%20sediments%20deposited%20by%20the%20flowing%20water%20of%20a%20stream.

Question 5

What is aoelian deposition?

Answer 5

erosions, transportation and deposition of sediment by wind

Reference: https://www.nps.gov/subjects/geology/aeolian-landforms.htm#:~:text=Aeolian%20processes%20involve%20erosion%2C%20transportation,hot%20deserts%2C%20and%20agricultural%20fields. (paraphrased)

Question 6

Where does sedimentation occur?

Answer 6

on land and in the seas

Question 7

What is the name for the collection of processes involved in sedimentology?

Answer 7

Sedimentary systmes

Question 8

What do the sedimenrary systems need to be like in relation to one another?

Answer 8

always adjacent

Question 9

What is the general trend with sedimentology?

Answer 9

Sediment will move from land (upland) to oceans via fluxes

Question 10

What is a flux?

Answer 10

a movement of matter or energy from one store to another

Question 11

What do narrow environmental conditions control with ocean sedimentology?

Answer 11

where certain sediments can occur

Question 12

How is an alluvial fan created?

Answer 12

When sediment has flowed down a valley which has stopped reducing constriction and allowing sediment to spread out laterally

Question 13

What can cause a build up of alluvial sediment?

Answer 13

freeze thaw which weakens rock

Question 14

What will sediment distribution be like for an alluvial deposit?

Answer 14

thick closer to valley thinner further away as energy available to carry material dissipates

Question 15

Where can a contrast be seen between grain size in fluvial systems?

Answer 15

in the river
out on the immediate bank

Question 16

What is the erosive power of a fluvial system?

Answer 16

high erosive power especially on outer bend

Question 17

What are aeolian systems?

Answer 17

desert systems

Question 18

What are deserts defined by?

Answer 18

aridity (dryness)

Question 19

What will grain size distribution be like in an aeolian environment?

Answer 19

uniform

Question 20

what is the are the processes for grain movement in aeolian environments?

Answer 20

constant blowing wind causing continual material processing

Question 21

What are interdune areas?

Answer 21

areas of water pooling in-between dunes

Question 22

How do wind conditions create a homogony of grain sizes?

Answer 22

fine material is blown away as cant handle wind and coarse material is buried

Question 23

What is the architecture of a sand dune like? (wind blown)

Answer 23

Bed form
Twisty crest
Asymmetrical (steep one side gentle the other)

Question 24

How will the ice and rock interact in a glacial environment?

Answer 24

The ice will be overlying the bedrock

Question 25

What general way material is weathered/ broken down in glacial systems?

Answer 25

Physical pressure (dragging) Pulling (Plucking)

Question 26

What is sediment distribution rate like for a glacial system?

Answer 26

relatively slow with poorly sorted deposits

Question 27

What sub-environment for deposition will be present in a glacial system?

Answer 27

glacial meltwater lake which might have seasonal deposition variation (Varves)

Question 28

What are deltaic areas like?

Answer 28

Low lying Varying magnitude of rivers cut through Unconstrained lateral environment

Question 29

What is the main threat towards deltaic system?

Answer 29

sea level rise

Question 30

What processes at the interface of a deltaic system help mixing of land and sea systems?

Answer 30

Tides Waves

Question 31

How do coasts act as an interface between land and sea sediment systems?

Answer 31

Can be deltaic or non-deltaic

Question 32

Why is it hard for material to break the energy fence from fluvial to marine?

Answer 32

due to high energy marine processes like waves and tides

Question 33

What might happen to sediment when it reaches a coastal system?

Answer 33

Rivers become wider form estuary and lose energy leading to deposition (spits and bars)

Question 34

What can the scale of shelfal sediment systems be?

Answer 34

hundreds of km

Question 35

What does the vast size of shelfal systems means for the sediment deposited?

Answer 35

highly variable due to changes in conditions which might be broken up by submarine channels

Question 36

How mobile is the sediment in shelfal sediment systems?

Answer 36

Static only really being disturbed by strong storms

Question 37

How do reefs affect sediment deposition?

Answer 37

complex rigid structure reduces wave energy

Question 38

What are some examples of "the giants" for sedimentary systems?

Answer 38

Glacial lake Agassiz Brahmaputra River Basin Boreal ocean delta

Question 39

What was lake Agassiz?

Answer 39

3000-4000 years old Pleistocene constrained by glaciers 440,000km*2

Question 40

What is the general info on Brahmaputra River Basin?

Answer 40

Basin plane encompassing Ganges delta 651,334km*2 9th largest river in world 2900km long

Question 41

What is the general information on the Boreal ocean delta?

Answer 41

Triassic age North Pangea emptied into shallow basin Growth through 1 million year monsoonal climate

Question 42

How large was the boreal ocean delta?

Answer 42

1,650,000km*2 1% of earth

Question 43

Are sediments static?

Answer 43

No they change through time (Wilson cycle/ plate tectonics)

Question 44

How can sea level change affect the sediment cycles?

Answer 44

change shape and extent of marine to land contact

Question 45

What are the 3 sea level orders?

Answer 45

1) 100s million years , 100s meters 2) 10s million years , 100s meters 3) 1-10 million years , 10s meters

Question 46

What can the hierarchy of sea level orders be called?

Answer 46

nested hierarchy

Question 47

How does sea