C1_Coastal_systems_general.pdf

53
Gary Nichols Coastal 1 - 1 Coastal plain estuary delta: how the balance between sediment supply and accommodation determines the nature of deposits at the continental to marine interface.

Transcript of C1_Coastal_systems_general.pdf

Gary Nichols

Coastal 1 - 1

Coastal plain – estuary – delta: how the balance

between sediment supply and accommodation

determines the nature of deposits at the continental

to marine interface.

Gary Nichols

Coastal 1 - 2

Boyd et al., 1992

Coastal depositional environments

These environments all fall within a 3D

spectrum of wave, tide and river

influences in progradational or

retrogradational settings

Gary Nichols

Coastal 1 - 3

Sediment supply < Accommodation

Wave-influenced

Coastal depositional environments

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Coastal 1 - 4

Sediment supply < Accommodation

Tide-influenced

Coastal depositional environments

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Coastal 1 - 5

Accommodation < Sediment supply

Wave-influenced

Coastal depositional environments

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Coastal 1 - 6

Accommodation < Sediment supply

Tide-influenced

Coastal depositional environments

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Coastal 1 - 7

Fluvial sediment supply

Coastal depositional environments

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Coastal 1 - 8

No fluvial sediment supply

Wave-influenced

Coastal depositional environments

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Coastal 1 - 9

No fluvial sediment supply

Tide-influenced

Coastal depositional environments

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Coastal 1 - 10

Wave-dominated estuaries

Beach barrier

lagoon

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Coastal 1 - 11

Beach barrier and lagoon

Wave-dominated estuaries

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Coastal 1 - 12

Sand bar at the mouth of a wave-dominated estuary

Wave-dominated estuaries

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Coastal 1 - 13

Beach barrier

Wave-dominated estuaries

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Coastal 1 - 14

Beach barrier and lagoon

Wave-dominated estuaries

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Coastal 1 - 15

Lagoon

Wave-dominated estuaries

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Coastal 1 - 16

Lagoon mudflats

Wave-dominated estuaries

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Coastal 1 - 17 Wave-dominated estuary

Beach

Estuary mouth

Central lagoon

Bay head delta

metr

es -

10s m

etr

es

Sedimentary log of a wave-dominated estuary

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Coastal 1 - 18

Tide-dominated estuaries

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Coastal 1 - 19

Land above high tide High water

Low water

Tide-dominated estuaries

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Coastal 1 - 20

FLOOD

TIDE

EBB

TIDE

Tide-dominated estuaries

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Coastal 1 - 21

Tidal channels

Tidal creeks

Mudflats

Tide-dominated estuaries

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Coastal 1 - 22

Tide-dominated estuaries

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Coastal 1 - 23

Tide-dominated estuaries

Sand deposited on bars in tidal channels

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Coastal 1 - 24

Tide-dominated estuaries

Sand deposited on bars in tidal channels

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Coastal 1 - 25

Sand deposited on bars in tidal channels

Tide-dominated estuaries

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Coastal 1 - 26

Tidal mudflats and tidal creeks Tide-dominated estuaries

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Coastal 1 - 27

Depositional settings in a tidally-dominated estuary

Tide-dominated estuaries

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Coastal 1 - 28

Upper tidal flat

Tidal creek

Lower tidal flat

Tidal channel – tidal flow

indicators

Scoured base of channel

metr

es -

10s

metr

es

Tide-dominated estuaries

A sedimentary

log of a tidal

estuary

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Coastal 1 - 29

Barriers and lagoons

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Coastal 1 - 30

Wave-dominated coastline: coastal plain and sandy beach

Barriers and lagoons

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Coastal 1 - 31

Barrier islands - beaches not attached to the coastal plain

Barriers and lagoons

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Coastal 1 - 32

Beach-barrier bar along a wave-dominated coastline

Barriers and lagoons

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Coastal 1 - 33

Barriers and lagoons

Barrier islands

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Coastal 1 - 34

Barrier islands Barriers and lagoons

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Coastal 1 - 35

Beach barrier with

lagoon (right) and

open sea (left)

Barriers and lagoons

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Coastal 1 - 36

Lagoons are low energy, shallow water behind a barrier

Barriers and lagoons

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Coastal 1 - 37

Lagoons are low energy, shallow water behind a barrier

Barriers and lagoons

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Coastal 1 - 38

Bioturbated muds

Wave rippled

washover sands

metr

es

Barriers and lagoons

A graphic

sedimentary

log of a clastic

lagoon

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Coastal 1 - 39

With mixed wave and tidal processes the barrier is breached by more inlets – ebb and flood tidal deltas

Coastal morphology

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Coastal 1 - 40

Coastal morphology Muddy shoreline on a tidally-dominated coast

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Coastal 1 - 41

Muddy lagoon in mixed wave and tidal setting

Coastal morphology

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Coastal 1 - 42

Beach dunes

Washover sands

Flood tidal delta

deposits

Lagoon

metr

es -

10s

metr

es

Coastal morphology

A graphic

sedimentary log

of a transgressive

coast

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Coastal 1 - 43

Boyd et al., 1992

Coastal depositional environments

These environments all fall within a 3D

spectrum of wave, tide and river

influences in progradational or

retrogradational settings

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Coastal 1 - 44

Variations in delta morphology and facies

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Coastal 1 - 45

River-dominated delta

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Coastal 1 - 46

Delta plain Delta channel Distributary mouth bar Delta front

10

s m

etr

es

River-dominated delta

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Wave-influenced delta

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Coastal 1 - 48

Delta plain Beach Distributary mouth bar Delta front Pro delta

10

s m

etr

es

Wave-influenced delta

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Coastal 1 - 49

Tide-influenced delta

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Tidal flats Tidal channel (mud drapes, bidirectional flow) Tidal sand bars of delta front Pro-delta

10

s m

etr

es

Tide-influenced delta

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Coastal 1 - 51

Classification of deltas

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Coastal 1 - 52 Controls on delta environments and facies

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Coastal 1 - 53

Boyd et al., 1992

Coastal depositional environments

These environments all fall within a 3D

spectrum of wave, tide and river

influences in progradational or

retrogradational settings