sedimentary facies

59
GEOL 553 Lecture 3; Subsurface Analysis GEOL 553: GEOL 553: Marine Sediments Marine Sediments University of South Carolina University of South Carolina Fall 2005 Fall 2005 Professor Chris Kendall Professor Chris Kendall EWS 304 EWS 304 [email protected] [email protected] 777.2410 777.2410 Tools of Subsurface Analy Tools of Subsurface Analy

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Sedimentary Facies

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Page 1: Sedimentary Facies

GEOL 553 Lecture 3; Subsurface Analysis

GEOL 553: GEOL 553: Marine SedimentsMarine SedimentsUniversity of South CarolinaUniversity of South Carolina

Fall 2005Fall 2005

Professor Chris KendallProfessor Chris KendallEWS 304 EWS 304

[email protected] [email protected] 777.2410777.2410

The Tools of Subsurface AnalysisThe Tools of Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

The Tools of Subsurface The Tools of Subsurface AnalysisAnalysis

The Tools of Subsurface The Tools of Subsurface AnalysisAnalysis

Well logsWell logs Cores Cores SeismicSeismic Gravity & Gravity &

magneticsmagnetics

Facies analysis of subsurface Facies analysis of subsurface data depends on tools which data depends on tools which delimit of surfaces and provide delimit of surfaces and provide clues as to the sediments they clues as to the sediments they contain:contain:

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GEOL 553 Lecture 3; Subsurface Analysis

Well Logs Versus SeismicWell Logs Versus SeismicWell Logs Versus SeismicWell Logs Versus Seismic Well logs Well logs

Great vertical resolution Great vertical resolution Delimit bounding surfacesDelimit bounding surfacesEstablish lithology of sediments Establish lithology of sediments

penetratedpenetrated SeismicSeismic

Great lateral continuity and Great lateral continuity and resolutionresolution

Define gross sediment geometryDefine gross sediment geometry

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GEOL 553 Lecture 3; Subsurface Analysis

Tools are Keys to Allostratigraphy &

Sequence Stratigraphy

Tools are Keys to Allostratigraphy &

Sequence Stratigraphy AllostratigraphyAllostratigraphy: bounding discontinuities : bounding discontinuities

including erosion surfaces, marine including erosion surfaces, marine flooding surfaces, tuffs, tempestite, flooding surfaces, tuffs, tempestite, and/or turbidite boundaries etc. as time and/or turbidite boundaries etc. as time markersmarkers

Sequence StratigraphySequence Stratigraphy: higher level : higher level allostratigraphic model which interprets allostratigraphic model which interprets depositional origin of sedimentary strata depositional origin of sedimentary strata as products of "relative sea level change"as products of "relative sea level change"

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GEOL 553 Lecture 3; Subsurface Analysis

The Tools of Subsurface Analysis

The Tools of Subsurface Analysis

Well logsWell logs SeismicSeismic

Facies analysis of subsurface Facies analysis of subsurface data depends on tools which data depends on tools which delimit of surfaces and provide delimit of surfaces and provide clues as to the sediments they clues as to the sediments they contain:contain:

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GEOL 553 Lecture 3; Subsurface Analysis

Well LogsWell Logs

Resistivity LogsResistivity Logs Spontaneous Potential (SP) LogsSpontaneous Potential (SP) Logs Gamma Ray LogsGamma Ray Logs Neutron LogsNeutron Logs Density LogsDensity Logs Sonic (acoustic) LogsSonic (acoustic) Logs

Delimit of surfaces & identify sediments Delimit of surfaces & identify sediments penetratedpenetrated

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

Resistivity LogsResistivity Logs

Measures resistance of flow of Measures resistance of flow of electric currentelectric current

Is function of porosity & pore fluid Is function of porosity & pore fluid in rockin rock

Frequently used to identify Frequently used to identify lithologylithology

The most commonly used The most commonly used logs:logs:

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

Spontaneous Potential (SP) Logs

Spontaneous Potential (SP) Logs

Measures electrical current in wellMeasures electrical current in well Result of salinity differences Result of salinity differences

between formation water and the between formation water and the borehole mudborehole mud

Separates bed boundaries of Separates bed boundaries of permeable sands & impermeable permeable sands & impermeable shales.shales.

Next most common Next most common loglog

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

Gamma Ray LogsGamma Ray Logs

Records radioactivity of a formationRecords radioactivity of a formation Shales have high gamma radioactive Shales have high gamma radioactive

responseresponse Gamma ray logs infer grain size (and Gamma ray logs infer grain size (and

so subsequently inferred depositional so subsequently inferred depositional energy)energy)

Gamma ray logs are most commonly Gamma ray logs are most commonly used logs for sequence stratigraphic used logs for sequence stratigraphic analysisanalysis

Another common logAnother common log

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface AnalysisAfter Harris & Saller 1999

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GEOL 553 Lecture 3; Subsurface Analysis

Neutron LogsNeutron Logs

Measures porosity of formationMeasures porosity of formation Uses quantity of hydrogen presentUses quantity of hydrogen present Measures lithology when used with Measures lithology when used with

Density LogDensity Log

Another common Another common loglog

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GEOL 553 Lecture 3; Subsurface Analysis

Density LogsDensity Logs

Measures formation’s bulk densityMeasures formation’s bulk density Used as a porosity measureUsed as a porosity measure Differentiates lithologies with Differentiates lithologies with

Neutron LogNeutron Log Used with Sonic Logs to generate Used with Sonic Logs to generate

synthetic seismic traces to match synthetic seismic traces to match to seismic linesto seismic lines

A common logA common log

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GEOL 553 Lecture 3; Subsurface Analysis

Sonic (Acoustic) LogsSonic (Acoustic) Logs

Measures of speed of sound in Measures of speed of sound in formationformation

Tied to porosity and lithologyTied to porosity and lithology Used with Density Logs to Used with Density Logs to

generate Synthetic Seismic traces generate Synthetic Seismic traces to match to Seismic linesto match to Seismic lines

Another common logAnother common log

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

Page 22: Sedimentary Facies

GEOL 553 Lecture 3; Subsurface Analysis

The Tools of Subsurface Analysis

The Tools of Subsurface Analysis

Well logsWell logs SeismicSeismic

Facies analysis of subsurface Facies analysis of subsurface data depends on tools which data depends on tools which delimit of surfaces and provide delimit of surfaces and provide clues as to the sediments they clues as to the sediments they contain:contain:

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GEOL 553 Lecture 3; Subsurface Analysis

SeismicSeismic

Define geometries of genetic Define geometries of genetic reflection packages that envelope reflection packages that envelope seismic sequences and systems seismic sequences and systems tractstracts

Identify bounding discontinuities Identify bounding discontinuities on basis of reflection termination on basis of reflection termination patterns and continuitypatterns and continuity

Seismic stratigraphic Seismic stratigraphic interpretation used to:interpretation used to:

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GEOL 553 Lecture 3; Subsurface Analysis

Seismic BoundariesSeismic Boundaries

Toplap termination Toplap termination Truncation of sediment surface Truncation of sediment surface Often channel bottomOften channel bottom

Termination below discontinuity, Termination below discontinuity, or upper sequence boundaryor upper sequence boundary ::

Onlap over surfaceOnlap over surface Downlap surfaceDownlap surface

Above a discontinuity defining Above a discontinuity defining lower sequence boundary:lower sequence boundary:

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GEOL 553 Lecture 3; Subsurface Analysis

Seismic BoundariesSeismic Boundaries

Below Boundary - Toplap terminationBelow Boundary - Toplap termination

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GEOL 553 Lecture 3; Subsurface Analysis

Seismic BoundariesSeismic Boundaries

Below Boundary -Below Boundary - Truncation of Truncation of surfacesurface

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GEOL 553 Lecture 3; Subsurface Analysis

Seismic BoundariesSeismic Boundaries

ChanneledChanneled

Surface Surface

– – Below Below BoundaryBoundary

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GEOL 553 Lecture 3; Subsurface Analysis

Seismic BoundariesSeismic BoundariesOver Boundary - Onlap onto surfaceOver Boundary - Onlap onto surface

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GEOL 553 Lecture 3; Subsurface Analysis

Seismic BoundariesSeismic BoundariesOver Boundary- Downlap onto Over Boundary- Downlap onto

surfacesurface

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

Sequence StratigraphySequence Stratigraphy

Surfaces of erosion & non-deposition Surfaces of erosion & non-deposition (sequence boundaries)(sequence boundaries)

Flooding (trangressive surfaces [TS] &/or Flooding (trangressive surfaces [TS] &/or maximum flooding surfaces [mfs]) & high maximum flooding surfaces [mfs]) & high stand condensed surfacesstand condensed surfaces

Subdivision & interpretation of Subdivision & interpretation of sedimentary record using a framework sedimentary record using a framework surfaces seen in outcrops, surfaces seen in outcrops, well logs, & 2-well logs, & 2-D and 3-D seismicD and 3-D seismic. . Include:Include:

This framework used to predict the This framework used to predict the extent of sedimentary facies extent of sedimentary facies geometry, lithologic character, geometry, lithologic character, grain size, sorting & reservoir grain size, sorting & reservoir qualityquality

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GEOL 553 Lecture 3; Subsurface Analysis

Tools Define Bounding Surfaces Tools Define Bounding Surfaces

Relative time framework for sedimentary Relative time framework for sedimentary successionsuccession

Better understanding of inter-Better understanding of inter-relationship of depositional settings & relationship of depositional settings & their lateral correlationtheir lateral correlation

These surfaces subdivide These surfaces subdivide sedimentary rocksedimentary rock &provide:-provide:-

Conceptual models follow that link the processes that formed the sediments and enable the prediction of their gross geometries

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GEOL 553 Lecture 3; Subsurface Analysis

Sequence geometries are subdivided and Sequence geometries are subdivided and defined bydefined by

Maximum Flooding Surfaces (mfs) Maximum Flooding Surfaces (mfs) Transgressive Surfaces (TS) Transgressive Surfaces (TS) Sequence Boundaries (SB)Sequence Boundaries (SB)

Define how vertical succession or stacking Define how vertical succession or stacking patterns of unconfined sheets are arranged patterns of unconfined sheets are arranged

Prograde (step seaward) Prograde (step seaward) Retrograde (step landward) Retrograde (step landward) Aggrade (build vertically)Aggrade (build vertically)

Sheets and unconfined lobes may containSheets and unconfined lobes may containNon-amalgamated bodiesNon-amalgamated bodies

Amalgamated, multi-storied bodiesAmalgamated, multi-storied bodiesIncised topographic fill of valleysIncised topographic fill of valleysUnconfined but localized lobes from point & Unconfined but localized lobes from point & multiple up dip sourcesmultiple up dip sourcesUnconfined but localized build ups (carbonates)Unconfined but localized build ups (carbonates)

Hierarchy of GeometriesHierarchy of Geometries

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GEOL 553 Lecture 3; Subsurface Analysis

Page 38: Sedimentary Facies

GEOL 553 Lecture 3; Subsurface Analysis

Sequence geometries are subdivided and Sequence geometries are subdivided and defined bydefined by

Maximum Flooding Surfaces (mfs) Maximum Flooding Surfaces (mfs) Transgressive Surfaces (TS) Transgressive Surfaces (TS) Sequence Boundaries (SB)Sequence Boundaries (SB)

Define how vertical succession or stacking Define how vertical succession or stacking patterns of unconfined sheets are arranged patterns of unconfined sheets are arranged

Prograde (step seaward) Prograde (step seaward) Retrograde (step landward) Retrograde (step landward) Aggrade (build vertically)Aggrade (build vertically)

Sheets and unconfined lobes may containSheets and unconfined lobes may containNon-amalgamated bodiesNon-amalgamated bodies

Amalgamated, multi-storied bodiesAmalgamated, multi-storied bodiesIncised topographic fill of valleysIncised topographic fill of valleysUnconfined but localized lobes from point & Unconfined but localized lobes from point & multiple up dip sourcesmultiple up dip sourcesUnconfined but localized build ups (carbonates)Unconfined but localized build ups (carbonates)

Hierarchy of GeometriesHierarchy of Geometries

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GEOL 553 Lecture 3; Subsurface Analysis

Page 40: Sedimentary Facies

GEOL 553 Lecture 3; Subsurface Analysis

Sequence geometries are subdivided and Sequence geometries are subdivided and defined bydefined by

Maximum Flooding Surfaces (mfs) Maximum Flooding Surfaces (mfs) Transgressive Surfaces (TS) Transgressive Surfaces (TS) Sequence Boundaries (SB)Sequence Boundaries (SB)

Define how vertical succession or stacking Define how vertical succession or stacking patterns of unconfined sheets are arranged patterns of unconfined sheets are arranged

Prograde (step seaward) Prograde (step seaward) Retrograde (step landward) Retrograde (step landward) Aggrade (build vertically)Aggrade (build vertically)

Sheets and unconfined lobes may containSheets and unconfined lobes may containNon-amalgamated bodiesNon-amalgamated bodies

Amalgamated, multi-storied bodiesAmalgamated, multi-storied bodiesIncised topographic fill of valleysIncised topographic fill of valleysUnconfined but localized lobes from point & Unconfined but localized lobes from point & multiple up dip sourcesmultiple up dip sourcesUnconfined but localized build ups (carbonates)Unconfined but localized build ups (carbonates)

Hierarchy of GeometriesHierarchy of Geometries

Page 41: Sedimentary Facies

GEOL 553 Lecture 3; Subsurface Analysis

Page 42: Sedimentary Facies

GEOL 553 Lecture 3; Subsurface Analysis

Sequence geometries are subdivided and Sequence geometries are subdivided and defined bydefined by

Maximum Flooding Surfaces (mfs) Maximum Flooding Surfaces (mfs) Transgressive Surfaces (TS) Transgressive Surfaces (TS) Sequence Boundaries (SB)Sequence Boundaries (SB)

Define how vertical succession or stacking Define how vertical succession or stacking patterns of unconfined sheets are arranged patterns of unconfined sheets are arranged

Prograde (step seaward) Prograde (step seaward) Retrograde (step landward) Retrograde (step landward) Aggrade (build vertically)Aggrade (build vertically)

Sheets and unconfined lobes may containSheets and unconfined lobes may containNon-amalgamated bodiesNon-amalgamated bodies

Amalgamated, multi-storied bodiesAmalgamated, multi-storied bodiesIncised topographic fill of valleysIncised topographic fill of valleysUnconfined but localized lobes from point & Unconfined but localized lobes from point & multiple up dip sourcesmultiple up dip sourcesUnconfined but localized build ups (carbonates)Unconfined but localized build ups (carbonates)

Hierarchy of GeometriesHierarchy of Geometries

Page 43: Sedimentary Facies

GEOL 553 Lecture 3; Subsurface Analysis

Page 44: Sedimentary Facies

GEOL 553 Lecture 3; Subsurface Analysis

Sequence geometries are subdivided and Sequence geometries are subdivided and defined bydefined by

Maximum Flooding Surfaces (mfs) Maximum Flooding Surfaces (mfs) Transgressive Surfaces (TS) Transgressive Surfaces (TS) Sequence Boundaries (SB)Sequence Boundaries (SB)

Define how vertical succession or stacking Define how vertical succession or stacking patterns of unconfined sheets are arranged patterns of unconfined sheets are arranged

Prograde (step seaward) Prograde (step seaward) Retrograde (step landward) Retrograde (step landward) Aggrade (build vertically)Aggrade (build vertically)

Sheets and unconfined lobes may containSheets and unconfined lobes may containNon-amalgamated bodiesNon-amalgamated bodies

Amalgamated, multi-storied bodiesAmalgamated, multi-storied bodiesIncised topographic fill of valleysIncised topographic fill of valleysUnconfined but localized lobes from point & Unconfined but localized lobes from point & multiple up dip sourcesmultiple up dip sourcesUnconfined but localized build ups (carbonates)Unconfined but localized build ups (carbonates)

Hierarchy of GeometriesHierarchy of Geometries

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GEOL 553 Lecture 3; Subsurface Analysis

Ebb Ooid Delta - UAEEbb Ooid Delta - UAE

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GEOL 553 Lecture 3; Subsurface Analysis

Delta Mouth Bar - Kentucky

Delta Mouth Bar - Kentucky

Note Incised SurfaceNote Incised Surface

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GEOL 553 Lecture 3; Subsurface Analysis

Channel – Gulf CoastChannel – Gulf Coast

Note Incised SurfaceNote Incised Surface

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GEOL 553 Lecture 3; Subsurface Analysis

Flood Deltas & Channels - Kty

Flood Deltas & Channels - Kty

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GEOL 553 Lecture 3; Subsurface Analysis

TidalChannel

sKhor

alBazam

-UAE

TidalChannel

sKhor

alBazam

-UAE

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GEOL 553 Lecture 3; Subsurface Analysis

Tidal, Storm or Tsunami Channel

Tidal, Storm or Tsunami Channel

Note Incised SurfaceNote Incised Surface

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GEOL 553 Lecture 3; Subsurface Analysis

Tsunami Load & Drape - Kty

Tsunami Load & Drape - Kty

Note Uniform Thickness of LayerNote Uniform Thickness of Layer

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GEOL 553 Lecture 3; Subsurface Analysis

Clastic Sequence Stratigraphic Hierarchies

Clastic Sequence Stratigraphic Hierarchies

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GEOL 553 Lecture 3; Subsurface Analysis

Channels & Shelves Channels & Shelves

Chann

el

Chann

elShelfShelf

Both have unique Both have unique processes & structures that processes & structures that

can be used to identify can be used to identify their settingtheir setting

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GEOL 553 Lecture 3; Subsurface Analysis

Tools Enable Sequence Stratigraphic Analysis

Tools Enable Sequence Stratigraphic Analysis

Subdivision of section into sequences, Subdivision of section into sequences, parasequences and beds.parasequences and beds.

Link conceptual models with mix of Link conceptual models with mix of components of the individual sequence, components of the individual sequence, parasequence or beds parasequence or beds

Use these to explain the depositional Use these to explain the depositional setting in terms of their lithology, grain setting in terms of their lithology, grain size, sedimentary structures, contacts size, sedimentary structures, contacts character (gradational, abrupt) etccharacter (gradational, abrupt) etc

This analysis involvesThis analysis involves

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GEOL 553 Lecture 3; Subsurface Analysis

SequenceStratigraphi

cAnalysis

SequenceStratigraphi

cAnalysis

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End of the LectureEnd of the Lecture

Can it be supper Can it be supper time?time?

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

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GEOL 553 Lecture 3; Subsurface Analysis

Unconfined Flow - Not in a ChannelUnconfined Flow - Not in a Channel Unique ProcessesUnique Processes

Flow is in all directions Flow is in all directions No lateral boundaries, only upper and lower No lateral boundaries, only upper and lower boundaries boundaries Velocity changes: high to low Velocity changes: high to low

Sediment responsesSediment responsesDecrease in grain size: Fining outward Decrease in grain size: Fining outward (coarse to fine)(coarse to fine)Erosional/sharp/gradational contacts Erosional/sharp/gradational contacts Accretion: Downstream, upstream and Accretion: Downstream, upstream and vertical vertical Decrease in sedimentary structures away Decrease in sedimentary structures away from source from source

GeometriesGeometriesSheets Sheets Thin in direction of flow Thin in direction of flow