Sedimentary Sedimentary GeologyGeology

Geos 240 – Chapter Geos 240 – Chapter 77

Sediment Transport Sediment Transport ProcessesProcesses Dr. Tark HamiltonDr. Tark Hamilton

Readings from Sediments & Basins: (7:1-41)Readings from Sediments & Basins: (7:1-41) Camosun CollegeCamosun College

Crossbeds, Cretaceous Non-Crossbeds, Cretaceous Non-Marine NEBCMarine NEBC

Hjulstrom Diagram: Caliber vs Hjulstrom Diagram: Caliber vs VelocityVelocity

Turbulent Boundary LayerTurbulent Boundary LayerCauses Flow Separation:Causes Flow Separation:

Tractive flow, Entrainment, Tractive flow, Entrainment, SuspensionSuspension

Turbidity Current in a Lab Turbidity Current in a Lab Flume:Flume:

Dense, Turbulent, Sediment Dense, Turbulent, Sediment UnderflowUnderflow

Bedform Phase Diagram:Bedform Phase Diagram:Stable Bedforms vs Caliber & VelocityStable Bedforms vs Caliber & Velocity

2-D 2-D PlanarPlanarTabularTabularX-bedsX-beds

Platte Platte River River

NebraskaNebraska

~3.19 ~3.19 m/secm/sec

3-D3-DLinguoidLinguoid

DunesDunes&&

TroughTroughX-bedsX-beds

Flume Flume ObservationsObservations

Lam

inar

Sta

ble

Flo

w

Turb

ule

nt

Flo

w

Variation in Ripple/Dune Variation in Ripple/Dune shapesshapes

Versus Shallowness & VelocityVersus Shallowness & Velocity

or

Large simple X-bed, Devonian Old Red Sandstone. Large simple X-bed, Devonian Old Red Sandstone. ScotlandScotland

Real Gap, no bedformsUnstable turbulent transition

Gravel DunesHaro Strait

Upper Plane Bed. Platte River NebraskaUpper Plane Bed. Platte River Nebraska

Upper Plane Bed. Proterozoic siltstoneUpper Plane Bed. Proterozoic siltstone

Upper Plane Bed. Ordovician calcarenite. Bed Upper Plane Bed. Ordovician calcarenite. Bed bottom & scourbottom & scour

Standing Waves form Standing Waves form AntidunesAntidunes

Alaska

Standing Waves form Standing Waves form AntidunesAntidunes

California Beach

Climbing RipplesClimbing Ripples

Climbing RipplesClimbing Ripples

Climbing RipplesClimbing Ripples

Planar Cross BedsPlanar Cross Beds

Planar Cross BedsPlanar Cross Beds

Trough Cross BedsTrough Cross Beds

Trough Cross BedsTrough Cross Beds

Gravel Bar Bedforms, Modern Gravel Bar Bedforms, Modern RiverRiver

Gravel Bar Bedforms, Modern Gravel Bar Bedforms, Modern RiverRiver

Imbrication of ClastsImbrication of Clasts

ReversingReversingTidal Tidal

CurrentsCurrentsFloodFlood

SlackwaterSlackwaterEbbEbb

SlackwaterSlackwater

**(not all tides (not all tides areare

purely diurnal!)purely diurnal!)~basin shape~basin shape

Symmetric - Tidal Foresets - Symmetric - Tidal Foresets - AsymmetricAsymmetric

Or Tidal Delta

New/Full Half

Tidal Bedding TerminologyTidal Bedding Terminology

Tidal Ripple Bedforms, Seattle Tidal Ripple Bedforms, Seattle WAWA

Wavy Bedding, Cretaceous, Wavy Bedding, Cretaceous, UtahUtah

Bedform Type versus Location Bedform Type versus Location with Waveswith Waves

Waves in Shallows, Near ShoreWaves in Shallows, Near Shore

Wave Rippled Modern Beach Wave Rippled Modern Beach South CarolinaSouth Carolina

Interference Patterns in Sandy RipplesInterference Patterns in Sandy RipplesFormed During Prior Flood TideFormed During Prior Flood Tide

Being Modified in EbbBeing Modified in Ebb

Wave Rippled Ordovician Calcarenites, Wave Rippled Ordovician Calcarenites, OttawaOttawa

Sandbars

Herringbone

Calsiltites

Dolo-grainstones

HummockHummockyy

CrossCrossStratificatStratificat

ionion(HCS)(HCS)

JurassicJurassicOld RedOld Red

SandstonSandstonee

YorkshireYorkshire(domes &(domes &mounds)mounds)

Storm Driven – Coriolis Storm Driven – Coriolis ControlledControlled

Due to Flow in a Rotating Due to Flow in a Rotating Reference FrameReference Frame

4 Types of Dunes in Eolian 4 Types of Dunes in Eolian SettingsSettings

Dreat Sand Dunes Nat’l Dreat Sand Dunes Nat’l Monument, COMonument, CO

Transverse Dunes, Gobi Transverse Dunes, Gobi Desert, ChinaDesert, China

Transverse Dunes, Gobi Transverse Dunes, Gobi Desert, ChinaDesert, China

Barchan Dunes, Gobi Desert, Barchan Dunes, Gobi Desert, ChinaChina

Modern Wind Ripples Climbing Modern Wind Ripples Climbing Dune FaceDune Face

Lighter Winds ChannelledBy Older Dunes

Permian Wind Fall Ripples AZPermian Wind Fall Ripples AZ

Note Rare Wind Ripple Foresets

Modern Grain Fall Deposits Down Modern Grain Fall Deposits Down Dune FaceDune Face

Modern Grain Flow Lobes Down Dune Modern Grain Flow Lobes Down Dune FaceFace

Permian Permian Grain FallGrain Fall & & Grain FlowGrain Flow Lenses, UKLenses, UK

Permian Permian Grain FallGrain Fall & & Grain FlowGrain Flow Lenses, UKLenses, UK

Flow Direction out of Page & Downwards

Foresets & Ripples, Permian, Foresets & Ripples, Permian, ArizonaArizona

Wind Ripples Down Dune Face, Wind Ripples Down Dune Face, Permian, ArizonaPermian, Arizona

Classification of Sediment Classification of Sediment Gravity FlowsGravity Flows

Evolution of Flow Type with Evolution of Flow Type with TimeTime

Debris Flow, Venezuela Debris Flow, Venezuela Feb 2000Feb 2000

Cenozoic Debris FlowCenozoic Debris FlowWith Large Logs, JapanWith Large Logs, Japan

Reworked Glaciomarine Reworked Glaciomarine Debris FlowDebris Flow

Miocene Debris Flow,Miocene Debris Flow,Near Anatolian Fault TurkeyNear Anatolian Fault Turkey

Miocene Debris Flow,Miocene Debris Flow,Near Anatolian Fault TurkeyNear Anatolian Fault Turkey

Mud Ball?

Cenozoic Polymict Cenozoic Polymict Conglomerate,Conglomerate,

California (Any Faults California (Any Faults nearby?)nearby?)

Cambro-Ordovician Cow Cambro-Ordovician Cow Head Breccia, W. Head Breccia, W.

NewfoundlandNewfoundland

Reef Breccia

Abyssal Turbidites

Cambro-Ordovician Cow Cambro-Ordovician Cow Head Breccia, W. Head Breccia, W.

NewfoundlandNewfoundland

Reef Breccia

Remoulded Turbidites

Cretaceous Debris Flow Lenses Cretaceous Debris Flow Lenses FranceFrance

Tethyan Reef Debris

Sediment Gravity Flows & Sediment Gravity Flows & SupportSupport

See Notes

Fluidized Flows, Cretaceous S. Fluidized Flows, Cretaceous S. FranceFrance

Fluidized Flows, Cenozoic Fluidized Flows, Cenozoic Riverdale CARiverdale CA

Dense, Cold, Sediment LadenDense, Cold, Sediment LadenGlacial Outwash Plunges Glacial Outwash Plunges

BeneathBeneathLake Louise AB as a Turbidity Lake Louise AB as a Turbidity

CurrentCurrentSee Notes

7.2 7.2 QuakeQuake~20 ~20 kmkm

deepdeepTsunaTsuna

mimisweptsweptBurin Burin PeninsPenins

ulaula

1929 Grand Banks Failure & 1929 Grand Banks Failure & TsunamiTsunami

1929 Grand 1929 Grand Banks FailureBanks FailureTriggered by Triggered by EarthquakeEarthquake

(Each Lat° is 60 (Each Lat° is 60 nm)nm)

This Puppy This Puppy Travelled 1353 Travelled 1353

km!km!

Complete Bouma Sequence Complete Bouma Sequence (Medial)(Medial)

Tu

rbid

ity

Eve

nt

Pela

gic

Sed

imen

t

Down Current &Along Transport

Evolution ofTurbidites

Medial Deposits: B >> CDistal D & E CoupletsProximal Deposits: A > B-E