Sedimentary Geology Geos 240 – Chapter 7 Sediment Transport Processes Dr. Tark Hamilton Dr. Tark Hamilton Readings from Sediments & Basins: (7:1-41) Readings from Sediments & Basins: (7:1-41) Camosun College Camosun College
Crossbeds, Cretaceous Non-Marine NEBC
Hjulstrom Diagram: Caliber vs Velocity
Turbulent Boundary Layer Causes Flow Separation: Tractive flow, Entrainment, Suspension
Turbidity Current in a Lab Flume: Dense, Turbulent, Sediment Underflow
Bedform Phase Diagram: Stable Bedforms vs Caliber & Velocity
2-D Planar Tabular X-beds Platte River Nebraska ~3.19 m/sec
3-D Linguoid Dunes & Trough X-beds
Flume Observations Laminar Stable Flow Turbulent Flow
Variation in Ripple/Dune shapes Versus Shallowness & Velocity or
Large simple X-bed, Devonian Old Red Sandstone. Scotland
Real Gap, no bedforms Unstable turbulent transition Gravel Dunes Haro Strait
Upper Plane Bed. Platte River Nebraska
Upper Plane Bed. Proterozoic siltstone
Upper Plane Bed. Ordovician calcarenite. Bed bottom & scour
Standing Waves form Antidunes Alaska
Standing Waves form Antidunes California Beach
Climbing Ripples
Planar Cross Beds
Trough Cross Beds
Gravel Bar Bedforms, Modern River
Imbrication of Clasts
Reversing Tidal Currents Flood Slackwater Ebb Slackwater * (not all tides are purely diurnal!) ~basin shape
Symmetric - Tidal Foresets - Asymmetric Or Tidal Delta
New/FullHalf
Tidal Bedding Terminology
Tidal Ripple Bedforms, Seattle WA
Wavy Bedding, Cretaceous, Utah
Bedform Type versus Location with Waves
Waves in Shallows, Near Shore
Wave Rippled Modern Beach South Carolina Interference Patterns in Sandy Ripples Formed During Prior Flood Tide Being Modified in Ebb
Wave Rippled Ordovician Calcarenites, Ottawa Sandbars Herringbone Calsiltites Dolo-grainstones
Hummocky Cross Stratification (HCS) Jurassic Old Red Sandstone Yorkshire (domes & mounds)
Storm Driven – Coriolis Controlled Due to Flow in a Rotating Reference Frame
4 Types of Dunes in Eolian Settings
Dreat Sand Dunes Nat’l Monument, CO
Transverse Dunes, Gobi Desert, China
Barchan Dunes, Gobi Desert, China
Modern Wind Ripples Climbing Dune Face Lighter Winds Channelled By Older Dunes
Permian Wind Fall Ripples AZ Note Rare Wind Ripple Foresets
Modern Grain Fall Deposits Down Dune Face
Modern Grain Flow Lobes Down Dune Face
Permian Grain Fall & Grain Flow Lenses, UK
Flow Direction out of Page & Downwards
Foresets & Ripples, Permian, Arizona
Wind Ripples Down Dune Face, Permian, Arizona
Classification of Sediment Gravity Flows
Evolution of Flow Type with Time
Debris Flow, Venezuela Feb 2000
Cenozoic Debris Flow With Large Logs, Japan
Reworked Glaciomarine Debris Flow
Miocene Debris Flow, Near Anatolian Fault Turkey
Mud Ball?
Cenozoic Polymict Conglomerate, California (Any Faults nearby?)
Cambro-Ordovician Cow Head Breccia, W. Newfoundland Reef Breccia Abyssal Turbidites
Cambro-Ordovician Cow Head Breccia, W. Newfoundland Reef Breccia Remoulded Turbidites
Cretaceous Debris Flow Lenses France Tethyan Reef Debris
Sediment Gravity Flows & Support
See Notes
Fluidized Flows, Cretaceous S. France
Fluidized Flows, Cenozoic Riverdale CA
Dense, Cold, Sediment Laden Glacial Outwash Plunges Beneath Lake Louise AB as a Turbidity Current See Notes
7.2 Quake ~20 km deep Tsunami swept Burin Peninsula
1929 Grand Banks Failure & Tsunami
1929 Grand Banks Failure Triggered by Earthquake (Each Lat° is 60 nm) This Puppy Travelled 1353 km!
Complete Bouma Sequence (Medial) Turbidity Event Pelagic Sediment
Down Current & Along Transport Evolution of Turbidites Medial Deposits: B >> CDistal D & E CoupletsProximal Deposits: A > B-E