Flow Regimes, Erosion Regimes, and other Sedimentary Structures

Other ways to describe low energy system

Low velocity, distal

Other ways to describe high energy systems

High velocity, proximal

Sand ripples in lower-lower flow regime

Small straight crested ripples, linguloid ripples

Sand ripples in upper-lower flow regime

Large straight crested ripples, lunate ripple

Cross laminations in lower-lower flow regimes

Small planar cross beds, small trough cross beds

Cross beds found in upper-lower flow regimes

Large planar cross beds, large trough cross beds

Lunate ripples form what crossbeds?

Large trough cross beds

Large straight crested ripples form what crossbeds?

Large planar cross beds

Small straight crested ripples form what crossbeds?

Small planar cross beds

Linguloid ripples for what kind of crossbed?

Small trough cross beds

Bed forms from upper flow regimes?

Plane beds, anti-dunes, chute and pool

Bed forms in no deposition/erosion regimes?

Flute/Tool Marks, scours, channels

Internal structures in no deposition/erosion regimes?

Sediment channel fill

List Flow Separation Zones in order (top to bottom ).

Zone of no diffusion, zone of diffusion, zone of backflow. 

What kind of ripples are these? What flow regimes do they form in?

Small straight crested ripples, Lower-lower flow regimes

What kind of ripples are these? What flow regimes do they form in?

Linguloid ripples, lower-lower flow regimes

What kind of ripples are these? What flow regimes do they form in?

Large straight crested ripples, upper-lower regimes

What kind of ripples are these? What flow regimes do they form in?

Lunate ripples, upper-lower flow regime

What kind of cross beds are these? What ripples do they form from?

Small planar cross beds, Small straight crested ripples

What kind of cross beds are these? What ripples do they form from?

Small trough cross beds, linguloid ripples

What kind of cross beds are these? What ripples do they form from?

Large planar cross beds, large straight crested ripples

What kind of cross beds are these? What ripples do they form from?

Large trough cross beds, lunate ripples

Name, in order, all of these upper flow regime ripples. 

Plane bed, anti-dunes, chute & pools

What are these?

Flute marks

Very low energy flow, undetectable, doesn’t show up in geological timescales.

Laminar flow

As energy picks up this forms; once it touches the bottom of a bed it picks up sediment and erodes it. Forms troughs

Scouring Vortex/Eddie

The upstream facing side of a crest.

Stoss

The downstream facing side of a crest.

Lee/Slip face

Water ripples match sand ripples, sand grains move together in a ‘haze’ forming flat laminations parallel to the water

High Velocity Laminations/Plane Beds

Extremely high velocity (can’t stand in), form curved laminations matching the waves. 

Antidunes

Not all in phase with each other, large volume of water on one side with a small body on the other side — velocity increases as the large body of water flows into the small body of water, causes upstream wave breaks. 

Chute & Pool

Rocks get picked up in rapid floods and move down stream quickly, forms point bars and cut banks. 

Scours & channels

Formed by rip currents. 

Shelf Scours/Gutters

Carves made into laminations

Scours

Made by an avalanche of sand when it’s disturbed at criticality, flowing down a slope. Scours into the previous sediment base, with sand filling that scour. 

Flute Marks

Marks indicating that something something was being carried through the water. 

Groove Marks

Water only flowing in one direction on terrestrial planes. 

Unidirectional Flow

Energy of the water changes (ie. waves going back and forth). 

Oscillatory Flow

When two different directions of energy change the way the water flows. 

Combination Flow

What kind of flow do these waves follow?

Pure oscillatory flow

Waves that are symmetrical, can be found in pure oscillatory ripples. Sand ripples match these (2).

Stokes waves, sinusodal

Bundles of thickening and thinning stratifications, the bundles cutting into each other. The surface has small domes and swales. Forms in storm shelf environments.

Hummocky cross stratification