Sediment Gravity Flow Flashcards

Flashcards covering key vocabulary and concepts related to sediment gravity flows, turbidity currents, and associated sedimentary structures.

Turbidity Currents

Gravity flows in which sediment is supported by upward turbulence of the fluid within the flow.

Location of Occurence Turbidity Current

Areas where sediment is accumulating subaqueously near a slope, allowing it to mix with water and flow turbulently.

Conditioning Factors

Influential in shelf environments, including fluid dynamics, basin physiography, latitude, climatic conditions, and clastic input.

Turbidity Current

A current resulting from sediment mixing with water at a tremendous speed

Turbidity Currents Composition

Deposit a wide range of sediment types and sedimentary structures based on concentration and grain size.

Turbidity Currents Sediment Size 1

Mud and fine to medium sands

Turbidity Currents Sediment Size 2

Coarse sands to small pebbles

Turbidity Currents Sediment Size 3

Pebbles to cobbles.

Low Density Turbidity Current

Sediment concentration is < 20%. Can transport and deposit clay, silt, and sand.

Low Density Turbidity Currents Deposition

Initial deposits are coarsest particles, followed by finer particles as flow velocity decreases, and final deposition under suspension.

Laminated Mud Interpretation

Pelagic sedimentation or fine-grained, low-density turbidity current deposition.

High Density Turbidity Currents

Sediment concentration is > 20%. Can transport and support grains larger than sand.

High Density Turbidity Currents Deposit

Sandy and gravelly.

Inverse Graded Bedding

Formed during traction carpet deposition due to dispersive pressure.

Normal Graded Bed

Forms from suspension deposition as velocity drops.

Facies A Characteristics

Thick to massive, channeled and amalgamated, poorly sorted coarse Ss and Cgl, with thin or no mud intervals.

Grain Flow Deposit Structures

Exhibits sedimentary structures including grain orientation parallel to flow, scours, injection structures, and reverse grading near the base.

Debris Flow

A sedimentary deposit characterized by poor sorting, random fabric, and the possible presence of a 'coarse tail'.