sed exam questions &
answers
Allogenic forcing - ANSWERSControls external to the depositional system. Examples: climate
change, tectonics, sea-level
Subsidence - ANSWERSPhysical sinking of Earth's crust
Isostasy - ANSWERSThe balancing of the downward force of the crust and the upward force of
the mantle.
Provenance - ANSWERSplace or source of origin of sediment
PHI SCALE - ANSWERSExpresses grain size on a logarithmic scale. Phi values increase
arithmetically as the grain size decreases geometrically.
fissility - ANSWERSThe property of splitting easily into thin layers along closely spaced, parallel
surfaces, such as bedding planes in shale.
Ortho / Para Conglomerate - ANSWERSClast vs Matrix Supported
BED SHEAR STRESS - ANSWERSDifferential force a grain feels from bottom to top
grain reynolds number - ANSWERSIncrease means increase in grain size, shear velocity &
turbulence, or a decrease in kinematic viscosity. Measures Turbulence of a fluid.
, Froude number - ANSWERSFr; dimensionless parameter that is used as a quantitative measure
of whether sub-critical or supercritical flow will occur
Saltation - ANSWERSThe movement of sand or other sediments by short jumps and bounces
that is caused by wind or water. Type of Bedload movement.
Laminae - ANSWERSBedding planes less than 1 cm in thickness
Imbrication - ANSWERSOverlapping of elongated clasts in upstream direction
Clinoform Components - ANSWERSTopset, Foreset (Middle), Bottomset
Tabular vs Trough crossbedding - ANSWERS2D dunes vs 3D dunes (curves)
flaser, wAVY, LENTICULAR - ANSWERSripple bedding with increasing mod content
ebb, slack, flood tide - ANSWERSoutward tide, non-moving, inward tide
groove cast - ANSWERSformed by dragging pebble, wood, shells, etc. in flow
flute casts - ANSWERSU-shaped imprints formed along the bottom of a river; logs dragged along
the bottom of a river can leave deep flute casts.
Convolute bedding - ANSWERScomplex folding/crumpling of beds or lamination
flame structures - ANSWERSThese sedimentary structures form as denser droplets of sand sink
into underlying mud.
answers
Allogenic forcing - ANSWERSControls external to the depositional system. Examples: climate
change, tectonics, sea-level
Subsidence - ANSWERSPhysical sinking of Earth's crust
Isostasy - ANSWERSThe balancing of the downward force of the crust and the upward force of
the mantle.
Provenance - ANSWERSplace or source of origin of sediment
PHI SCALE - ANSWERSExpresses grain size on a logarithmic scale. Phi values increase
arithmetically as the grain size decreases geometrically.
fissility - ANSWERSThe property of splitting easily into thin layers along closely spaced, parallel
surfaces, such as bedding planes in shale.
Ortho / Para Conglomerate - ANSWERSClast vs Matrix Supported
BED SHEAR STRESS - ANSWERSDifferential force a grain feels from bottom to top
grain reynolds number - ANSWERSIncrease means increase in grain size, shear velocity &
turbulence, or a decrease in kinematic viscosity. Measures Turbulence of a fluid.
, Froude number - ANSWERSFr; dimensionless parameter that is used as a quantitative measure
of whether sub-critical or supercritical flow will occur
Saltation - ANSWERSThe movement of sand or other sediments by short jumps and bounces
that is caused by wind or water. Type of Bedload movement.
Laminae - ANSWERSBedding planes less than 1 cm in thickness
Imbrication - ANSWERSOverlapping of elongated clasts in upstream direction
Clinoform Components - ANSWERSTopset, Foreset (Middle), Bottomset
Tabular vs Trough crossbedding - ANSWERS2D dunes vs 3D dunes (curves)
flaser, wAVY, LENTICULAR - ANSWERSripple bedding with increasing mod content
ebb, slack, flood tide - ANSWERSoutward tide, non-moving, inward tide
groove cast - ANSWERSformed by dragging pebble, wood, shells, etc. in flow
flute casts - ANSWERSU-shaped imprints formed along the bottom of a river; logs dragged along
the bottom of a river can leave deep flute casts.
Convolute bedding - ANSWERScomplex folding/crumpling of beds or lamination
flame structures - ANSWERSThese sedimentary structures form as denser droplets of sand sink
into underlying mud.
