Sedimentary Cycle Processes Flashcards
is a simple model of the processes
responsible for the production of sediments and
sedimentary rocks.
Sedimentary Cycle
Called second set of processes
Erosion
referred when sediments accumulate on Earth’s surface
Deposition
sedimentary material is moved or transported in solid or dissolved form across Earth’s surface.
Transportation
Erosion rates depend primarily on: (4)
relief
vegetative cover
precipitation
the type of erosion agents involved
Erosion, transportation and deposition agents
4
Water
Wind
Glaciers
Mass flows
is the major agent by which sediments are eroded, transported and deposited on Earth’s surface.
Water
is the major agent by which
sediments are eroded, transported and
deposited on Earth ’ s surface.
Fluid Flow
possess shear strength. The major stress that initiates flow is the tangential force of gravity (gt), which increases with increasing slope angle.
Plastic Flow
adjacent parcels of the flow move roughly parallel to one another in a well -organized pattern, with negligible mixing between them.
Laminar Flow
adjacent parcels of the flow move in chaotic patterns and random mixing between parcels is common
Turbulent Flow
Can be used to predict whether flow will be
laminar or turbulent
Essentially a ratio between the inertial forces and
the viscous forces in a fluid medium
named after
Reynold’s Number
Osborne Reynold
are capable of picking up loose clay, silt and sandsized debris from the land surface
Wind
In temperate (warm based) glaciers, erosion of the bedrock by ice occurs by two processes
Abrasion and Plucking.
is most common where a glacier flows over an obstacle. The blocks plucked by the ice and subsequently incorporated into the glacier are often
loosened by subglacial freeze–thaw action.
Glacial Plucking
is most effective where the land surface is
not bound by plants and hence it is prevalent where
vegetation is sparse, in cold regions, such as near the
poles and in high mountains, and dry deserts.
Wind Erosion
- occurs by the frictional action of blocks of material embedded in the ice (‘tools’) on the bedrock. The scouring process creates rock flour, clay and
silt-sized debris that is incorporated into the ice.
Glacial Abrasion
On steep slopes in mountainous areas and along
cliffs movements downslope under gravity are
commonly the first stages in the erosion and
transport of weathered material.
Mass Flow
It can attain much higher velocities and is generally
characterized by turbulent flow
Wind
TRANSPORT MEDIA (4)
GRAVITY
WATER
AIR
ICE
Simplest mechanism of sediment transport where
sediments move under the influence of gravity
down a slope
Gravity
movements of material under gravity and
accumulates as a chaotic mass of material at the base of the slope.
Rock Fall
coherent mass of bedrock that has moved
downslope without significantly breaking up in the
process.
Landslide
slow movement of lubricated regolith/soil.
Soil Creep