SEDIMENTARY ARCHIVES Marine Environment SEDIMENTARY ARCHIVES Marine Environment Continental Shelf...

SEDIMENTARY ARCHIVES

Marine Environment


Marine Environment

Continental Shelf

Flat, smooth regions that fringe continents

Few km to 300 km wideLow tide to 200 m depth

Similar to continental deposits

Shelf planed off by changes in sea level


Marine Environment

Continental Shelf

Most eroded continentalmaterial ends uphere

Primarily sand, silt, clay

Carbonates develop whereclastic influx is low

In shallow marine biologicimpact is great


Marine Environment

SEDIMENTARY ARCHIVESMarine Environment

Continental SlopeSteeper slope than shelf300 to 3200 m deepZone of erosion as material

from shelf moves to abyssal plain

Turbidity currents(Waterville Fm.)

Mostly fine sand, silt, clay

SEDIMENTARY ARCHIVESMarine EnvironmentContinental Slope

Turbidity Currents


Continental Rise More gradual slope at baseof continental slope


Deep Marine – Abyssal PlainDepths >3200 mOnly fine clay, volcanic ash and

calcareous and siliceousoozes accumulate

Carbonate compensation depth Oozes are skeletal

remains

Coarse-grainsSlumpsIce-rafted debris


Transitional EnvironmentsRepresents the margin between the oceans and contintents

(Shorelines and coasts)

Clastic sediments


Transitional Environment

Carbonate sediments



DeltasΔ



DeltasPrograding DeltaDeposition > Erosion

Upward progression of fines to coarse

Subsiding basin

Contain organic matterPetroleum producing

Mississippi River Delta



Deltas



DeltasDeposition = Erosion

Concentric enlargementof delta

Niger River Delta



DeltasErosion > Deposition

No visible delta

Kennebec River



Barrier Islands



Barrier Islands

Usually sandy

Organisms include bivalves, gastropods, echinoids, and crustaceans



Lagoon

Shallow areas land- ward of barrier islands

Can be protected inlets

Sediments usually silty



Lagoon



Tidal Flats



Tidal Flats

Exposed and covered by tides

Harsh environmentAlternating wet and dryGenerally fine-grainedDiversity is lowIncludes bivalves, gastropods,

crustaceans, worms,and cyanobacteria

SEDIMENTARY ARCHIVES Marine Environment SEDIMENTARY ARCHIVES Marine Environment Continental Shelf...

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