sedimentary archives marine environment sedimentary archives marine environment continental shelf...
Post on 22-Dec-2015
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SEDIMENTARY ARCHIVES
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
SEDIMENTARY ARCHIVES
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
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 Environment
Continental Rise More gradual slope at baseof continental slope
SEDIMENTARY ARCHIVESMarine Environment
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
SEDIMENTARY ARCHIVES
Transitional EnvironmentsRepresents the margin between the oceans and contintents
(Shorelines and coasts)
Clastic sediments
SEDIMENTARY ARCHIVES
Transitional Environment
DeltasPrograding DeltaDeposition > Erosion
Upward progression of fines to coarse
Subsiding basin
Contain organic matterPetroleum producing
Mississippi River Delta
SEDIMENTARY ARCHIVES
Transitional Environment
DeltasDeposition = Erosion
Concentric enlargementof delta
Niger River Delta
SEDIMENTARY ARCHIVES
Transitional Environment
DeltasErosion > Deposition
No visible delta
Kennebec River
SEDIMENTARY ARCHIVES
Transitional Environment
Barrier Islands
Usually sandy
Organisms include bivalves, gastropods, echinoids, and crustaceans
SEDIMENTARY ARCHIVES
Transitional Environment
Lagoon
Shallow areas land- ward of barrier islands
Can be protected inlets
Sediments usually silty