Deltaic Depositional Systems

Presentation Transcript

Deltaic Depositional Systems Modern and Ancient Arno River Delta (Med) (a wave commanded and designed delta)

Deltaic Depositional Systems Locus of voluminous terrigenous clastic residue amassing where fluvial dispersal frameworks experience standing water Most regular in dying down bowl settings (uninvolved mainland edges) where real waterway frameworks transport vast volumes of silt. Advanced Gulf of Mexico And the Mississippi River Delta (a waterway ruled delta)

Importance Of Deltas Site of generous fossil fuel asset amassing Coal, Oil, and Natural Gas

Importance Of Deltas Diverse and productive biological communities Common site of huge human populace focuses Nile River Delta (Med Sea) (a designed, wave/stream commanded delta) Tigris & Euphrates River Delta (Persian Gulf)

Main Geological Characteristics Of Deltas Isopach thick... major stratigraphic segment of (Terrigenous Clastic) sedimentary bowl fill Mississippi Delta

Main Geological Characteristics Of Deltas Regressive - Progradational progressions Abandonment – Transgressive Stage

Main Geological Characteristics Of Deltas Contemporaneous non-marine - minor marine - to basinal depositional frameworks Numerous sub-situations (each of a scale like that of most other depo frameworks)

Delta Types Constructional Deltas Dominated by the fluvial framework emphatically progradational/backward Lobate – Elongate Destructional Deltas Dominated by marine procedures regular marine modifying with transgressive interims Cuspate (transitional to interdeltaic frameworks)

Main Processes Influencing Delta Depositional Systems Climate Relief Fluvial Discharge (water volume and time variety) Sediment load and sort River mouth forms Tidal Processes Wave vitality

Main Delta Sedimentary Facies Generic River-Dominated Delta Model expansive waterways wide retire low wave vitality low tidal range

Generic River-Dominated Delta Model Upper Delta Plain above most elevated high tide low slope/winding stream frameworks crisp water lakes & swamps Main Delta Sedimentary Facies

Generic River-Dominated Delta Model Lower delta plain between the tides Distributary channels Inter-distributary straight fill levees Main Delta Sedimentary Facies

Generic River-Dominated Delta Model Subaqueous (Delta Front) beneath least low tide distributary mouth bar - bar finger sands inlets Main Delta Sedimentary Facies

Delta Front Progradation

Generic River-Dominated Delta Model Prodelta Offshore transitional to open marine Normal Marine Shelf High natural profitability Abundant droops and syndepositional twisting Main Delta Sedimentary Facies

High wave vitality, open coasts, solid longshore ebbs and flows Non-marine, marsh to Eolian rise Arcuate to strand-parallel sand overwhelmed facies, hindrance island successions Generic Wave Dominated Delta Model Rhone River Delta (Med) (a wave ruled delta)

High Tidal Range Extensive lower delta plain/tidal mudflats Shore opposite, extend sand commanded facies, tidal channel stores Generic Tide Dominated Delta Model Ganges - Brahmaputra River Delta (Indian Ocean) (a tide ruled delta)

Transgressive Mississippi Delta Model

Transgressive Mississippi Delta Model

Transgressive Mississippi Delta Model

Environmental Issues in Modern Deltas Damming, Dredging, Diverting Coastal Land misfortune (disintegration/subsidence) Coastal Pollution Nutrient stacking, anoxic occasions Petroleum sullying Habitat Destruction arrive misfortune, tainting, and advancement

Environmental Issues in Modern Deltas Mississippi Delta Coastal Land misfortune Louisiana's waterfront wetlands, a national asset supporting 30% of the country's fisheries and the greater part of the wintering ducks in the Mississippi Flyway, are at hazard from the yearly transformation of an expected 35-45 mi 2 of wetlands to vast water. Louisiana's wetland misfortune rate is the most noteworthy of any state in the country. The procedures bringing on wetland misfortune in seaside Louisiana are intricate and shifted. Immense vitality foundation Louisiana streets, pipelines, and transmission and circulation frameworks transport more than 30 percent of the country's oil and regular gas supplies through the state

Coastal Elevation in Louisiana

Nature's Revenge Louisiana's vanishing wetlands