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Sedimentology - Coggle Diagram

- - - - Longshore currents and wave action is more important than tidal currents.
        
        They are fragile, constantly changing ecosystems. Some can extend for 100 miles or more off the coast. Separated from the mainland by a shallow sound, bay, or lagoon.
  - - - Eustatic sea level: global sea level. Involves: tectono-eustasy (changes in ocean basin volume), glacio-eustasy (changes in sea water volume driven by glacial water), aquifer-eustasy (changes in sea water volume driven by aquifer water).
      - Regression leads to onlap sequencing: this is the termination of shallowiy dipping, younger strata against more steeply dipping older strata
        
        Each sequence consists of multiple packages of strata, called systems tracks.
        Lowstand, transgressive, and highstand. Every systems tract contains parasequences.
        
        Parasequences=minor fluctuations in sea level. They are shallowing upward cycles bound by flooding surfaces.
    - - Eustasy is worldwide change in sea level as contrasted with local uplift or subsidence(isostasy) of the land; equilibrium between the earth's crust and the mantle.
      - Three options for transgressive-regressive cycles: 1) Global sea level rises and falls (eustasy). 2) Crust rises and falls (isostasy). 3) Tectonic movements and global sea level change simultaneously.
    - - The factors of transgression and regression: 1) Global (Eustatic) Sea-level change, Earth's surface remains fixed and global sea level changes. 2) Regional/Local subsidence/uplift, Earth's surface changes and global sea level remains fixed.
    - - Retrogradation is characterized by deepening upward sequence. Beds are deposited successively landward.
      - Progradation=shallowing upward
- - - - Braided rivers form when the bed load has more sediment than the suspended load.
      - Braided rivers are found near mountainous areas; steep gradient.
      - Broad and shallow w/ a steep gradient. "a mile wide and a foot deep".
        
        At the upper reaches of fluvial systems.
        
        Braided rivers have rapid discharge fluctuations.
      - Channel bars (longitudinal, transverse) are main sites of sediment accumulation.
    - - Oxbow lakes are NOT found near braided rivers. They are found near meandering rivers.
        
        Meandering rivers will move/migrate towards the eroding bank and therefore will have a more uniform shape than braided rivers.
        
        Meandering Rivers are located on flat terrain that reduces the flow speed of water, allowing the river to curve or "meander". They have a more uniform shape than braided rivers.