Delta Flashcards
- the point where it reaches a standing body of water, which may be a lake or the sea.
River Mouth
- a river mouth where there is a mixture of fresh water and seawater with accumulation of sediment within its confines, but without any build-out into the sea.
Estuary
sites in the stratigraphic record for the formation and accumulation of fossil fuels.
Delta
- a discrete shoreline protuberance formed at a point where a river enters the ocean or other body of water.
- forms where sediment brought down by the river builds out as a body into the lake or sea.
Delta
formed by deposition of silt at the mouth of a stream or by overflow along the lower stream courses.
Delta Top
or
Delta Plain
- the sloping portion of a delta, developed offshore from the bar at the mouth of a river.
Delta Front
- the area furthest away from the delta front wherein sediments will deposit.
Prodelta
- an elevated region of sediment typically found at a river delta which is located at the mouth of a river where the river flows out to the ocean.
Mouth bar
- a stream that branches off and flows away from a main stream channel.
Distributary Channel
- sheltered areas along the edge of the delta top where the channels build out elongate lobes of sediment.
Interdistributary Bays
- a steep inclined area away from the delta top.
- the slope varies from only 1° or 2° in many fine-grained deltas to as much as 30° in some coarse-grained deltas.
Delta Slope
- the site of deposition of bedload material.
Subaqueous Mouth Bar
- the growth of a river delta farther out into the sea over time.
Progradation
- the increase in land elevation, typically in a river system, due to the deposition of sediment.
Aggradation
occurs in microtidal settings with limited wave energy, where delta-lobe progradation is significant and redistribution of mouth bars is limited.
Give an example
River-Dominated Delta
Mississippi Delta
a type of delta characterized by mouth bars reworked into shore parallel sand bodies and beaches.
Give an example
Wave-Dominated Delta
- Rhone Delta
- Paraiba Delta
- a type of delta which exhibit tidal mudflats and mouth bars that are reworked into elongate sand bodies perpendicular to the shoreline.
Give an example
Tide-Dominated Delta
- Ganges Delta
- Copper Delta
- a particular delta formed by the combination of a supply of coarse sediment and a steep basin margin.
Gilbert Type Delta
an essentially horizontal sedimentary layer deposited on top of a delta during floodstage.
Topset
- an inclined bed deposited along the front of a delta.
Foreset
- a layer of fine sediment deposited beyond the advancing edge of a delta and then buried by continuous delta growth.
Bottomset
