hyperpycnal), the delta can be lobate, fan-shaped, elongate, or digitate. The delta progrades into the estuary by
subaqueous deposition of a fan of sand or bar-finger
sand, shoaling to high-tidal levels and river flood levels.
The fans of sand or bar-finger sands are capped by tidal
deposits, levee deposits, and floodplain deposits,
while interdistributary bays are filled with tidal flat
deposits shoaling to floodplain deposits. The overall
delta form consists of (1) a subaerial part whose
plan shape is lobate, fan-shaped, elongate, or digitate
and whose geomorphic/sedimentologic components
include levee banks, floodplains, high-tidal to supratidal
flats, lagoons, and abandoned channels; (2) a delta
slope comprised of sheets, fans or bar-fingers of
sand or muddy sand, and laterally intervening bays
underlain by sand or mud; and (3) a prodelta usually
underlain by mud that forms a peripheral apron around
the delta slope.
Deltas, Figure 5 The traditional tripartite classification of deltas of Figure 4 with some intra-estuarine deltas from southwestern
Australia on the ternary diagram.
DELTAS
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