Geology Reference
In-Depth Information
Fig. 9.12
Photos showing different morphologic and sedi-
mentary features at the transitional zone between the salt
marsh and the bare flats: (
a
) a gradual transition profile with
soft muddy deposits on the flats, denoting accretion; (
b
) the
erosion cliff of several centimeters high at the front of the salt
marsh; (
c
) small erosion ponds on the salt-marsh land; (
d
) erosion
remnant patches of partly consolidated salt-marsh deposits;
(
e
) abundance of mud pebbles and shell debris on the erosion
remnant patches; (
f
) swash sand sheet over the salt-marsh
land
barred tidal flats (Frey et al.
1989
; Wells et al.
1990
;
Alexander et al.
1991
; Fan et al.
2004a
; Yang et al.
2005
). This is typically true for non-estuarine open-
coast tidal flats, where the flats are exposed directly to
the open sea. In the open-mouth estuaries, the main
channels usually run parallel or oblique to local shoreline,
but their landward branches are highly potential to cut
deeply into the tidal flats, typically for those in the
inner, less-exposed part of the estuaries. Although tidal
channels are less developed on the bare flats, the broad
vegetated flats tend to have tidal-creek networks as
intricate as those on the sheltered tidal flats (Ren
1985
;
