Geology Reference
In-Depth Information
Fig. 19.3
Field photos of representative subtidal and associated
environments, Bahamian Archipelago. (
a
) Shallow subtidal
region, nearshore Crooked Island. The patchy pattern in the
foreground is formed by burrow mounds and adjacent depres-
sions. (
b
) Underwater photograph of shallow subtidal, nearshore
marine environment, nearshore from the same area as illustrated
in part A. Note seagrass and calcareous green algae (
arrows
),
and the irregular topography caused by burrowing. (
c
) Shallow
subtidal to lower intertidal area in a pond, Andros Island. Note
sparse mangroves and the burrows in the foreground. (
d
) Large
tidal channel and upper intertidal levee, Three Creeks, Andros
Island. (
e
) Large tidal channel bordered by mangrove swamp,
Caicos. (
f
) Termination of small tidal creek into pond, and
“delta” like form (outlined by
dashes
), Andros Island
Fig. 19.4
Field photos of representative intertidal environments
and sediments, Bahamian Archipelago. (
a
) Mangrove pond,
with widespread dwarf red mangroves, Andros Island. (
b
) Sediments
from mangrove pond, including abundant high-spired gastro-
pods and Batophora, a non-calcifying green alga, Andros Island.
Pencil for scale. (
c
) Short push core, illustrating light
grey
(oxidizing) color and thin laminations in lower intertidal zone,
Andros Island. This sample illustrates the dark reduced band
below the brownish algal mat at the surface. (
d
) Scytonema
pincushions from the microbial marsh (“low algal marsh” of
Hardie
1977
), Andros Island. Bootie for scale. (
e
) Mudcracked,
leathery microbial mat penetrated by black mangrove pneu-
matophores from the upper part of the microbial marsh (“high
algal marsh” of Hardie
1977
), Andros Island. Pencil for scale.
(
f
) Lithifi ed crusts associated with microbial mats, lower part of
high algal marsh, Andros Island. Pencil (
circled
) for scale
