Geology Reference
In-Depth Information
tombolo tails eventually reached the mainland (Fig.
19.21c, d
). Longshore transport and lateral island
accretion focused tidal fl ow in the inlets and led to
development of oolitic deltas, as well as isolation of
lagoons, leading to lower-energy conditions and
muddy deposits. Within the lagoons, subenvironments
along the coast are prograding and infi lling the lagoons
(Fig.
19.21c
; cf. Fig.
19.17
) at rates averaging 0.75 m/
year (Lokier and Steuber
2008
) .
Ball MM, Shinn EA, Stockman KW (1967) The geologic effects
of Hurricane Donna in South Florida. J Geol 75:583-597
Berkeley A, Rankey EC (in review) Carbonate tidal fl ats of
Crooked Island, southern Bahamas Sedimentology.
Black M (1933) The algal sediments of Andros Island, Bahamas.
R Soc Lond Philos Trans Ser B 222:165-192
Boudreau BP (1994) Is burial velocity a master parameter for
bioturbation? Geochem Cosmoch Acta 58:1243-1249
Butler GP (1970) Holocene gypsum and anhydrite of the Abu
Dhabi, Trucial Coast, Persian Gulf: An alternative explana-
tion of origin. Proc 3rd Int Salt Symp, Northern Ohio Geol
Soc, Cleveland, pp 120-152
Cloyd KC, Demicco RV, Spencer RJ (1990) Tidal channel levee
and crevasse-splay deposits from a Cambrian tidal channel
system: a new mechanism to produce shallowing upward
sequences. J Sediment Petrol 60:73-83
De Groot K (1973) Geochemistry of tidal fl at brines at Umm
Said, SE Qatar, Persian Gulf. In: Purser BH (ed) The Persian
Gulf. Springer, Berlin/New York, pp 377-394
Enos P (1989) Islands in the bay - a key habitat of Florida Bay.
Bull Mar Sci 44:365-386
Enos P, Perkins RD (1979) Evolution of Florida Bay from island
stratigraphy. Bull Geol Soc Am 90:59-83
Evans G, Schmidt V, Bush P, Nelson H (1969) Stratigraphy and
geologic history of the sabkha, Abu Dhabi, Persian Gulf.
Sedimentology 12:145-159
Gebelein CD (1974) Guidebook for Modern Bahamian Platform
Environments. Geological Society of America annual meeting
fi eld trip guide, 93 p
Gebelein CD (1975) Holocene sedimentation and stratigraphy
southwest Andros Island, Bahamas. 9th International sedi-
mentological congress, Nice, Theme 5, 1, pp 193-198
Gebelein CD (1977) Dynamics of recent carbonate sedimenta-
tion and ecology. Cape Sable Florida. In: EJ Brill, Leiden
120 p
Ginsburg RN, Hardie LA (1975) Tidal and storm deposits north-
western Andros Island Bahamas. In: Ginsburg RN (ed) Tidal
deposits: a casebook of recent examples and fossil counter-
parts. Springer, Heidelberg
Ginsburg RN, Hardie LA, Bricker OP, Garrett P, Wanless H (1977)
Exposure index: a quantitative approach to defi ning position
within the tidal zone. In: Hardie LA (ed) Sedimentation on the
modern carbonate tidal fl ats of northwest Andros Island, baha-
mas, The John Hopkins University Press, Baltimore, pp 7-12
Grotzinger JP (1986) Cyclicity and palaeoenvironmental dynamics
Rocknest platform northwest Canada. Bull Geol Soc Am
97:1208-1231
Hardie LA (1977) Sedimentation on the modern carbonate tidal
fl ats of northwest Andros Island Bahamas, The Johns
Hopkins University studies in geology no. 22. The Johns
Hopkins University Press, Baltimore, 202 p
Hardie LA (1986) Stratigraphic models for carbonate tidal-fl at
deposition. Colo Sch Min Quart 81:59-74
Hardie LP, Garrett P (1977) General environmental setting. In:
Hardie LA (ed) Sedimentation on the modern carbonate tidal
fl ats of northwest Andros Island Bahamas, The Johns
Hopkins University studies in geology. The Johns Hopkins
University Press, Baltimore, pp 12-49
Hardie LA, Ginsburg RN (1977) Layering: the origin and envi-
ronmental signifi cance of lamination and thin bedding. In:
Hardie LA (ed) Sedimentation on the modern carbonate tidal
fl ats of northwest Andros Island Bahamas, The Johns
19.6
Summary
The Holocene carbonate tidal fl ats of the Bahamas and
Turks and Caicos have provided important conceptual
models that have been widely applied to understand
ancient successions. The most expansive of these tidal
fl ats occur on leeward or protected fl anks of bedrock
islands, in low-energy settings in which muddy sedi-
ments accumulate as a result of sediment transport
onto the intertidal and supratidal areas. Tidal fl ats com-
monly have only subtle relief, but due to the stressful
environment, even cm-scale changes in topography
lead to marked shifts in fl ora, fauna, and sedimentary
structures. These changes result in accumulations that
are very strongly zoned with the topography, although
the spatial patterns of different subenvironments is
quite variable within and among systems. Carbonate
tidal fl ats in the Bahamian Archipelago can include a
range of geomorphic forms, and include channel net-
works, broad supratidal plains, and offl apping or ero-
sional shorelines. The stratigraphy of several tidal fl ats
record basal transgressive deposits, overlain by a gen-
erally shallowing-upward succession.
The arid tidal fl ats and sabkha of the Arabian Gulf
illustrate several contrasts to the more humid systems of
the Bahamas and Caicos. There, signifi cant quantities of
eolian sand can be supplied to the shoreline, where they
can be re-worked by longshore currents to form chenier
complexes. Likewise, due to the more arid setting, fewer
organisms (such as mangroves) thrive, and evaporites
are common. These systems are commonly interpreted
to form broadly offl apping successions.
References
Alsharhan AS, Kendall CGStC (2003) Holocene coastal carbonates
and evaporites of the southern Arabian Gulf and their ancient
analogue. Earth Sci Rev 61:191-243
