Abstract: Barrier
/Inlet System on the Florida Gulf Coast: A Holocene
Mixture of Carbonate and Siliciclastic Sediments that is a Model
for Good Reservoirs
DAVIS, RICHARD A., JR., Coastal Research Laboratory, Department of Geology, University of South Florida
The complex barrier
/inlet system on the Gulf Coast of the
Florida peninsula includes 30
barrier
islands and a like number of
tidal inlets. The diverse morphology of these elements gives rise
to the most complicated
barrier
system in the world. Mean annual
wave height is about 25cm and mean tidal range is less than one
meter. Hurricanes are important but infrequent occurrences on this
coast.
The siliciclastic, terrigenous component of this coastal complex
is well-sorted, fine quartz sand with a mean grain size of about
2.6phi. The carbonate component is dominantly molluscan skeletal
material although a few limestone rock fragments may also be
present locally. Most of this molluscan skeletal material is from
bivalves and is aragonitic in composition. The carbonate skeletal
component of the barriers ranges in abundance from less than 10
percent to more than 80 percent locally. Although the gravel
fraction of these sediments is essentially all skeletal, the sand
fraction also contains abundant carbonate. This sand sized
carbonate ranges from being essentially absent to more than 80
percent along the barrier
coast.
Shell gravel is concentrated in the foreshore beach and in tidal-channel fill sequences. Carbonate sand is most abundant in the nearshore area. Such accumulations when preserved in the stratigraphic record could make excellent reservoirs upon dissolution of the carbonate fraction; both shell gravel and sand.
AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah