Karst sub-basins and their relationship to the transport of Tertiary siliciclastic sediments on the Florida Platform - Perspectives in Carbonate Geology - page 185

F

Seismic trackline
coverage Evans (1989)
Fig. 9 cross-sections

F'

E'

F"

E"

G'

G"

W

Fig. 8. Depth to basement map of Charlotte Harbor
revealing the multiple smaller sub-basins lying beneath
this modern estuary. Maximum relief of sub-basins (to
Arcadia Formation) is ~100 m.

Fig. 7. Seismic data, track-line location in Charlotte Harbor
and the Caloosahatchee River. Note location of cross-
sections shown in Fig. 9.

systems that migrated approximately 200 km south
to the Florida Keys (Cunningham et al ., 2003).

lowstands as well (Popenoe et al ., 1984; Scott,
1990). During lowstands of sea level, these sub-
basins caused the local-to-regional streams and
rivers to fl ow into them forming lakes or swamps
(Edgar et al ., 2002). During high stands of sea
level, these sub-basins became estuaries, or open-
marine systems, but were fi lled primarily by
prograding deltas.
It is unclear why the sub-basins are restricted
and located where they are. Their location may
be related to selective faulting and fracturing
of the Mesozoic and Cenozoic carbonate
succession overlying the Palaeozoic-PreCambrian
basement - perhaps related to reactivation of
regional transform faults (Klitgord et al ., 1984;
Sheridan et al ., 1988). Fracturing and faulting
may have been stimulated by the early Cenozoic
collision with the Cuban arc system (Bralower &
Iturralde-Vinent, 1997; Moretti et al ., 2003;
Pindell et al ., 2006). Or, fracturing may have
occurred throughout geological time resulting

DISCUSSION

Formation and fi lling of the Tampa Bay and
Charlotte Harbor sub-basins

Since the deformed, underlying limestone is late
Oligocene to middle Miocene in age and the over-
lying siliciclastic sediments are late Miocene to
early Pliocene, the sub-basins probably formed
during the middle to late Miocene. The style of
deformation indicates that deep-seated dissolu-
tion caused overlying stratigraphic collapse pro-
ducing a complex of sags, warps and folds, which
combined to form the Tampa Bay and Charlotte
Harbor sub-basins. This dissolution and collapse
most probably occurred during the extended
late Miocene sea-level lowstand shown in Fig. 13
(TB3.1 to TB3.3) although dissolution was
probably widespread throughout all Cenozoic