Page 122 - Carbonate Sedimentology and Sequence Stratigraphy
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CHAPTER 7: SEQUENCE STRATIGRAPHY OF THE T FACTORY 113
A) B)
c
c
c
C)
r
c
Fig. 7.9.— Bahamian oolite shoals in transgressive and highstand condition. A) Cat Cay - transgressive shoal. Sand bars are thin and
anchored behind Pleistocene islands; tidal channels (c) are wide. B) Joulters Cay highstand shoal. Tidal channels are few and narrow,
sand bars have coalesced to one continuous belt. C) Prograding beach ridges (r) and eolian dunes on Joulters shoal.
B) depth to
bedrock
0
1 1
2 2
3 3
4 4
5 6 5
0 10
km
Fig. 7.10.— Tidal flats west of Andros Island, Bahamas. A)
Satellite image showing NW tidal flats in transgressive conditions
(T), SW flats in highstand condition (H). On transgressive flats,
seaward beaches are ragged and erosional, channels deep and
well connected. Channel network efficiently floods and drains the
standing water of the inner flats. On the highstand flats, seaward
beaches are smooth and accreting (older beach ridges indicated
by x). Open channels are scarce, most have been choked by pro-
grading beach ridges. After Harris and Kowalik (1994), reprinted
by permission of the AAPG whose permission is required for fur-
ther use. B) Ancient shore line positions and thickness of the
highstand wedge of the SW-facing flats. After Hardie and Shinn
(1986), modified.