Page 122 - Carbonate Sedimentology and Sequence Stratigraphy
P. 122

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.
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