Contrasts between wave- and tide-dominated oolitic systems: Holocene of Crooked–Acklins Platform, southern Bahamas

摘要: As the stratigraphic record is neither homogenous nor isotropic, a fundamental challenge in sedimentary geology characterizing and predicting nature of variability. Although many nearshore to shallow-marine siliciclastic depositional systems have been grouped into wave-dominated tide-dominated classes, facies models carbonate not recognized or applied this distinction. To fill gap, purpose study compare contrast hydrodynamic processes, sedimentology, geomorphology, stratigraphy an oolitic shoal complex shoreline system from same area (Crooked–Acklins Platform, southern Bahamas). Field, petrographic, granulometric, remote-sensing, data illustrate marked contrasts between two end members. The shoreface near French Wells on leeward margin influenced by small (Hs <30 cm) waves only weak, wave-driven currents (<15 cm/s, net southward flow); passage Hurricane Irene (in 2011) had local impact shoreface. low-energy setting favors generation alongshore transport ooids peloids fine- medium-sized sand, has facilitated nearly 1 km progradation, forming geomorphic bodies with margin-parallel geometry. includes coarsening- shoaling-upward succession. In contrast, ~7-km-wide, southwestern dominated vigorous tidal excess 50 cm/s, reversing twice daily). These generate margin-normal bars channels consisting oolitically coated grains medium coarse sand size. Stratigraphically, above basal clast-rich deposit, sediment size sorting vary across shoal. open-ocean platformward flanks shoal, most impacted tide wave energy, include cleanest fines accumulating stabilized interior. Overall, aggraded expanded over bioturbated peloid–ooid sand. results reveal how sediment, differ tide- members, patterns broadly analogous several ancient examples. collectively processes that create multi-scale linkages among patterns, geological bodies, granulometry (e.g., porosity permeability). provide information could be used predict sedimentological geomorphical trends analogues.