The south Australian Eucla Shelf belongs to the world's largest cool-water carbonate sedimentary system. During the Pleistocene, it exported large amounts of sediment to the shelf edge and upper slope resulting in an expanded sedimentary wedge. Wedge-internal clinoforming seismic reflectors suggest a stacking of the deposits into genetic sequences. High-resolution stable oxygen and carbon isotope, point counting, grain size, and carbonate mineralogical XRD analyses were carried out to characterize these genetic sequences along a dip-parallel transect of three ODP Leg 182 drill holes located between the shelf edge and upper slope. Oxygen and carbon isotope fluctuations show that the genetic sequences formed as a response to sea level fluctuations. Within the genetic sequences, facies differentiation and sediment volume partitioning occur along the transect. Lowstand deposits are fine grained and contain more sponge spicules and micrite. Highstand deposits are coarse grained with tunicate spicules, brown bioclasts, as well as bryozoan and corallinacean debris. Boundaries separating highstand and lowstand deposits are triggered by sea level fall, and are expressed as abrupt grain size changes or as turning points in grain-size trends. Analyzed components vary in abundance along the transect. Genetic sequences show dip-parallel variations in thickness combined with changing relative proportions of lowstand versus highstand deposits.

Depositional geometries as imaged in seismic lines, logging data, and quantitative petrographic data were used to analyse the slope and toe of slope deposits of the Miocene distally steepened carbonate ramp of Great Bahama Bank. The shedding pattern along the slope of this ramp is more complex than it is along the slope of the Pliocene±Pleistocene flattopped carbonate platform. Compositional changes and compositional trends of periplatform sediments correlate with the positions of geophysically-defined sequence boundaries. Two types of depositional sequences occur. The first sequence is characterised by laterally traceable sequence-internal reflections, whereas the second type contains major intrasequential incisions. Erosional incisions and sedimentary infills of these canyons by turbidites formed during sea-level lowstands, as is indicated by the composition of the turbidites having a mixture of shallow-water and pelagic particles. Highstand turbidites are characterised by more extensive, laterally traceable geometries and by the occurrence of abundant shallow-water particles. In contrast to highstand turbidites shed from the Pliocene±Pleistocene flat-topped platform, shallow-water components in highstand turbidites of the Miocene ramp are of skeletal origin. The stacking pattern of the periplatform deposits is controlled by sealevel fluctuations. Four orders of sea-level changes are distinguished. Third-order cycles are delimited by sequence boundaries, and fourth (100,000 a) order cycles govern the bundling of turbidites into packages. Fifth (40,000 a) and sixth (23,000 a) order cycles are recorded in the background sediments and resolvable with spectral analysis.

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