Abstract: The storm-dominated, high-energy, cool-water Lincoln Shelf occupies the central part of the southern Australian continental margin. Carbonate sediments on this modern distally-steepened ramp were produced by slow deposition during the Terminal Quaternary Sea-level Cycle (0 75 Ka), a high-amplitude, asymmetric cycle of sea-level change. The 50 to 150-mwd (meters water depth), 120-170 km-wide surface is a rocky substrate covered by a patchy, m-scale, palimpsest sediment veneer composed mostly of bryozoans, molluscs, foraminifers and coralline algae. Facies of the condensed Terminal Quaternary Sequence are interpreted to reflect accumulation during different parts of the Terminal Quaternary Sea-level Cycle that are now variably mixed. Accumulation during early stages of the Terminal Quaternary Regression, Isotope Stage-3/4 (IS-3/4), when sea level fluctuated between 30- and at least 60-mwd, took place in a series of shallow marine to paludal environments. Small-scale, 5th-order sea-level fluctuations resulted in recurring deposition, surf-zone reworking and exposure. Such conditions generating Relict Particles, brown- colored, abraded grains filled with carbonate precipitates, that are now concentrated on the middle to inner shelf (< 100-mwd). The Terminal Quaternary Lowstand (early IS-2) at 120-mwd resulted in deposition on the outermost shelf and exposure of the middle and inner shelf. This was a period of mesotrophic conditions and overall upwelling, leading to prolific bryozoan growth and the formation of a bryozoan biostrome at the shelf edge. These conditions continued during the early Terminal Quaternary Transgression (late IS-2) resulting in shelf facies rich in articulated coralline algal particles and rhodolites. Rapid sea-level rise, coupled with a change to more oligotrophic conditions during the late Terminal Quaternary Transgression (early IS-1), drowned these environments and resulted in belts of Stranded Particles on the middle to outer shelf. The modern setting, during the present Terminal Quaternary Highstand, reflects a complex oceanography. Waters are mildly oligotrophic, with yearly incursion of warm, oligotrophic waters from the west, seasonal upwelling of mesotrophic waters and annual outflow of cold, saline bottomwaters from the large shallow embayment of Spencer Gulf. Recent Particles are diverse: bivalves dominate inner-middle shelf sediments; bryozoans are most abundant on the outer shelf; shelf sediments opposite Spencer Gulf saline outflows are rich in benthic foraminifers; and corallines are most abundant inshore. The moribund biostrome is now populated by a rich and diverse suite of deeper water bryozoans and ahermatypic corals. Sediments on the western part of the shelf, with scattered large foraminifers, illustrate the sporadic influence of warmer waters.

Abstract The carbonate platforms of northeast Australia, the Great Barrier Reef province and the Eastern, Queensland, and Marion Plateaus, contain a record of the complex interactions between the factors that controlled carbonate deposition over the past 60 m.y. Analysis of the extensive geological and geophysical data shows that both long-term (plate motion and subsidence) and short-term (rifting, eustasy, climate, oceanography, and collision) factors influenced platform evolution. –The size, shape, and location of the high-standing structural features on which the carbonate platforms developed was determined by continental rifting. –Northward plate movement controlled the distribution of climate-related facies within the Great Barrier Reef sequence, resulting in a tropical carbonate wedge that thins and becomes younger to the south and overlies temperate and subtropical facies. –Large-scale facies distribution patterns reflect the complexities of the subsidence regimes that affected the northeast Australian platforms. The simple subsidence situation, where high-subsidence rates favoring backstepping are succeeded by lower subsidence rates favoring progradation, was complicated by episodes of accelerated subsidence. –Sea-level variation directly controlled platform facies: rising and high sea-level periods favored increased carbonate deposition, whereas falling and low sea-levels restricted carbonate deposition, caused increased terrigenous input along the shelf, and in many cases resulted in exposure of the platforms and the formation of unconformities. –In addition to the overall climatic consequence of northward plate motion, facies sequences show the effects of the development throughout the Cenozoic of more pronounced latitudinal climatic zonation and progressive high-latitude cooling. –Chemical and physical oceanographic factors affected platform evolution in various ways, e.g., the inhibition of reef development by high oceanic-phosphate levels during the Early and Middle Miocene, and deposition of facies reflecting the progressive development of the east Australian current from the Miocene. –The development of a foreland basin on the northern edge of the northeast Australian region initially caused a dramatic expansion of carbonate facies, but ultimately terminated carbonate deposition as a result of uplift and inundation by clastic detritus. General conclusions applicable to other carbonate platforms may be deduced from analysis of the factors that controlled deposition on the northeast Australian platforms. The evolution of any particular carbonate platform will be fundamentally dependent on whether the subsidence history is simple or complex; whether plate motion is toward or away from the tropics; and whether movement from one climatic regime to another is slow or rapid. Short-term eustatic, climatic, and oceanographic factors are responsible for complexities in the facies sequences produced. The most complex and varied carbonate platform sequences will be those deposited under the influence of compound subsidence, together with plate motion through a range of climatic zones over a substantial time period. The northeast Australian carbonate platforms illustrate such a complex history and demonstrate that facies diachroneity is a fundamental characteristic of complex carbonate platform development.