Fraser Island (K'gari) and initiation of the Great Barrier Reef linked by Middle Pleistocene sea-level change

Abstract

The eastern Australia coastline is characterized by impressive coastal landforms and an extensive northward-moving longshore drift system that have been influenced by a stable, long-term tectonic history over the Quaternary period. However, the timing and drivers of the formation of two conspicuous landscape features—Fraser Island (K’gari) and the Great Barrier Reef—remain poorly understood. Here we use optically stimulated luminescence and palaeomagnetic dating to constrain the formation of the extensive dunes that make up Fraser Island, the world’s largest sand island, and adjacent Cooloola Sand Mass in southeastern Queensland. We find that both formed between 1.2 Ma and 0.7 Ma, during a global climate reconfiguration across the Middle Pleistocene transition. They formed as a direct result of increased amplitude of sea-level fluctuations associated with increasing global ice volume that redistributed previously stored sediment across the continental shelf. The development of Fraser Island dramatically reduced sediment supply to the continental shelf north of the island. This facilitated widespread coral reef formation in the southern and central Great Barrier Reef and was a necessary precondition for its development. This major reorganization of the coastal sedimentary system is probably not unique to eastern Australia and should be investigated in other passive-margin coastlines.

Reconstructing Holocene fire records using dune footslope deposits at the Cooloola Sand Mass, Australia

“…These dune fields have existed since ca. 800 ka (Ellerton et al, 2020(Ellerton et al, , 2023. They are composed of large parabolic dunes that contain the world's largest rainforest and unconfined aquifer on a sand island and are home to rare flora and fauna (UNESCO, 2021).…”

“…The timing of dune stabilization is penecontemporaneous with the initiation of dune sediment erosion and deposition (i.e., the transition from eolian to colluvial processes) (Patton et al, 2022b). These processes have been occurring for at least 800 ka, resulting in one of the oldest and most complex coastal dune sequences in the world (Ellerton et al, 2020(Ellerton et al, , 2023.…”

Parabolic dune distribution, morphology and activity during the last 20 000 years: A global overview

“…They perform their function of sand storage, sometimes contain large reserves of groundwater, and act as a shelter for wildlife and endemic plant species, favouring the general sustainability of ecosystems (Kellerlynn, 2012; Pye & Tsoar, 2008). The development of the Great Barrier Reef made possible by the formation of coastal parabolic dunes on Fraser Island is one striking example of their essential role (Ellerton et al, 2022). Coastal parabolic dunes are also natural and aesthetic recreation areas that provide protection against sea level rise, tsunamis, storm surges, and floods (Gares et al, 1979; Psuty & Rohr, 2000).…”

Sea surface temperatures governed the development and longevity of the Great Barrier Reef

“…2). It was therefore argued that environmental factors other than temperature were responsible for initiating the GBR growth 9,10 . On the other hand, planktonic foraminiferal Mg/Ca-derived SST records from Site MD06-3018 in the southeastern Coral Sea (Fig.…”

“…It has been suggested that this extended period of warmth and higher sea levels led to the establishment of the GBR 40 . This was previously rejected because the U K 37' data did not show a particularly warm interglacial 8,9,16 . MIS 11 in the ODP 820 TEX86 H record, though not the warmest interglacial, is the first of the interglacials to have SSTs near 30°C and is about 1°C warmer than MIS 13 and MIS 9 (Fig 2).…”