Holocene sea-level change and coastal landscape evolution in the southern Gulf of Carpentaria, Australia

Abstract

A revised Holocene sea-level history for the southern Gulf of Carpentaria is presented based on new data from the South Wellesley Archipelago and age recalibration of previous research. Results confirm that rising sea levels during the most recent post-glacial marine transgression breached the Arafura Sill ca. 11,700 cal. yr BP. Sea levels continued to rise to ca. -30 m by 10,000 cal. yr BP, leading to full marine conditions. By 7700 cal. yr BP, sea-level reached present mean sea-level (PMSL) and continued to rise to an elevation of between 1.5 m and 2 m above PMSL. Sea level remained ca. + 1.5 between 7000 and 4000 cal. yr BP, followed by rapid regression to within ± 0.5 m of PMSL by ca. 3500 cal. yr BP. When placed into a wider regional context results from this study show that coastal landscape evolution in the tropical north of Australia was not only dependent on sea-level change but also show a direct correlation with Holocene climate variability. Specifically, the formation and preservation of beach-rock deposits, intertidal successions, beach and chenier ridge systems hold valuable sea-level and Holocene climate proxies that can contribute to the growing research into lower latitude Holocene sea-level and climate histories.

Fine-scale population structure and evidence for local adaptation in Australian giant black tiger shrimp (Penaeus monodon) using SNP analysis

“…Upwelling of deep cold water along the north-western Australian coastline, which has existed since the Late Miocene period, is one biogeographical barrier known to prevent gene flow between Western Australia and other Australian regions [54]. Moreover, repeated declines in sea surface levels of 100-140 m during the Pleistocene caused biogeographic isolation between northern and eastern Australia due to repeated emergence of land bridges between northern Australia, Torres Strait, and New Guinea [55][56][57][58]. Similar patterns in genetic structure between Australian populations have been observed for other marine species such as Australian Spanish mackerel (Scomberomorus commerson) [59], mud crab (Scylla serrata) [60], brown tiger prawn (Penaeus esculentus) [61], and barramundi (Lates calcarifer) [62].…”

Aboriginal marine subsistence foraging flexibility in a dynamic estuarine environment: The late development of Tin Can Inlet (southeast Queensland) middens revisited

“…A range of evidence from the Great Barrier Reef indicates that rising sea levels reached current levels ~8000 years ago and continued rising a further 1.0-1.5m which were maintained between ~7000 and ~4000 years ago and then, with some fluctuations, fell back to modern levels, especially over the past 1000 years (Lewis et al 2013:126-127; see also Sloss et al 2018). In Moreton Bay in southeast Queensland, sea level appears to have been at least 1.1m higher between >c.6700 and c.5700 years ago, after which it started to fall to modern levels (Cooley 2017:122;Leonard et al 2013;Major 2012), possibly mostly within the past 2000 years as indicated by progradation of beach ridges (Cotter 1996;Ward and Hacker 2006).…”

Extended residence times for foraminifera in a marine-influenced terrestrial archaeological deposit and implications for palaeoenvironmental reconstruction

“…The sandy beach ridge deposits overlie beachrock dated on a G. tumidum concreted into its surface to 5334 cal BP (Table 1, Figure 5). The beachrock comprises nearshore sediments indurated by precipitation and cementation of calcium carbonate during the most recent postglacial marine transgression as sea-level rose above present mean sea-level level (PMSL) to c.2 to 2.5m above PMSL by 7000 cal BP followed a sea-level highstand until c.2000 years ago (Reeves et al 2008;Sloss et al 2012;Lewis et al 2013). These ages indicate a >3000 year hiatus between the formation of the natural shelly-beach ridge and subsequent initiation of cultural occupation c.800 cal BP ( Figure 5).…”

“…Similarly, foraminifera samples recovered from Thundiy may have complex taphonomic histories that reflect the residence time of the dated specimens in the sedimentary system as a result of differential preservation among foraminifera in the intertidal zone. Production and deposition of foraminfera would have changed dramatically across the Holocene with sea-level rise peaking around Bentinck Island between 2 and 2.5 m above PMSL by 7000 cal BP followed a sea-level highstand until c.2000 years ago, resulting in the formation of beach rock and aeolinite, and the initiation of beach ridge, mudflats and mangrove swamp environments (Sloss et al 2012).…”

“…Preliminary radiocarbon ages from estuarine bivalves preserved below the modern claypan in transgressive and mangrove deposits east-southeast of Thundiy provide age determinations of 4108 to 6090 cal BP corresponding with the end of the most resent post-glacial marine transgression and Holocene sea-level highstand (Sloss et al 2012). These mid-Holocene transgressive and mangrove highstand deposits provide a reservoir locale for the local storage of foraminiferas before intermittent remobilisation and re-deposition over the mid-to-late Holocene (see also Woodroffe et al 2007;Woodroffe and Morrison 2001;Dawson et al 2014).…”