Independent Bayesian age modelling in subtropical wetlands to assess the influence of global climate drivers across Australia
Loading...
Date
2018-12-10
Journal Title
Journal ISSN
Volume Title
Publisher
Australasiain Quaternary Association Inc
Abstract
Rigorously dated, continuous sedimentological records capturing multiple glacial/interglacial cycles are important for evaluating the magnitude and range of drivers influencing ecosystem change in Australia. Multi-proxy palaeoenvironmental reconstructions are commonly used to identify changes in long-term environmental conditions, particularly when exploring the climatic backdrop to Australia’s large scale faunal extinctions. However, interpretations of these records may not be straightforward as local and regional climate signals are often mixed in proxy records. In order to evaluate whether improved temporal constraint can help with differentiating such convoluted signals, thereby increasing the confidence placed in the role of teleconnections across the Southern Hemisphere, we present a comprehensively dated 12.7 m (basal age ~130 ka) wetland core consisting of 21 optically stimulated luminescence and seven radiocarbon ages from North Stradbroke Island. The amalgamation of stratigraphic information and independent age constraints within a Bayesian framework, highlights the complex depositional history of Welsby Lagoon between late MIS 5 and MIS 2. ITRAX core scanning data reveals fluctuations in elemental abundance through time, in particular the decrease in the amount of aeolian sediment following MIS 3. Variability is attributed to regional environmental regime changes controlled by global drivers, including Heinrich events, and the influence of moisture across mainland Australia. The comprehensive dating approach undertaken at Welsby Lagoon highlights the role that the terrestrial palaeoenvironmental records of North Stradbroke Island can play in assessing long-term climate drivers across continental Australia, without relying exclusively on isotopic tuning of remote (ice core or marine) records. © The Authors
Description
Keywords
Age estimation, Australia, Wetlands, Aquatic ecosystems, Surface waters, Glaciers, Quaternary period, Environment, Southern Hemisphere, Carbon 14
Citation
Lewis, R., Tibby, J, Arnold, L., Barr, C., Marshall, J., McGregor. G., & Gadd, P. (2018). Independent Bayesian age modelling in subtropical wetlands to assess the influence of global climate drivers across Australia. Paper presented at the AQUA Biennial Conference, Canberra, 10-14 December 2018, (pp. 44). https://aqua.org.au/wp-content/uploads/2019/10/AQUA-2018-Program.pdf