학술논문

Development of a Training Set of Contemporary Salt-Marsh Foraminifera for Late Holocene Sea- Level Reconstructions in southeastern Australia
Document Type
article
Source
Open Quaternary, Vol 7, Iss 1 (2021)
Subject
relative sea level
new south wales
tasmania
microfossil
multivariate analyses
transfer function
Human evolution
GN281-289
Prehistoric archaeology
GN700-890
Paleontology
QE701-760
Language
English
ISSN
2055-298X
Abstract
We collected contemporary foraminiferal training sets from two salt marshes to enable more precise and accurate proxy historical sea-level reconstructions from southeastern Australia. Combined with an existing training set from Tasmania, this new regional set consists of 112 samples and 16 species of foraminifera, of which 13 are agglutinated. Cluster analyses group the regional training set into a high–elevation cluster, dominated by 'Trochamminita salsa', a mid–elevation cluster, dominated by 'Entzia macrescens' and 'Trochammina inflata', and a mid–low elevation cluster dominated by Miliammina fusca and tidal-flat species. We develop transfer functions using local and regional training sets and assess their performance. Our resulting site-specific and chosen regional models are capable of predicting sea level with decimetre-scale precision (95% confidence intervals of 0.12–0.22 m). These results are comparable to other examples from around the world. When developing regional training sets, we advocate that the similarity in the environmental settings (particularly salinity) should be assessed as an alternative way of grouping sites, rather than simply using spatial proximity. We compare our findings with global results and conclude that salt marshes along microtidal coasts yield models with the lowest vertical uncertainties. Studies with the lowest uncertainties are located in the western Pacific and the western Atlantic, whereas those from the eastern Atlantic generally have larger tidal ranges and carry larger vertical uncertainties. Our models expand the existing region available for sea-level reconstruction and can be used to generate new late Holocene sea-level reconstructions across southeastern Australia.