Journal article

Magnesium in subaqueous speleothems as a potential palaeotemperature proxy

Russell Drysdale, Isabelle Couchoud, Giovanni Zanchetta, Ilaria Isola, Eleonora Regattieri, John Hellstrom, Aline Govin, Polychronis C Tzedakis, Trevor Ireland, Ellen Corrick, Alan Greig, Henri Wong, Leonardo Piccini, Peter Holden, Jon Woodhead



Few palaeoclimate archives beyond the polar regions preserve continuous and datable palaeotemperature proxy time series over multiple glacial-interglacial cycles. This hampers efforts to develop a more coherent picture of global patterns of past temperatures. Here we show that Mg concentrations in a subaqueous speleothem from an Italian cave track regional sea-surface temperatures over the last 350,000 years. The Mg shows higher values during warm climate intervals and converse patterns during cold climate stages. In contrast to previous studies, this implicates temperature, not rainfall, as the principal driver of Mg variability. The depositional setting of the speleothem gives rise to Mg p..

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Awarded by Australian Research Council

Awarded by Australian Research Council Discovery Project

Funding Acknowledgements

We are grateful to the Gruppo Speleologico Lucchese for their assistance with the recovery of the CD3-1 drill core. This study was funded by Australian Research Council Discovery Project grants DP0773700 (to R.D., J.H. and G.Z.), DP110102185 (to R.D., J.W., J.H. and G.Z.) and DP160102969 (to R.D., J.W., G.Z., E.R. and P.T.). I.C. was the beneficiary of a research associate position funded under Australian Research Council Discovery Project DP0773700.