Late Quaternary climate change in Australia's arid interior: Evidence from Kati Thanda-Lake Eyre

0560428 - GFÚ 2023 RIV GB eng J - Článek v odborném periodiku
Cohen, T. J. - Arnold, L. J. - Gázquez, F. - May, J.-H. - Marx, S. K. - Jankowski, N. R. - Chivas, A. R. - Garćia, A. - Cadd, H. - Parker, A. G. - Jansen, John D. - Fu, X. - Waldmann, N. - Nanson, G. C. - Jones, B. G. - Gadd, P.
Late Quaternary climate change in Australia's arid interior: Evidence from Kati Thanda-Lake Eyre.
Quaternary Science Reviews. Roč. 292, September (2022), č. článku 107635. ISSN 0277-3791. E-ISSN 1873-457X
Institucionální podpora: RVO:67985530
Klíčová slova: Lake Eyre * Kati Thanda * playa lake * arid * OSL * fluvial * lacustrine * gypsum * stable isotopes
Obor OECD: Physical geography
Impakt faktor: 4, rok: 2022
Způsob publikování: Omezený přístup
https://www.sciencedirect.com/science/article/pii/S0277379122002669

Williams Point is an iconic late Quaternary sedimentary sequence exposed at the southern margin of Madigan Gulf at Kati Thanda -Lake Eyre (KT-LE), Australia's largest lake. The-15 m high cliff outcrop includes 6 m of aeolian sediments, capping a-0.5 m beach/shoreline facies containing abundant Coxiella (aquatic gastropod) unconformably overlying 5-6 m of fluvio-lacustrine facies. The base of the outcrop and the playa floor comprises shallow and deeper water laminated lacustrine sediments. We re-examine the stratigraphic sequence using detailed excavations, micromorphological analysis and geochemical characterisation (X-ray fluorescence, X-ray diffraction, palaeoecology, stable isotope analysis of gypsum hydration water and biogenic carbonates, rare earth element analysis) and present a revised chronology using single-grain optically stimulated luminescence (OSL) within a Bayesian framework. Our new chronostratigraphic data generally supports previous interpretations for Williams Point, but crucially refines the timing of several of the key sedimentological units. A palaeoplaya, or oxidised shallow lake deposits, formed at 153 +/- 11 ka (175-131 ka, 95% C.I.) and the uppermost shallow water lacustrine facies at the base of the cliff was deposited at 131 +/- 9 ka (150-113 ka, 95% C.I.). An unconformity separates these sediments from the overlying fluvio-lacustrine phase, securely constrained (with eight OSL samples) to 86 +/- 4 ka (95-78 ka, 95% C.I.). The isotopic composition of the palaeolake water (318O and 3D), reconstructed from the hy-dration water of syndepositional gypsum formed in-situ in these fluvio-lacustrine sediments, indicates wetter conditions at 95-78 ka than at ca. 232-131 ka. Based on the provenance analysis these fluvio-lacustrine and lacustrine sediments were sourced from the northern catchments within the Lake Eyre basin but with an additional contribution from the northern Flinders Ranges. These results bring fresh perspectives to a site that has held a heavy sway over previous views of the Quaternary history of Australia's arid zone.
Trvalý link: https://hdl.handle.net/11104/0333411