Please use this identifier to cite or link to this item: https://apo.ansto.gov.au/dspace/handle/10238/9537
Title: Late quaternary environmental change at Lake McKenzie, in subtropical eastern Australia: evidence from sedimentary carbon, nitrogen and biomarkers
Authors: Atahan, P
Heijnis, H
Le Métayer, P
Grice, K
Taffs, K
Hembrow, S
Dodson, JR
Keywords: Queensland
Lakes
Australia
Carbon
Nitrogen
Sedimentation
Sand
Coastal waters
Climates
Environment
Fossils
Carbon 14
Lipids
Algae
Issue Date: 13-Feb-2013
Publisher: Past Global Changes
Citation: Atahan, P., Heijnis, H., Le Métayer, P., Grice, K., Taffs, K., Hembrow S., & Dodson, J. (2013). Paper presented the Past Global Changes 4th Open Science Meeting, Goa, India 13-16 February 2013.
Abstract: Fraser Island is part of a large sand mass that extends along the subtropical coastline of south-eastern Queensland. The island is a World Heritage site, listed for its unique natural environment that includes numerous perched oligotrophic dune lakes and a diverse suite of coastal and subtropical vegetation communities. Here we present geochemical and microfossil information for a sediment core collected from Lake McKenzie, in the island’s centre. AMS 14C and 210Pb dating has been conducted and indicates a basal age of ca. 37,000 cal. BP. A hiatus in the sedimentary record is apparent at around 25 cm depth and spans the time period from ca. 18,280 to 13,990 cal yr BP. Elemental and stable isotope measurements of carbon and nitrogen in bulk organic matter, along with biomarker and compound specific carbon isotope analyses, show a clear shift in lake conditions appearing with the re-commencement of sediment accumulation following this hiatus. A marked decline in the abundance of microfossils of the green colonial algae Botryococcus, coincides with a distinct change in composition of Botryococcus derived lipids and a shift to more negative δ13C values of long chain odd n-alkane compounds. An increase in lake size around 13,990 cal yr BP is suggested by the recommencement of sediment accumulation at the site, and is presumably in response to increased effective precipitation. The lake McKenzie record provides a long-term perspective on changing environmental conditions in central Fraser Island.
Gov't Doc #: 9674
URI: http://apo.ansto.gov.au/dspace/handle/10238/9537
Appears in Collections:Conference Publications

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