Browsing by Author "Longmore, M"

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    Environmental change through the last glacial cycle at Fraser Island, subtropical Australia
    (International Union for Quaternary Research (INQUA), 2019-07-29) Kemp, J; Heijnis, H; Longmore, M; Gadd, PS; Spooner, NA; Questiaux, D
    Recent programs to extract detailed and longer records of Australia’s Pleistocene environments have produced a number of efforts to analyse long sedimentary sequences in the subtropical sand islands of Australia’s east coast. Echo Lake is a perched fen within ancient dune sands on Fraser Island at 25° S that provides a record of precipitation change over ~100 ka. A 12 metre core into the (now) ephemeral swamp revealed lacustrine sedimentation in a period of higher precipitation, followed by a transition to swamp sedimentation as water levels fell. The chronology, based on 14C and OSL ages, suggests parts of the record may be interrupted or lost owing to drying or burning of the surface. Here we present an updated OSL chronology together with pollen analysis and ITRAX-XRF proxies for palaeoenvironmental change over the last glacial cycle in subtropical Australia.
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    Sedimentation and vegetation change through the last glacial cycle at Echo Lake, Fraser Island
    (Australiasian Quaternary Association Inc., 2018-12-10) Kemp, J; Heijnis, H; Longmore, M; Gadd, PS; Spooner, NA; Questiaux, D
    Echo Lake is an ephemeral swamp perched above the groundwater table within the subtropical dunes of Fraser Island at 100 m above sea level. A 12 metre core was extracted in 1997-1998, with preliminary pollen analysis and dating suggesting the site preserved a palaeoenvironmental record beginning at 2 ka and spanning most of the last glacial cycle. However, the chronology has been problematic and sedimentation may have been interrupted or lost through drying and burning of the surface. Radiocarbon and optically stimulated luminescence (OSL) dating suggested an age for the base of the sedimentary sequence of at least 100 ka. Here we present a new chronology based on OSL on lake sediments together with ITRAX-XRF proxies for palaeoenvironmental change. © Author(s)