From Australian Oceans Data Network
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Coring Analyses of Cores from Near Shore Sites in the Vestfold Hills

Created 24/06/2025

Updated 24/06/2025

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The sedimentological, chemical and isotopic characteristics of sediment cores from three slightly saline to hypersaline lakes (Highway, Ace and Organic Lakes) and two marine inlets (Ellis Fjord and Taynaya Bay) in the Vestfold Hills, Antarctica have been examined. Sections of the cores deposited in marine environments are characterised by uniform, regularly laminated, fine grained, organic-rich sediments, with uniform organic delta 13C values (-18.0 to 19.4 ppt vs. PDB) and sulfur contents. In contrast, sediments deposited in lacustrine environments are extremely heterogeneous, varying from finely laminated mat-like sequences to poorly sorted clastic-rich sediments. Authigenic monohydrocalcite and aragonite occur in some lake sediments. The delta 13C values of organic matter in the lacustrine sediments exhibit an extremely wide range (-10.5 to -25.3 ppt) that can be related to variations in physico-chemical conditions in the lake waters. Strongly negative organic-delta 13C values coupledwith high sulfur contents are indicative of an anoxic zone in the overlying lake waters, whereas less negative organic-delta 13C values coupled with low sulfur contents are indicative of well-mixed oxic conditions. Particularly high organic-delta 13C values result during high levels of microbial activity in the lakes, due to high rates of photosynthetic CO2 fixation. The large shifts in organic-delta 13C are not necessarily accompanied by any change in macroscopic sedimentological characteristics, illustrating the utility if isotopic investigations in these environments. The delta 13C composition of authigenic carbonate in hypersaline Organic Lake sediments provides a record of changes in palaeoproductivity, while the delta 18O of the carbonate provides information on rates of meltwater input and evaporation in the lake. 14C-dating suggests that Highway Lake was isolated from the sea by isostatic uplift at least 4600 years before present (BP) whereas Organic Lake was isolated at approximately 2700 years BP. Apparent emergence rates calculated from the 14C ages range from 1.0 to 2.1 mm per year. The 'reservoir effect' in the lacustrine and marine environments is variable, but probably does not exceed ~ 1000 years in any of the lakes examined.

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Field Value
Title Coring Analyses of Cores from Near Shore Sites in the Vestfold Hills
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/0c4afa1b-6c51-491a-8d3b-05d62e9ecf30
Contact Point
Australian Ocean Data Network
metadata@aad.gov.au
Reference Period 01/09/1978 - 31/12/1987
Geospatial Coverage
Map data © OpenStreetMap contributors
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  "coordinates": [
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        78.1878,
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      ],
      [
        78.2923,
        -68.603
      ],
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        78.2923,
        -68.4718
      ],
      [
        78.1878,
        -68.4718
      ],
      [
        78.1878,
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      ]
    ]
  ],
  "type": "Polygon"
}
Data Portal Australian Oceans Data Network

Data Source

This dataset was originally found on Australian Oceans Data Network "Coring Analyses of Cores from Near Shore Sites in the Vestfold Hills". Please visit the source to access the original metadata of the dataset:
https://catalogue.aodn.org.au/geonetwork/srv/eng/csw/dataset/coring-analyses-of-cores-from-near-shore-sites-in-the-vestfold-hills