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Continental Shelf Record of the East Antarctic Ice Sheet Evolution: Seismo-stratigraphic Evidence from the George V Basin

Created 16/10/2025

Updated 16/10/2025

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The late Quaternary ice sheet/ice shelf extent in the George V Basin (East Antarctica) has been reconstructed through analyses of Chirp sub-bottom profiles, integrated with multi-channel seismic data and sediment cores. Four glacial facies, related to the advance and retreat history of the glaciated margin, have been distinguished: Facies 1 represents outcrop of crystalline and sedimentary rocks along the steep inner shelf and comprises canyons once carved by glaciers; Facies 2 represents moraines and morainal banks and ridges with a depositional origin along the middle-inner shelf; Facies 3 represents glacial flutes along the middle-outer shelf; Facies 4 is related to ice-keel turbation at water depths <500 m along the outer shelf. A sediment drift deposit, located in the NW sector of the study area, partly overlies facies 2 and 3 and its ground-truthing provides clues to understanding their age. We have distinguished: a) an undisturbed sediment drift deposit at water depth >775 m, with drape/sheet and mound characters and numerous undisturbed sub-bottom sub-parallel reflectors (Facies MD1); b) a fluted sediment drift deposit at water depth <775 m, showing disrupted reflectors and a hummocky upper surface (Facies MD2). Radiocarbon ages of sediment cores indicate that the glacial advance producing facies MD2 corresponds to the Last Glacial Maximum (LGM) and that during the LGM the ice shelf was floating over the deep sector of the basin, leaving the sediment drift deposit undisturbed at major depths (Facies MD1). This observation further implies that: a) glacial facies underneath the sediment drift were the result of a grounding event older than the LGM, b) this sector of the East Antarctic fringe was sensitive to sea-level rise at the end of the LGM; thus potentially contributing to meltwater discharge during the last deglaciation.

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Field Value
Title Continental Shelf Record of the East Antarctic Ice Sheet Evolution: Seismo-stratigraphic Evidence from the George V Basin
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/a59101eb-dfdc-4a51-916f-2de56a73b440
Contact Point
Geoscience Australia Data
clientservices@ga.gov.au
Reference Period 22/04/2018
Geospatial Coverage
Map data © OpenStreetMap contributors
{
  "coordinates": [
    [
      [
        142.0,
        -67.5
      ],
      [
        146.5,
        -67.5
      ],
      [
        146.5,
        -65.5
      ],
      [
        142.0,
        -65.5
      ],
      [
        142.0,
        -67.5
      ]
    ]
  ],
  "type": "Polygon"
}
Data Portal Geoscience Australia

Data Source

This dataset was originally found on Geoscience Australia "Continental Shelf Record of the East Antarctic Ice Sheet Evolution: Seismo-stratigraphic Evidence from the George V Basin". Please visit the source to access the original metadata of the dataset:
https://ecat.ga.gov.au/geonetwork/srv/eng/csw/dataset/continental-shelf-record-of-the-east-antarctic-ice-sheet-evolution-seismo-stratigraphic-evidenc