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Oxygen-isotope records, age-model results and sedimentation rates of core MD88-779

Created 23/06/2025

Updated 23/06/2025

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Core MD88-779 was taken during the 1988 French ASPARA IV cruise in the South East Indian Ocean aboard the Marion DuFresne. The core was situated on the South Tasman Rise (47º50.690S, 146º32.750E) at a depth of 2260m. Although the core recovered was 6.7m long, only the top 2.6m were studied as preliminary investigations had indicated that this section covered the last two glacial cycles. Isotopic analysis was performed on tests of the benthic foraminifera Cibicidoides wuellerstorfi. The record contains two climatic cycles that reach into isotope-stage 7. The benthic isotope curve of core MD88-779, however, shows a melding of isotopic stages 3-5, which are difficult to separate with depth. The age-model is derived through comparison with the benthic SPECMAP stack of Martinson et al. (1987). The core covers 200kyr over 260cm, and thus has a low sedimentation rate. It also shows a reduction of sedimentation from the Holocene rates to that of the last glacial (oxygen-isotope stage 2). The complete loss of a diatom record at 170cm and 210/220cm in the core is extremely unusual. The diatom signal is interpreted as having been removed by increased water mass velocity, extreme post-depositional silica dissolution or decreased productivity. There is no sedimentological evidence from the core which provides further interpretation.

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Additional Info

Field Value
Title Oxygen-isotope records, age-model results and sedimentation rates of core MD88-779
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/fa4a0de9-f4df-40a2-a742-dec72b3794b1
Contact Point
Australian Ocean Data Network
patrick.dedeckker@anu.edu.au
Reference Period 01/01/1988 - 01/01/1988
Geospatial Coverage
Map data © OpenStreetMap contributors
{
  "coordinates": [
    [
      [
        146.5,
        -48.0
      ],
      [
        147.0,
        -48.0
      ],
      [
        147.0,
        -47.5
      ],
      [
        146.5,
        -47.5
      ],
      [
        146.5,
        -48.0
      ]
    ]
  ],
  "type": "Polygon"
}
Data Portal Australian Oceans Data Network

Data Source

This dataset was originally found on Australian Oceans Data Network "Oxygen-isotope records, age-model results and sedimentation rates of core MD88-779". Please visit the source to access the original metadata of the dataset:
https://catalogue.aodn.org.au/geonetwork/srv/eng/csw/dataset/oxygen-isotope-records-age-model-results-and-sedimentation-rates-of-core-md88-7791