Changes in ideas of age of certain beds in the Australian Tertiaries

Created 16/10/2025

Updated 16/10/2025

Drastic changes in ideas of the age of some of the marine Tertiary deposits in Australia have been necessary in the last few years. The recognition of Eocene over a wide area in south-eastern Australia is the result of considerable detailed mapping of deposits in south-western Victoria and the subsequent detailed investigation of the sediments for microfaunas. The discovery of the Eocene foraminiferal genus Hantkenina at different localities in south-eastern Australia has been an important factor in bringing about the recognition of the Eocene. The discovery of Hantkenina at Bird Rock, Torquay, Victoria, the type locality for the Janjukian Stage of Victorian Tertiary stratigraphy, confirms an Eocene age for beds which had previously been placed in the Upper Oligocene or the Miocene. The type section for the "Anglesean Stage" at Anglesea, west of Torquay, which has been regarded as Oligocene, is now placed in the Middle Eocene. The beds at Anglesea stratigraphically underlie those containing Hantkenina at Torquay. At least 4,000 feet of the Middle Eocene beds have been proved in bores. In western Victoria it is quite probable that Lower Eocene to Paleocene beds exist. There is still doubt as to whether definite marine Oligocene beds exist in Australia. Certain non-marine deposits thought to be of Lower Oligocene age are now Middle Miocene. Ideas of age of the beds in the Upper Tertiary have undergone little change. The calcareous sandstones of the Adelaide Basin in South Australia are regarded as Lower Pliocene rather than Middle or Upper Pliocene of certain authors.

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Field Value
Title Changes in ideas of age of certain beds in the Australian Tertiaries
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/0ceac19c-6328-4f78-b73d-194fca7e88cb
Contact Point
Geoscience Australia Data
clientservices@ga.gov.au
Reference Period 22/04/2018
Geospatial Coverage
Map data © OpenStreetMap contributors
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      ],
      [
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      ],
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      ],
      [
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      ],
      [
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      ]
    ]
  ],
  "type": "Polygon"
}
Data Portal Geoscience Australia

Data Source

This dataset was originally found on Geoscience Australia "Changes in ideas of age of certain beds in the Australian Tertiaries". Please visit the source to access the original metadata of the dataset:
https://ecat.ga.gov.au/geonetwork/srv/eng/csw/dataset/changes-in-ideas-of-age-of-certain-beds-in-the-australian-tertiaries