From Geoscience Australia
JSON format icon JSON RDF format icon RDF ISO19115-3 XML

Late Proterozoic peralkaline intrusives of the Alligator Rivers region, Northern Territory

Created 16/10/2025

Updated 16/10/2025

JSON format icon JSON RDF format icon RDF ISO19115-3 XML

The Mudginberri and Maningkorrirr Phonolites in the Alligator Rivers region consist of swarms of discordant peralkaline dykes that intrude Archaean to late Early Proterozoic rocks. Samples have given a Rb-Sr isotopic age of 1316 Ma. The dykes are phonolitic in composition and typically porphyritic, containing alkali feldspar, nepheline, sodic pyroxene, and minor biotite and apatite. In some small globules of mostly alkali feldspar may be products of liquid immiscibility. The dykes intrude part of the stable North Australian Craton and may represent late differentiates of concealed alkaline magma, as there are no other alkaline intrusive rocks known in the region. Alternatively, they may have formed by incipient melting in the upper mantle and deep crust.

Files and APIs

Tags

Additional Info

Field Value
Title Late Proterozoic peralkaline intrusives of the Alligator Rivers region, Northern Territory
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/en/dataset/9686a210-ab51-4fdd-a7c1-9768433eab3d
Contact Point
Geoscience Australia Data
clientservices@ga.gov.au
Reference Period 20/04/2018
Geospatial Coverage
Map data © OpenStreetMap contributors
{
  "coordinates": [
    [
      [
        131.65,
        -14.22
      ],
      [
        134.29,
        -14.22
      ],
      [
        134.29,
        -11.99
      ],
      [
        131.65,
        -11.99
      ],
      [
        131.65,
        -14.22
      ]
    ]
  ],
  "type": "Polygon"
}
Data Portal Geoscience Australia

Data Source

This dataset was originally found on Geoscience Australia "Late Proterozoic peralkaline intrusives of the Alligator Rivers region, Northern Territory". Please visit the source to access the original metadata of the dataset:
https://ecat.ga.gov.au/geonetwork/srv/eng/csw/dataset/late-proterozoic-peralkaline-intrusives-of-the-alligator-rivers-region-northern-territory