Geological note: Igneous and sedimentary rocks dredged from the northern Macquarie Ridge, Southern Ocean

Created 17/10/2025

Updated 17/10/2025

Altered basalt, dolerite and gabbro have been dredged from a previously unsampled portion of the Macquarie Ridge (47o-48° S), using the commercial fishing vessel Amaltal Explorer. These rocks are petrographically and geochemically similar to mafic-ultramafic volcanic and plutonic suites of MORB-like petrological affinity, collected along the ridge between 49° and 58° S by previous investigators. The northernmost part of the Macquarie Ridge (Puysegur Bank) is thus geologically related to the rest of the ridge, even though it is bathymetrically part of the New Zealand continental shelf. Sedimentary rocks dredged from 47o-48° S were derived from both oceanic Macquarie Ridge and continental New Zealand sources. There is no evidence of subduction-related magmatism along any part of the Macquarie Ridge.

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Field Value
Title Geological note: Igneous and sedimentary rocks dredged from the northern Macquarie Ridge, Southern Ocean
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/1274a490-a40c-4e25-bd1d-df850f72efb7
Contact Point
Geoscience Australia Data
clientservices@ga.gov.au
Reference Period 20/04/2018
Geospatial Coverage Australia
Data Portal Geoscience Australia

Data Source

This dataset was originally found on Geoscience Australia "Geological note: Igneous and sedimentary rocks dredged from the northern Macquarie Ridge, Southern Ocean". Please visit the source to access the original metadata of the dataset:
https://ecat.ga.gov.au/geonetwork/srv/eng/csw/dataset/geological-note-igneous-and-sedimentary-rocks-dredged-from-the-northern-macquarie-ridge-souther1