Igneous and Sedimentary Rocks Dredged from the Northern Macquarie Ridge

Altered basalt, dolerite, and gabbro samples were dredged from a previously unsampled portion of the Macquarie Ridge (47°-48° S) using the commercial fishing vessel Amaltal Explorer. The rocks show petrographic and geochemical similarity to MORB-like suites found further south along the ridge. Sedimentary rocks from the same area indicate mixed oceanic and continental New Zealand sources, with no evidence of subduction-related magmatism.

Use Cases

• Petrological classification of dredged rock samples based on described mineralogy and geochemistry.
• Tectonic analysis of the Macquarie Ridge based on the absence of subduction-related magmatism.
• Provenance studies of sedimentary rocks based on mixed oceanic and continental sources.
• Geochemical comparison of mafic-ultramafic suites along the Macquarie Ridge latitude gradient.

Strengths

• Focuses on a previously unsampled geographic region (47°-48° S on the Macquarie Ridge).
• Provides petrographic and geochemical comparison to known suites from 49° to 58° S.
• Includes analysis of both igneous and sedimentary rock types from the same dredge operation.

Limitations

• Row count is unknown, which may limit suitability assessment.
• Column-level documentation is absent; field semantics must be inferred after download.
• Data may reflect geographic bias inherent to the specific dredge location.

Provenance

Source

Australian Ocean Data Network

Collection Method

Dredging operations conducted from the commercial fishing vessel Amaltal Explorer.

Freshness

Last updated 2026-06-05 06:04:39.609605; freshness should be verified.

Geography

Northern Macquarie Ridge, Southern Ocean (47°-48° S).