Miocene Volcanic Seamounts on Northern Lord Howe Rise: Lithology, Age, and Crust Chemistry

The northeastern Lord Howe Rise, a submerged ribbon continent, contains small submarine volcanic cones revealed by multibeam sonar swath-mapping. Dredging of two cones 120 km apart yielded volcanic rocks, interbedded micrites, and ferromanganese crusts up to 7 cm thick. The dataset, hosted by the Australian Ocean Data Network, was last updated in May 2026.

Use Cases

• Modeling the genesis of small volcanic seamounts based on gravity highs and shallow continental basement.
• Analyzing ferromanganese crust growth rates and chemistry based on reported thicknesses and elemental compositions.
• Dating volcanic and sedimentary sequences based on micropaleontological evidence from foraminifera in micrites.
• Correlating clinopyroxene compositions to undersaturated intraplate basanitic mafic lavas for petrological classification.

Strengths

• Includes specific geochemical measurements, such as copper not exceeding 0.08 wt %, nickel 0.65%, and cobalt 0.25%.
• Provides temporal constraints, with the oldest micrite dated to the late Early Miocene (~16 Ma).
• Contains precise spatial and bathymetric details, including cone locations at 23-24°S and water depths from 750 to 1150 m.

Limitations

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

Provenance

Source

Australian Ocean Data Network

Collection Method

Multibeam sonar swath-mapping and dredging operations.

Time Range

Miocene to Pliocene, with oldest material ~16 million years old.

Freshness

Last updated 2026-05 04 23:42:23.698875; freshness should be verified.

Geography

Northeastern Lord Howe Rise, at approximately 23-24°S.