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

Late Early Miocene (~16 Ma) to Pliocene geological data from two submarine volcanic cones on the northeastern Lord Howe Rise, collected via multibeam sonar and dredging by the Australian Ocean Data Network. The dataset includes information on rock lithology, micropaleontology from interbedded micrites, and chemical analysis of ferromanganese crusts up to 7 cm thick. It was last updated on 2026-06-23.

Use Cases

• Modeling intraplate hotspot-type magmatism and seamount distribution based on gravity highs and crustal thickness described.
• Analyzing ferromanganese crust growth rates and hydrothermal influence based on reported Mn:Fe ratios and 3 mm/m.y. average growth.
• Correlating volcanic events with paleoceanographic conditions using the cool-water to warm-water foraminifera transition mentioned in the micrite record.
• Predicting fields of small volcanic seamounts in similar geological settings using the described correspondence with gravity anomalies.

Strengths

• Includes specific geochemical data for ferromanganese crusts, such as copper (<0.08 wt%), nickel (<0.65%), and cobalt (<0.25%) content.
• Provides precise temporal constraints from micropaleontology, indicating formation in the Early Miocene (~16 Ma) and later infillings.
• Contains detailed lithological descriptions of dredged rocks, including hyaloclastites, basalt, and clinopyroxene compositions.

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 data_gov_au, focusing on a specific region of the Lord Howe Rise.

Provenance

Source

Australian Ocean Data Network

Collection Method

Multibeam sonar swath-mapping and rock dredging from two submarine volcanic cones.

Time Range

Late Early Miocene (~16 Ma) to Pliocene

Freshness

Last updated 2026-06-23 05:39:37.296052; freshness should be verified.

Geography

Northeastern Lord Howe Rise, at approximately 23-24°S, 120 km apart