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

Two submarine volcanic cones, 120 km apart on the Lord Howe Rise, were dredged at water depths of 750-900 m. Volcanic rocks are predominantly altered hyaloclastites with minor basalt, and ferromanganese crusts up to 7 cm thick were analyzed. The dataset, from Geoscience Australia, includes lithological descriptions, micropaleontological age constraints (~16 Ma), and geochemical data on crust composition and growth rates.

Use Cases

• Modeling intraplate hotspot magmatism based on cone alignment and gravity high correlations mentioned in the description.
• Analyzing ferromanganese crust growth rates and hydrothermal influence based on reported Mn:Fe ratios and chemical variations.
• Dating submarine volcanic events using the described micropaleontological evidence from interbedded micrites.
• Correlating volcanic seamount fields with crustal thickness variations as suggested by the discussion of magma dissipation in continental crust.

Strengths

• Includes specific geochemical measurements, such as copper (<0.08 wt%), nickel (<0.65%), and cobalt (<0.25%) content in crusts.
• Provides precise spatial and bathymetric context, including cone depths (750 m, 900 m) and separation (120 km).
• Contains age constraints derived from foraminifera, indicating a late Early Miocene (~16 Ma) origin.

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

Geoscience Australia Data

Collection Method

Multibeam sonar swath-mapping and dredge sampling of submarine volcanic cones.

Time Range

Late Early Miocene (~16 Ma) to Pliocene, based on micropaleontology.

Freshness

Last updated 2026-04-30 15:16:36.016749; freshness should be verified.

Geography

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