Volcanic Processes in Oceanic Plateaus

Volcanic processes in oceanic plateaus are dominated by high-volume, often short-lived eruptions linked to mantle plume activity and interactions with mid-ocean ridges. Magma ascent can occur through extensive dike swarms and feeder conduits that produce thick sequences of pillow basalts and massive flows, contributing to anomalously thickened crust. Underplating of residual melt at the crust–mantle boundary further modifies lithospheric structure, while subsequent tectonic extension and segmentation can fracture plateaux into discrete blocks. Following emplacement, extensive degassing and interactions with seawater influence ocean chemistry, potentially driving oceanic anoxic events. Detailed studies of plateau evolution have global significance for understanding large-scale carbon cycling, marine resource distribution and the dynamics of intraplate tectonics.

Research from Nature Portfolio

Recent studies have employed combined Pb-Os-C isotopic analyses to constrain the timing of explosive submarine eruptions and ash deposition during the formation of the Ontong Java Nui event. These data reveal a clear lead isotope signature coinciding with seawater δ13C and 187Os/188Os shifts immediately prior to the onset of an oceanic anoxic event, indicating rapid, intensive volcanic degassing. Complementary geochemical and 40Ar-39Ar age determinations on dredged basalts from the eastern margin of Ontong Java Plateau bridge compositional and temporal gaps between the Ontong Java, Manihiki and Hikurangi fragments. New age brackets of c. 96–116 Ma and 67–68 Ma reinforce the hypothesis of a once-contiguous super-plateau and illuminate heterogeneity in mantle source components over successive eruptive phases.

Research from all publishers

Marine seismic surveys across the Hikurangi Plateau margin have mapped five major seamount edifices and revealed a reduction in crustal thickness from 11 ± 1 km in the south to 7–8 km in the north. This heterogeneity is attributed to rifting from a paired plateau and influences subduction zone geometry and upper-plate deformation along New Zealand’s margin. High-resolution bathymetric mapping of southern Shatsky Rise has exposed subtle segmentation of Tamu Massif into multiple sub-rises formed by eruptions along a jumping triple junction, with secondary volcanic cones aligned to spreading-ridge parallel faults and evidence of extensive sediment mass wasting. Numerical geodynamic models further demonstrate that slab-pull forces transmitted through ocean lithosphere can induce syn-drift extensional deformation of oceanic plateaux, overturning the paradigm of rigid plate behaviour away from subduction zones.

Volcanic Processes in Oceanic Plateaus publication trend

The graph below shows the total number of articles in volcanic processes in oceanic plateaus across all publications each year (not limited to Nature Index journals).

Technical terms

Oceanic plateau: A region of thickened oceanic crust formed by voluminous basaltic eruptions, often exceeding normal seafloor thickness by several kilometres.

Large Igneous Province (LIP): An extensive accumulation of igneous rock emplaced over a short geological interval, typically associated with mantle plume activity.

Mantle plume: A buoyant, hot column of deep-mantle material that ascends to the base of the lithosphere, initiating high-degree melting.

Underplating: The accumulation of magmatic material at the crust–mantle boundary, contributing to crustal thickening and modification of lithospheric structure.

Isotopic signature: The characteristic ratios of stable or radiogenic isotopes in a rock or mineral, used to trace magma sources and differentiation processes.

References

1. Brief and intensive volcanic emissions from Ontong Java Nui heralded Oceanic Anoxic Event 1a. Communications Earth & Environment (2024).
2. New evidence for the Ontong Java Nui hypothesis. Scientific Reports (2023).
3. Heterogeneous Crustal Structure of the Hikurangi Plateau Revealed by SHIRE Seismic Data: Origin and Implications for Plate Boundary Tectonics. Geophysical Research Letters (2023).
4. Improved High‐Resolution Bathymetry Map of Tamu Massif and Southern Shatsky Rise and Its Geologic Implications. Journal of Geophysical Research: Solid Earth (2022).
5. Syn‐Drift Plate Tectonics. Geophysical Research Letters (2024).