Intraplate Volcanism and Mantle Dynamics in Eastern Australia

Intraplate volcanic activity across eastern Australia is expressed in a series of Cenozoic volcanic provinces that extend over 2 000 km along the Australian continent. These provinces comprise age-progressive chains of central volcanoes and age-independent lava fields, reflecting diverse mantle–lithosphere interactions. Origin hypotheses have evolved from simple plume models to include edge-driven convection and shear-driven upwelling at lithospheric steps, lateral variations in plate thickness and dynamic support of topography. Geophysical imaging, geochemical thermobarometry and geochronology collectively suggest that mantle temperature anomalies, lithospheric thinning and compositional heterogeneity all contribute to melt generation. The northward drift of Australia relative to mantle reference frames has led to systematic volcanic tracks aligned with plume conduits, while localised upwelling at cratonic margins generates scattered fields of basaltic flows. This interplay of deep-seated plumes, plate-driven flow and lithospheric architecture not only shapes eastern Australia’s volcanic record but also informs models of intraplate magmatism and global mantle convection.

Research from Nature Portfolio

Recent magnetotelluric studies have defined a conductive anomaly beneath the Newer Volcanics Province, aligning with a pronounced step in the lithosphere–asthenosphere boundary at depths of 20–40 km. Moderate resistivity reductions indicate fluid-catalysed alteration of the mid-lower crust and pockets of partial melt (1.2–3.6 %), supporting a hybrid model in which edge-driven convection at cratonic margins and shear-driven upwelling by plate motion combine to generate volcanism. This work refines the spatial relationship between lithospheric discontinuities and magmatic upwelling, demonstrating that rheological contrasts in the lithosphere can localise melt production without requiring deep, stationary plumes alone.

Intraplate Volcanism and Mantle Dynamics in Eastern Australia publication trend

The graph below shows the total number of articles in intraplate volcanism and mantle dynamics in eastern australia across all publications each year (not limited to Nature Index journals).

Technical terms

Magnetotellurics: A geophysical method that measures natural electromagnetic fields to map subsurface electrical resistivity.

Edge-driven convection: Mantle upwelling induced by lateral contrasts in lithospheric thickness at cratonic boundaries.

Shear-driven upwelling: Asthenospheric ascent provoked by lithospheric motion and shear stresses.

Laborosphere-asthenosphere boundary (LAB): The transition zone between the rigid lithospheric plate and the ductile underlying asthenosphere.

Mantle plume: A buoyant, hot column of deep mantle material rising towards the lithosphere, often generating age-progressive volcanic chains.

Thermobarometry: Geochemical techniques used to estimate the pressure and temperature conditions of mineral equilibration.

References

1. Magnetotelluric support for edge-driven convection and shear-driven upwelling in the Newer Volcanics Province. Scientific Reports (2023).
2. Animated reconstructions of the Late Cretaceous to Cenozoic northward migration of Australia, and implications for the generation of east Australian mafic magmatism. Geosphere (2017).
3. Thermal Structure of Eastern Australia's Upper Mantle and Its Relationship to Cenozoic Volcanic Activity and Dynamic Topography. Geochemistry Geophysics Geosystems (2021).
4. Plumbing System Architecture of Late-Stage Hotspot Volcanoes in Eastern Australia. Journal of Petrology (2022).