EGU22-6571, updated on 28 Mar 2022
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Parallel volcanic chains generated by plume-slab interaction

Ben Mather1, Maria Seton1, Simon Williams1,2, Joanne Whittaker3, Rebecca Carey4, Maëlis Arnould5, Nicolas Coltice6, Angus Rogers7, Saskia Ruttor7, and Oliver Nebel7
Ben Mather et al.
  • 1The University of Sydney, School of Geoscience, Sydney, Australia (
  • 2School of Geoscience, Northwest University, Xi’an, China
  • 3Institute of Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7001, Australia
  • 4School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia
  • 5University of Lyon, UCBL, ENSL, UJM, CNRS, Laboratoire de Géologie de Lyon – Terre, Planètes, Environnement, LGL-TPE, F-69622, Villeurbanne, France
  • 6Laboratoire de Géologie, École Normale Supérieure, CNRS UMR 8538, PSL Research University, 24 rue Lhomond, 75005 Paris, France
  • 7School of Earth, Atmosphere and Environment, Monash University, Clayton, VIC 3800, Australia

Deep mantle plumes are buoyant upwellings rising from the Earth’s core-mantle boundary to its surface, and describing most hotspot chains. Mechanisms to explain dual chains of hotspot volcanoes for the Hawaiian-Emperor and Yellowstone chains fail to explain the geochemical similarity and large distances between contemporaneous volcanoes of the Tasmantid and Lord Howe chains in the SW Pacific. Using numerical models of mantle convection, we demonstrate how slab-plume interaction can lead to sustained plume branching over a period of >40 million years to produce parallel volcanic chains that track plate motion. We propose a three-part model: first, slabs stagnate in the upper mantle, explaining fast upper mantle P-wave velocity anomalies; second, deflection of a plume conduit by a stagnating slab splits it into two branches 650-900 km apart, aligning to the orientation of the trench axis; third, plume branches heat the stagnating slab causing partial melting and release of volatiles which percolate to the surface forming two contemporaneous volcanic chains with slab-influenced EM1 signatures. Our results highlight the critical role of long-lived subduction on the evolution and behaviour of intraplate volcanism.

How to cite: Mather, B., Seton, M., Williams, S., Whittaker, J., Carey, R., Arnould, M., Coltice, N., Rogers, A., Ruttor, S., and Nebel, O.: Parallel volcanic chains generated by plume-slab interaction, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6571,, 2022.


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