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Ridge subduction sparked reorganization of the Pacific plate-mantle system 60-50 million years ago

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posted on 2023-05-18, 08:32 authored by Seton, M, Flament, N, Joanne WhittakerJoanne Whittaker, Muller, RD, Gurnis, M, Bower, DJ
A reorganization centered on the Pacific plate occurred ~53-47 million years ago. A ‘topdown’ plate tectonic mechanism, complete subduction of the Izanagi plate, as opposed to a ‘bottom-up’ mantle flow mechanism, has been proposed as the main driver. Verification based on marine geophysical observations is impossible as most ocean crust recording this event has been subducted. Using a forward modeling approach, which assimilates surface plate velocities and shallow thermal structure of slabs into mantle flow models, we show that complete Izanagi plate subduction and margin-wide slab detachment induced a major change in sub-Pacific mantle flow, from dominantly southward before 60 M to north-northeastward after 50 Ma. Our results agree with onshore geology, mantle tomography, and the inferred motion of the Hawaiian hotspot and are consistent with a plate-tectonic process driving the rapid plate-mantle reorganization in the Pacific hemisphere between 60 and 50 Ma, as reflected in tectonic changes in the Pacific and surrounding ocean basins.

Funding

Australian Research Council

History

Publication title

Geophysical Research Letters

Volume

42

Issue

6

Pagination

1732-1740

ISSN

0094-8276

Department/School

Institute for Marine and Antarctic Studies

Publisher

Amer Geophysical Union

Place of publication

2000 Florida Ave Nw, Washington, USA, Dc, 20009

Rights statement

Copyright 2015 American Geophysical Union

Repository Status

  • Open

Socio-economic Objectives

Expanding knowledge in the earth sciences

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