Seton_et_al-2015-Geophysical_Research_Letters.pdf (5.98 MB)
Ridge subduction sparked reorganization of the Pacific plate-mantle system 60-50 million years ago
journal contribution
posted on 2023-05-18, 08:32 authored by Seton, M, Flament, N, Joanne WhittakerJoanne Whittaker, Muller, RD, Gurnis, M, Bower, DJA 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 LettersVolume
42Issue
6Pagination
1732-1740ISSN
0094-8276Department/School
Institute for Marine and Antarctic StudiesPublisher
Amer Geophysical UnionPlace of publication
2000 Florida Ave Nw, Washington, USA, Dc, 20009Rights statement
Copyright 2015 American Geophysical UnionRepository Status
- Open