Arculus, RJ, Ishizuka, O, Bogus, KA et al. (27 more authors) (2015) A record of spontaneous subduction initiation in the Izu–Bonin–Mariana arc. Nature Geoscience, 8 (9). pp. 728-733. ISSN 1752-0894
Abstract
The initiation of tectonic plate subduction into the mantle is poorly understood. If subduction is induced by the push of a distant mid-ocean ridge or subducted slab pull, we expect compression and uplift of the overriding plate. In contrast, spontaneous subduction initiation, driven by subsidence of dense lithosphere along faults adjacent to buoyant lithosphere, would result in extension and magmatism. The rock record of subduction initiation is typically obscured by younger deposits, so evaluating these possibilities has proved elusive. Here we analyse the geochemical characteristics of igneous basement rocks and overlying sediments, sampled from the Amami Sankaku Basin in the northwest Philippine Sea. The uppermost basement rocks are areally widespread and supplied via dykes. They are similar in composition and age—as constrained by the biostratigraphy of the overlying sediments—to the 52–48-million-year-old basalts in the adjacent Izu–Bonin–Mariana fore-arc. The geochemical characteristics of the basement lavas indicate that a component of subducted lithosphere was involved in their genesis, and the lavas were derived from mantle source rocks that were more melt-depleted than those tapped at mid-ocean ridges. We propose that the basement lavas formed during the inception of Izu–Bonin–Mariana subduction in a mode consistent with the spontaneous initiation of subduction.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015 Macmillan Publishers Limited. This is an author produced version of a paper published in Nature Geoscience. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Funding Information: | Funder Grant number NERC (Natural Environment Research Council) NE/M007782/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 10 Sep 2015 08:59 |
Last Modified: | 09 Apr 2021 15:33 |
Published Version: | http://dx.doi.org/10.1038/ngeo2515 |
Status: | Published |
Publisher: | Nature Publishing Group |
Identification Number: | 10.1038/ngeo2515 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:89344 |