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Ancient mantle in a modern arc: Osmium isotopes in Izu-Bonin-Mariana forearc peridotites

Parkinson, Ian; Hawkesworth, Chris J. and Cohen, Anthony (1998). Ancient mantle in a modern arc: Osmium isotopes in Izu-Bonin-Mariana forearc peridotites. Science, 281 pp. 2011–2013.

DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1126/science.281.5385.2011
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Abstract

Mantle peridotites drilled from the Izu-Bonin-Mariana forearc have unradiogenic 187Os/188Os ratios (0.1193 to 0.1273), which give Proterozoic model ages of 820 to 1230 million years ago. If these peridotites are residues from magmatism during the initiation of subduction 40 to 48 million years ago, then the mantle that melted was much more depleted in incompatible elements than the source of mid-ocean ridge basalts (MORB). This result indicates that osmium isotopes record information about ancient melting events in the convecting upper mantle not recorded by incompatible lithophile isotope tracers. Subduction zones may be a graveyard for ancient depleted mantle material, and portions of the convecting upper mantle may be less radiogenic in osmium isotopes than previously recognized.

Item Type: Journal Article
Copyright Holders: 1998 American Association for the Advancement of Science
ISSN: 1095-9203
Project Funding Details:
Funded Project NameProject IDFunding Body
Not SetNot SetNERC
Academic Unit/Department: Science > Environment, Earth and Ecosystems
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
Item ID: 29091
Depositing User: Ian Parkinson
Date Deposited: 14 Jul 2011 10:02
Last Modified: 14 Jul 2011 10:02
URI: http://oro.open.ac.uk/id/eprint/29091
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