Mantle pseudo-isochrons revisited

Rudge, J. F. (2006) Mantle pseudo-isochrons revisited. Earth and Planetary Science Letters, 249 (3-4). pp. 494-513. ISSN 0012-821X DOI 10.1016/j.epsl.2006.06.046

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Abstract

The 2.0 Ga pseudo-isochron age inferred from the mid-ocean ridge basalt 207Pb/204Pb against 206Pb/204Pb diagram is reexamined on the basis of a statistical box model of mantle processes. Simple equations are presented which relate the pseudoisochron age to the decay constants and distribution of heterogeneity ages in the model mantle. In turn this age distribution is simply related to the history of melting. The equations are in good agreement with results from mantle convection simulations. The equations are different from but related to, and more general than, those found previously for mean box models. While the pseudoisochron age does not signify a mean age in the usual sense, in the model presented it is related to a “generalised mean” over the distribution of heterogeneity ages. If a constant melt rate over the Earth's history is assumed, a mean remelting time of 0.5 Ga is required.

Item Type: Article
Uncontrolled Keywords: 2006 AREP IA52 2006 P
Subjects: 05 - Petrology - Igneous, Metamorphic and Volcanic Studies
02 - Geodynamics, Geophysics and Tectonics
Divisions: 02 - Geodynamics, Geophysics and Tectonics
Journal or Publication Title: Earth and Planetary Science Letters
Volume: 249
Page Range: pp. 494-513
Identification Number: 10.1016/j.epsl.2006.06.046
Depositing User: Sarah Humbert
Date Deposited: 16 Feb 2009 13:03
Last Modified: 23 Jul 2013 10:08
URI: http://eprints.esc.cam.ac.uk/id/eprint/639

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